Method for forming silicon-containing materials during a photoexcitation deposition process

Embodiments of the invention generally provide a method for depositing films or layers using a UV source during a photoexcitation process. The films are deposited on a substrate and usually contain a material, such as silicon (e.g., epitaxy, crystalline, microcrystalline, polysilicon, or amorphous), silicon oxide, silicon nitride, silicon oxynitride, or other silicon-containing materials. The photoexcitation process may expose the substrate and/or gases to an energy beam or flux prior to, during, or subsequent a deposition process. Therefore, the photoexcitation process may be used to pre-treat or post-treat the substrate or material, to deposit the silicon-containing material, and to enhance chamber cleaning processes. Attributes of the method that are enhanced by the UV photoexcitation process include removing native oxides prior to deposition, removing volatiles from deposited films, increasing surface energy of the deposited films, increasing the excitation energy of precursors, reducing deposition time, and reducing deposition temperature.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the invention generally relate to a method for depositing silicon-containing materials, and more particularly, embodiments of the invention relate to chemical vapor deposition processes utilizing photoexcitation techniques to deposit silicon based dielectric materials, such as silicon oxide, silicon nitride, silicon oxynitride, silicon, and other silicon materials.

2. Description of the Related Art

Thermal chemical vapor deposition (CVD) of silicon-containing materials, such as silicon nitride, is a front end process used during the manufacture of semiconductor devices. For example, in a thermal CVD process for depositing silicon nitride, thermal energy is utilized for decomposing one or more feedstock chemicals, which includes a silicon precursor, to make a thin film of a silicon nitride on a substrate surface. Conventional thermal CVD processes of silicon-containing materials are typically performed in a batch furnace or a single wafer deposition chamber operating at elevated temperatures typically in excess of 550° C. As device geometries shrink to enable faster integrated circuits, the thermal budget for deposited films must be reduced in order to obtain satisfactory processing results, good production yield and robust device performance. Although some thermal CVD processes for silicon-containing materials having deposition temperatures of less than 550° C. have been proposed, the processes usually lack suitable production worthiness for large scale semiconductor device fabrication. Atomic layer deposition (ALD) processes have also been developed for depositing silicon-containing materials, such as silicon nitride and silicon oxide. While ALD processes have enabled a reduction in processing temperatures of about 550° C., film growth rates are usually extremely slow and therefore cost prohibiting for commercial fabrication.

Thus, there is a need for an improved method of depositing silicon-containing materials, such as silicon, silicon oxide, silicon nitride, and silicon oxynitride, at a temperature of less than about 550° C. while maintaining a high growth rate.

SUMMARY OF THE INVENTION

Embodiments of the invention generally provide a method for depositing films using a UV source during a photoexcitation process. The films are deposited on a substrate and usually contain a material, such as silicon oxide, silicon nitride, silicon oxynitride, silicon (e.g., epitaxy, crystalline, microcrystalline, polysilicon, or amorphous), or other silicon-containing materials (e.g., SiGe, SiC, SiGeC, or doped variants thereof). The photoexcitation process may expose the substrate and/or gases to an energy beam or flux prior to, during, or subsequent a deposition process. Therefore, the photoexcitation process may be used to pre-treat or post-treat the substrate, to deposit the silicon-containing material, and to enhance chamber cleaning processes. Attributes of the method that are enhanced by the UV photoexcitation process include removing native oxides prior to deposition, removing volatiles from deposited films, increasing surface energy, increasing the excitation energy of precursors, reducing deposition time, and reducing deposition temperature.

In one embodiment, a method for forming a silicon material on a substrate is provided which includes positioning a substrate within a process chamber, exposing the substrate to a deposition gas containing an aminosilane precursor, an oxygen precursor, and a nitrogen precursor, exposing the deposition gas to an energy beam derived from a UV-source within the process chamber, and depositing a silicon-containing material on the substrate, such that the silicon-containing material may be amorphous and contain oxygen and nitrogen.

In one example, the substrate may be exposed to the energy beam during a pretreatment process prior to depositing the silicon-containing material. The native oxides may be removed from the substrate during the pretreatment process. In another example, the substrate may be exposed to the energy beam during a post-treatment process after depositing the silicon-containing material. During the pretreatment process or the post-treatment process, the energy beam may have a photon energy within a range from about 2 eV to about 10 eV, for example, from about 3.2 eV to about 4.5 eV. Also, the energy delivery gas may be passed through the energy beam during the pretreatment process or the post-treatment process. The energy delivery gas may be neon, argon, krypton, xenon, argon bromide, argon chloride, krypton bromide, krypton chloride, krypton fluoride, xenon fluorides (e.g., XeF2), xenon chlorides, xenon bromides, fluorine, chlorine, bromine, excimers thereof, radicals thereof, derivatives thereof, or combinations thereof. In one example, the energy delivery gas further contains nitrogen gas or hydrogen gas.

In another embodiment, a method for forming a silicon material on a substrate is provided which includes positioning a substrate containing a monocrystalline silicon-containing surface and a second surface within a process chamber, exposing the substrate to an energy beam derived from a UV-source during a pretreatment process, and exposing the substrate to a deposition gas containing an aminosilane and the energy beam during a deposition process. The method further provides depositing a silicon-containing material epitaxially and selectively over the monocrystalline silicon-containing surface while maintaining the second surface free of the silicon-containing material.

In one example, the monocrystalline silicon-containing surface may contain at least one element, such as germanium, carbon, boron, arsenic, phosphoric, or combinations thereof. In another example, the second surface contains at least one material, such as polycrystalline silicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxynitride, a metal, a metal silicate, or derivatives thereof. Examples provide that the deposition gas may further contain an etchant. The etchant may contain chlorine gas, hydrogen chloride, tetrachlorosilane, derivatives thereof, or combinations thereof.

In another embodiment, a method for forming a silicon material on a substrate is provided which includes positioning a substrate containing a native oxide layer within a process chamber and exposing the substrate to an energy beam derived from a UV-source to remove the native oxide layer during a pretreatment process. The method further provides exposing the substrate to a deposition gas containing an aminosilane and the energy beam during a deposition process, depositing a polycrystalline silicon-containing material on the substrate, and exposing the substrate to the energy beam during a post-treatment process after depositing the polycrystalline silicon-containing material.

In another embodiment, a method for forming a silicon material on a substrate is provided which includes positioning a substrate containing a native oxide layer within a process chamber, exposing the substrate to an energy beam derived from a UV-source to remove the native oxide layer during a pretreatment process, and depositing a silicon oxide material on the substrate during a deposition process. The method further provides that during the deposition process, the substrate may be exposed to a deposition gas containing an aminosilane and an oxygen precursor, and deposition gas is exposed to the energy beam within the process chamber. The oxygen precursor may contain atomic oxygen, oxygen, ozone, water, hydrogen peroxide, radicals thereof, derivatives thereof, or combinations thereof.

In another embodiment, a method for forming a silicon material on a substrate is provided which includes positioning a substrate within a process chamber, depositing a silicon oxide material on the substrate during a deposition process, and exposing the substrate to the energy beam after depositing the silicon oxide material during a post-treatment process. In another embodiment, the substrate is exposed to an energy beam derived from a UV-source during a pretreatment process prior to depositing the silicon oxide material. The deposition process provides exposing the substrate to a deposition gas containing an aminosilane and an oxygen precursor, and exposing the deposition gas to the energy beam.

In one example, a silicon oxide material containing nitrogen may be formed by providing a nitrogen precursor within the deposition gas. The nitrogen precursor may contain atomic nitrogen, nitrogen, azide, ammonia, hydrazine, amine compounds, hydrazine compounds, azide compounds, radicals thereof, derivatives thereof, or combinations thereof. In other examples, the substrate may be exposed to a nitridation process after depositing a silicon oxide material on the substrate.

In another embodiment, a method for forming a silicon material on a substrate is provided which includes positioning a substrate within a process chamber and exposing the substrate to a deposition gas that contains a silicon-containing precursor, an oxygen precursor, and a nitrogen precursor. The method further includes exposing the deposition gas to an energy beam derived from a UV-source within the process chamber, and depositing a silicon-containing material on the substrate, such that the silicon-containing material is amorphous and comprises oxygen and nitrogen.

In another embodiment, a method for forming a silicon material on a substrate is provided which includes positioning a substrate within a process chamber, exposing the substrate to a deposition gas containing a silicon-containing precursor and an oxygen precursor, exposing the deposition gas to an energy beam derived from a UV-source within the process chamber, and depositing a silicon oxide material on the substrate. In another embodiment, a method for forming a silicon material on a substrate is provided which includes positioning a substrate within a process chamber, exposing the substrate to a deposition gas containing tetraethoxysilane and an oxygen precursor, exposing the deposition gas to an energy beam derived from a UV-source within the process chamber, and depositing a silicon oxide material on the substrate.

In one example, the silicon-containing precursor is an alkoxysilane compound. The alkoxysilane compound may have the chemical formula of (RO)nSiR′(4-n), wherein n=1, 2, 3, or 4, each R, independently, may be methyl, ethyl, propyl, or butyl, and each R′, independently, may be hydrogen, a halogen group, methyl, ethyl, propyl, or butyl. In a specific example, the alkoxysilane compound is tetraethoxysilane (TEOS). In another example, the silicon-containing precursor is a halosilane compound. The halosilane compound may include hexachlorodisilane, tetrachlorosilane, dichlorosilane, derivatives thereof, or combinations thereof. In other example, the silicon-containing precursor may include silane, disilane, trisilane, methylsilane, derivatives thereof, or combinations thereof. The oxygen precursor may contain atomic oxygen, oxygen, ozone, water, hydrogen peroxide, radicals thereof, derivatives thereof, or combinations thereof. The nitrogen precursor may contain atomic nitrogen, nitrogen, azide, ammonia, hydrazine, amine compounds, hydrazine compounds, azide compounds, radicals thereof, derivatives thereof, or combinations thereof.

To facilitate understanding, identical reference numerals have been used, wherever possible, to designate identical elements that are common to the figures. It is contemplated that elements and/or process steps of one embodiment may be beneficially incorporated in other embodiments without additional recitation.

DETAILED DESCRIPTION

Embodiments of the invention provide a process for depositing a silicon-containing material onto a substrate. Silicon-containing materials include silicon oxide, silicon nitride, and silicon oxynitride, as well as silicon materials that may contain germanium, carbon, dopants, or combinations thereof. Many of the embodiments described herein are advantageously performed utilizing temperatures of less than about 550° C. Although some examples of the processes are described with reference to a single wafer thermal-chemical vapor deposition chamber (e.g., process chamber1100illustrated inFIG. 7), other processes may be beneficially practiced in other deposition systems, such as a batch chamber. Process chambers which may be used during the deposition processes as described herein include a SINGEN® Plus chamber and a POLYGEN™ chamber, each available from Applied Materials, Inc., located in Santa Clara, Calif. An excimer, such as a Xe-excimer, may be integrated into theses process chambers and used as an UV-source. In one example, a useful Xe-excimer source at 172 nm is the XERADEX® 20, available from Osram Sylvania, located in Westfield, Ind. Moreover, although deposition processes for silicon oxide, silicon nitride, silicon oxynitride, and silicon materials are described below, it is contemplated that the process may be adapted to deposit other silicon-containing materials, such as metal suicides and metal silicates.

Besides conventional CVD, other useful processes for depositing silicon-containing materials during photoexcitation processes or UV-assisted processes include pulsed-CVD and atomic layer deposition (ALD). During a pulsed-CVD process, a silicon precursor and a reactant (e.g., another precursor, a reductant, or an oxidizer) are co-flowed and pulsed into the process chamber. In one embodiment, the substrate is sequentially exposed to a deposition gas containing the silicon precursor and the reactant. In another embodiment, the substrate is sequentially exposed to the silicon precursor and the reactant. During an ALD process, the silicon precursor and the reactant are sequentially pulsed into the process chamber. In one embodiment, the substrate is sequentially exposed to the silicon precursor and the reactant during an ALD process. Plasma enhanced or thermally enhanced deposition techniques may be used during either ALD or CVD processes. Silicon-containing materials may be deposited on a single substrate or a batch of substrates during the deposition processes described herein.

Processes for Depositing Silicon-Containing Materials

FIGS. 1-4illustrate flow chart diagrams of processes100,200,300, and400for depositing silicon-containing materials, as described by embodiments herein. Processes100,200,300, and400may be performed within process chamber1100, such as described by examples herein, or by other suitable chamber and equipment. The silicon-containing material may include silicon nitride, silicon oxide, silicon oxynitride, silicon materials (epitaxy, polysilicon, or amorphous), such as silicon, silicon carbide, silicon germanium, silicon germanium carbide, doped variants thereof, derivatives thereof, or combinations thereof. Silicon-containing materials may be deposited on a substrate, such as a silicon nitride material by process100(FIG. 1), a silicon oxide material by process200(FIG. 2), a silicon oxynitride material by process300(FIG. 3), or a silicon material by process400(FIG. 4) as described by embodiments herein. The silicon-containing materials may be deposited as layers on a substrate to form electronic features, such as a MOSFET transistor (FIGS. 5A-5B), a bi-polar transistor (FIG. 6), or other silicon-containing layers, as well as within a photovoltaic cell.

Silicon Nitride Materials

FIG. 1depicts a flow diagram of process100for depositing a silicon nitride material, as described by embodiments herein. The substrate may be positioned within a process chamber (step110), optionally exposed to a pretreatment process (step120), and heated to a predetermined temperature (step130). Subsequently, a silicon nitride material may be deposited on the substrate (step140). The substrate may be optionally exposed to post-deposition treatment process (step150) and the process chamber may be optionally exposed to a chamber clean process (step160).

The substrate may be positioned within a process chamber during step110. The process chamber may be a single wafer chamber or a batch chamber containing multiple wafers or substrates (e.g., 25, 50, 100, or more). The substrate may be maintained in a fixed position, but preferably, is rotated by a support pedestal. Optionally, the substrate may be indexed during one or more steps of process100.

Process chamber1100, depicted inFIG. 7, may be used during process100to deposit silicon nitride materials on substrate1122as described by examples herein. In one example, substrate1122may be rotated on substrate support pedestal1124within process chamber1100at a rate of up to about 120 rpm (revolutions per minute). Alternatively, substrate1122may be positioned on substrate support pedestal1124and not rotated during the deposition process.

In one embodiment, the substrate is optionally exposed to at least one pretreatment process during step120. The substrate surface may contain native oxides that are removed during a pretreatment process. The substrate may be pretreated with an energy beam generated by direct photoexcitation system to remove the native oxides from the substrate surface prior to depositing a silicon nitride material during step140. A process gas may be exposed to the substrate during the pretreatment process. The process gas may contain argon, nitrogen, helium, hydrogen, forming gas, or combinations thereof. The pretreatment process may last for a time period within a range from about 2 minutes to about 10 minutes to facilitate native oxide removal during a photoexcitation process. Also, the substrate may be heated during step120to a temperature within a range from about 100° C. to about 800° C., preferably, from about 200° C. to about 600° C., and more preferably, from about 300° C. to about 500° C., to facilitate native oxide removal during process100.

Examples provide that substrate1122may be exposed to an energy beam produced by lamp1170during step120. Lamp1170may provide an energy beam having a photon energy within a range from about 2 eV to about 10 eV. In another example, lamp1170provides an energy beam of UV radiation having a wavelength within a range from about 126 nm to about 351 nm. Lamp1170may be energized for a period sufficient to remove oxides. The energization period is selected based upon the size and geometry of window1174(which corresponds to the exposed area of substrate1122) and the substrate rotation speed. In one embodiment, lamp1170is energized for a time period within a range from about 2 minutes to about 10 minutes to facilitate native oxide removal during a photoexcitation process. In one example, substrate1122may be heated to a temperature within a range from about 100° C. to about 800° C. during step120. In another example, substrate1122may be heated to a temperature within a range from about 300° C. to about 500° C. during step120, while lamp1170provides an energy beam having a photon energy within a range from about 2 eV to about 10 eV for a time period within a range from about 2 minutes to about 5 minutes to facilitate native oxide removal. In one example, the energy beam has a photon energy within a range from about 3.2 eV to about 4.5 eV for about 3 minutes.

In another embodiment, native oxide removal may be augmented by a photoexcitation process in the presence of a process gas containing an energy delivery gas during a pretreatment process at step120. The energy delivery gas may be neon, argon, krypton, xenon, argon bromide, argon chloride, krypton bromide, krypton chloride, krypton fluoride, xenon fluorides (e.g., XeF2), xenon chlorides, xenon bromides, fluorine, chlorine, bromine, excimers thereof, radicals thereof, derivatives thereof, or combinations thereof. In some embodiments, the process gas may also contain nitrogen gas (N2), hydrogen gas (H2), forming gas (e.g., N2/H2or Ar/H2) besides at least one energy delivery gas.

In one example, substrate1122may be exposed to a process gas containing an energy delivery gas by providing the process gas to interior volume1104of process chamber1100during step120. The energy delivery gas may be provided through flow control ring1142from gas panel1136. The proximately of the process gas to lamp1170compared to substrate1122readily excites the energy delivery gas therein. As the energy delivery gas de-excites and moves closer to substrate1122, the energy is efficiently transferred to the surface of substrate1122, thereby facilitating the removal of native oxides.

In another embodiment, native oxide removal may be augmented by a photoexcitation process in the presence of a process gas containing an organic vapor during the pretreatment process at step120. In one example, the substrate may be exposed to the process gas containing a cyclic aromatic hydrocarbon. The cyclic aromatic hydrocarbon may be in the presence of UV radiation. Monocyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons that are useful during a pretreatment process include quinone, hydroxyquinone (hydroquinone), anthracene, naphthalene, phenanthracene, derivatives thereof, or combinations thereof. In another example, the substrate may be exposed to the process gas containing other hydrocarbons, such as unsaturated hydrocarbons, including ethylene, acetylene (ethyne), propylene, alkyl derivatives, halogenated derivates, or combinations thereof. In another example, the organic vapor may contain alkane compounds during the pretreatment process at step120.

In one example, the UV radiation having a wavelength within a range from about 126 nm to about 351 nm may be generated by a lamp during step120. In another embodiment, polycyclic aromatic hydrocarbons may remove native oxides in the presence of UV radiation by reacting with oxygen atoms within the native oxides. In another embodiment, native oxides may be removed by exposing the substrate to quinone or hydroxyquinone while forming derivative products. The derivative product may be removed from the process chamber by a vacuum pumping process.

At step130, the substrate may be heated to a predetermined temperature during or subsequent to the pretreatment process. The substrate is heated prior to depositing the silicon nitride material at step140. The substrate may be heated by an embedded heating element within the substrate support, the energy beam (e.g., UV-source), or combinations thereof. Generally, the substrate is heated long enough to obtain the predetermined temperature, such as for a time period within a range from about 15 seconds to about 30 minutes, preferably, from about 30 seconds to about 20 minutes, and more preferably, from about 1 minute to about 10 minutes. In one embodiment, the substrate may be heated to a temperature within a range from about 200° C. to about 1,000° C., preferably, from about 400° C. to about 850° C., and more preferably, from about 550° C. to about 800° C. In another embodiment, the substrate may be heated to a temperature of less than about 550° C., preferably, less than about 450° C.

In one example, substrate1122may be heated to the predetermined temperature within process chamber1100. The predetermined temperature may be within a range from about 300° C. to about 500° C. Substrate1122may be heated by applying power from power source1116to the resistive heating element (i.e., the heater1120).

In one embodiment, a silicon nitride material is deposited on the substrate during a deposition process at step140. The silicon nitride material may be formed by exposing the substrate to at least one deposition gas during the deposition process. In one example, the deposition process is a CVD process having a deposition gas that may contain a silicon precursor and a nitrogen precursor or a precursor containing both silicon and nitrogen sources. Alternatively, the deposition process may be an ALD process having at least two deposition gases, such that, the substrate is sequentially exposed to a silicon precursor and a nitrogen precursor. The deposition process may be a thermal process, a radical process, or a combination thereof. For example, the substrate may be exposed to a process gas in the presence of an energy beam generated by a direct photoexcitation system.

Examples of suitable nitrogen precursors for forming silicon nitride materials at step140include ammonia (NH3), hydrazine (N2H4), organic amines, organic hydrazines, organic diazines (e.g., methyldiazine ((H3H)NNH)), silylazides, silylhydrazines, hydrogen azide (HN3), hydrogen cyanide (HCN), atomic nitrogen (N), nitrogen (N2), derivatives thereof, or combinations thereof. Organic amines as nitrogen precursors include RxNH3-x, where each R is independently an alkyl group or an aryl group and x is 1, 2, or 3. Examples of organic amines include trimethylamine ((CH3)3N), dimethylamine ((CH3)2NH), methylamine ((CH3)NH2)), triethylamine ((CH3CH2)3N), diethylamine ((CH3CH2)2NH), ethylamine ((CH3CH2)NH2)), tertbutylamine (((CH3)3C)NH2), derivatives thereof, or combinations thereof. Organic hydrazines as nitrogen precursors include RxN2H4-x, where each R is independently an alkyl group or an aryl group and x is 1, 2, 3, or 4. Examples of organic hydrazines include methylhydrazine ((CH3)N2H3), dimethylhydrazine ((CH3)2N2H2), ethylhydrazine ((CH3CH2)N2H3), diethylhydrazine ((CH3CH2)2N2H2), tertbutylhydrazine (((CH3)3C)N2H3), ditertbutylhydrazine (((CH3)3C)2N2H2), radicals thereof, plasmas thereof, derivatives thereof, or combinations thereof.

In one embodiment, the nitrogen precursors ideally contain a nitrogen-nitrogen single bond (i.e., N—N single bond) for decomposition of the nitrogen precursor at low temperatures. Additionally, when a silicon precursor and nitrogen precursor are used in the process gas mix, some amount of a nitrogen precursor may be included in the gas mix for additional control over the composition of the deposited layer during deposition. In a preferred example, the nitrogen precursor is ammonia. The nitrogen precursor generally disassociate at a temperature of less than about 500° C. with a high vapor pressure at room temperature. Examples of suitable nitrogen precursors and the respective vapor pressure include methylamine having a vapor pressure of about 353 kPa at 25° C., methylhydrazine having a vapor pressure of about 66 kPa at 25° C., and hydrocyanic acid having a vapor pressure of about 98.8 kPa at 25° C. (e.g., aqueous hydrogen cyanide solution).

Silicon precursors that may be used to produce a silicon nitride material by the UV-assisted chemical vapor deposition at sufficiently high deposition rates while at a low temperatures include compounds having one or more Si—N bonds or Si—Cl bonds, such as bis(tertbutylamino)silane (BTBAS or (tBu(H)N)2SiH2) or hexachlorodisilane (HCD or Si2Cl6). Combination of a Si—Cl functional group (bond) and a Si—N functional group (bond) has been observed to improved step coverage and microloading especially for the ever decreasing temperatures at suitable deposition rates. The number of Si—Cl groups can be varied relative to the number of Si—N groups.

Silicon precursors having preferred bond structures described above have the chemical formulas:
R2NSi(R′2)Si(R′2)NR2(aminodisilanes),  (I)
R3SiN3(silylazides), or  (II)
R′3SiNRNR2(silylhydrazines).  (III)

In the above chemical formulas, R and R′ may be one or more functional groups independently selected from the group of a halogen, an organic group having one or more double bonds, an organic group having one or more triple bonds, an aliphatic alkyl group, a cyclical alkyl group, an aromatic group, an organosilyl group, an alkylamino group, or a cyclic group containing N or Si, or combinations thereof. Examples of suitable functional groups on silicon precursors include chloro (—Cl), methyl (—CH3), ethyl (—CH2CH3), isopropyl (—CH(CH3)2), tertbutyl (—C(CH3)3), trimethylsilyl (—Si(CH3)3), pyrrolidine, or combinations thereof. It is believed that many of the silicon precursors or the nitrogen precursors described herein may decompose or disassociate at a low temperature, such as about 550° C. or less.

Other examples of suitable silicon precursors include silylazides R3—SiN3and silylhydrazine class of precursors R3SiNRNR2, linear and cyclic with any combination of R groups. The R groups may be H or any organic functional group such as methyl, ethyl, propyl, butyl, and the like (CXHY). The R groups attached to Si can optionally be another amino group NH2or NR2. One benefit of using a silicon-nitrogen precursor is that silicon and nitrogen are simultaneously delivered while avoiding the presence of chlorine to yield films with good step coverage and minimal pattern dependence (so-called pattern loading) without the undesirable ammonium chloride particle formation problematic to other conventions Si—N film precursors. Examples of specific silylazide compounds include trimethylsilylazide ((CH3)3SiN3)(available from United Chemical Technologies, located in Bristol, Pa.) and tris(dimethylamine)silylazide (((CH3)2N)3SiN3). An example of a specific silylhydrazine compound is 1,1-dimethyl-2-dimethylsilylhydrazine ((CH3)2HSiNHN(CH3)2). In another embodiment, the silicon-nitrogen precursor may be at least one of (R3Si)3N, (R3Si)2NN(SiR3)2and (R3Si)NN(SiR3), wherein each R is independently hydrogen or an alkyl such as methyl, ethyl, propyl, butyl, phenyl, or combinations thereof. Examples of suitable silicon-nitrogen precursor include trisilylamine ((H3Si)3N), (H3Si)2NN(SiH3)2, (H3Si)NN(SiH3), or derivatives thereof.

In one example, a silicon nitride material may be deposited on substrate1122within process chamber1100during a deposition process at step140. In one embodiment, substrate1122may be exposed to a process gas containing a silicon precursor and a nitrogen precursor during a CVD process. The silicon and nitrogen precursors are generally provided from gas panel1136to interior volume1104of chamber body1102through flow control ring1142.

In one embodiment, the nitrogen precursor and the silicon precursor may be introduced at step140into process chamber or exposed to substrate1122by inlet port1134simultaneously, such as during a traditional CVD process or sequentially, such as during an ALD process. The ALD process may expose the substrate to at least two deposition gases, such that, the substrate is sequentially exposed to a silicon precursor and a nitrogen precursor. Although one gas line1140is shown disposed between gas panel1136and inlet port1134, it is contemplated that the silicon precursor and the nitrogen precursor are provided to process chamber1100in separate gas lines. The temperature may be controlled for each gas line.

A description of CVD and ALD processes and apparatuses that may be modified (e.g., incorporating a UV radiation source) and chemical precursors that may be useful for depositing silicon nitride materials are further disclosed in commonly assigned U.S. Pat. Nos. 6,677,247, 6,869,838, and 6,825,134, and commonly assigned U.S. Ser. No. 09/964,075, filed Sep. 25, 2001, and published as US 2003-0059535, U.S. Ser. No. 10/263,555, filed May 16, 2002, and published as US 2003-0215570, U.S. Ser. No. 10/898,547, filed Jul. 23, 2004, and published as US 2006-0019032, U.S. Ser. No. 11/155,646, filed Jul. 17, 2005, U.S. Ser. No. 10/970,317, filed Oct. 20, 2004, and published as US 2006-0084283, and U.S. Ser. No. 10/688,797, filed Oct. 17, 2003, and published as US 2004-0224089, which are all herein incorporated by reference in their entirety.

As the silicon precursor and the nitrogen precursor may be combined in the process chamber, a silicon-containing material, such as a silicon nitride material, is formed on the substrate surface. The deposited silicon nitride material exhibits good film qualities such as reflective index and wet etch rate. In one embodiment, the silicon nitride material may be deposited at a rate within a range from about 10 Å/min to about 500 Å/min and is deposited to a thickness within a range from about 10 Å to about 1,000 Å. Silicon nitride materials may have a chemical formula such as SixNy, wherein a nitrogen:silicon atomic ratio (Y/X) is about 1.33 or less, for example, Si3N4. In one embodiment, the materials formed as described herein exhibits low hydrogen content and includes a small amount of carbon doping, which enhances boron retention in PMOS devices. In another embodiment, a halogen-free silicon precursor improves the wet etch rate.

A carrier gas may be provided during step140to control the partial pressure of the nitrogen precursor and the silicon precursor. The total internal pressure of a single wafer process chamber may be at a pressure within a range from about 100 mTorr to about 740 Torr, preferably, from about 250 mTorr to about 100 Torr, and more preferably, from about 500 mTorr to about 50 Torr. In one example, the internal pressure of the process chamber is maintained at a pressure of about 10 Torr or less, preferably, about 5 Torr or less, and more preferably, about 1 Torr or less. In some embodiments, the carrier gas may be provided to control the partial pressure of the nitrogen precursor or the silicon precursor within a range from about 100 mTorr to about 1 Torr for batch processing systems. Examples of suitable carrier gases include nitrogen, hydrogen, argon, helium, forming gas, or combinations thereof.

The substrate, the silicon precursor, and/or the nitrogen precursor may be exposed to an energy beam or a flux of energy generated by the photoexcitation system during the deposition process at step140. The use of the energy beam advantageously increases the deposition rate and improves surface diffusion or mobility of atoms within the silicon nitride material to create active sites for incoming reactive species. In one embodiment, the beam has energy within a range from about 3.0 eV to about 9.84 eV. Also, the energy beam may have a wavelength within a range from about 126 nm to about 450 nm.

In one example, lamp1170of direct photoexcitation system1192and/or lamp1184of remote photoexcitation system1182provides an energy beam to supply the excitation energy of at least one of the silicon precursor or the nitrogen precursor. The high deposition rate and the low deposition temperature produce a film having tunable properties with minimal parasitic side reactions. In one embodiment, the energy beam or flux may have a photon energy within a range from about 4.5 eV to about 9.84 eV. The substrate surface and the process gases may also be excited by lamps1170and1184.

Gas phase excitation and surface reactions are controlled by UV excimer selection. For example, optical excitation of Si2H6may be achieved by using UV photons of hv>4.5 eV and hv>8 eV (λ<155 nm. Accordingly, intermediates of silanes—and NH3* (405 nm), NH2* (470.7 nm), NH* (336 nm) (with * indicating the compound in an excited state) enhances cross-linking between Si and N which may cause Si—N bond distortion in the SiN network, desirable for increasing film tensile stress.

In another embodiment, the substrate containing the silicon nitride material (formed in step140) is exposed to a post-deposition treatment process during step150. The post-deposition treatment process increases the substrate surface energy after deposition, which advantageously removes volatiles and/or other film contaminants (such as by reducing the hydrogen content) and/or anneals the deposited film. A lower concentration of hydrogen from the deposited material advantageously increases tensile stress of the film. At least one lamp (e.g., lamps1170or1184) may alternatively be utilized to energize an energy delivery gas which is exposed to the substrate to increase the surface energy of the substrate after deposition and to remove volatiles and/or other films.

Optionally, at step150, an energy delivery gas may be provided to interior volume1104of process chamber1100. Examples of suitable energy delivery gases include nitrogen, hydrogen, helium, argon, and combinations thereof. Examples provide that substrate1122is treated with an energy beam or flux of energy generated by photoexcitation system1144during step150. In one example, lamp1170of direct photoexcitation system1192provides an energy beam to supply the surface energy of substrate1122during step150. In another example for annealing the silicon nitride material, the energy beam or flux may have a photon energy within a range from about 3.53 eV to about 9.84 eV. Also, lamp1170may produce an energy beam having a wavelength within a range from about 126 nm to about 351 nm. Generally, lamp1170may be energized for a time period within a range from about 1 minute to about 10 minutes to facilitate post deposition treatment by photoexcitation.

In one example, volatile compounds or contaminants may be removed from the deposited film surface by exposing the substrate to an energy beam having a photon energy within a range from about 3.2 eV to about 4.5 eV is generated by lamp1170and/or lamp1184is utilized to dissociate Si—H (3.21 eV), N—H (3.69 eV), NH—H (3.86 eV), H2N—H (4.47 eV), and Si—N (4.51 eV) radicals within process chamber1100. Thus, excimer lamps, such as XeBr* (283 nm/4.41 eV), Br2* (289 nm/4.29 eV), XeCl* (308 nm/4.03 eV), I2* (342 nm/3.63 eV), XeF* (351 nm/3.53 eV) may be selected to dissociate the Si—H and N—H bonds to remove hydrogen from the SiN network. It is contemplated that the rotational speed of the substrate may be changed, for example, by increasing the rotation speed in step150relative to the preceding deposition step.

In another embodiment, the substrate may be removed from the process chamber and the process chamber is subsequently exposed to a chamber clean process during step160. The process chamber may be cleaned using a photoexcited cleaning agent. Alternatively, the cleaning agent may be provided from the remote plasma source1190. In one embodiment, the cleaning agent includes fluorine.

Examples provide that the cleaning agent may be photoexcited within process chamber1100using lamp1170, or remotely from process chamber1100using lamp1184. In one example, lamp1170may be used to maintain the excitation level of cleaning agents formed by remote plasma source (RPS)1190.

Process chamber1100may be cleaned during a chamber clean process to enhance deposition performance. For example, the chamber clean process may be used to remove contaminants contained on windows1174and1186, thereby minimizing transmission losses of the energy beam or flux traveling through window1174or1186and maximizing the energy transferred to the gases and surfaces. It is also contemplated that windows1174and1186may be cleaned using a photoexcited agent formed from RPS1190during the chamber clean process. Windows1174and1186may be cleaned with greater frequency than process chamber1100, for example, process chamber1100may be cleaned using RPS1190after processing a number of substrates while windows1174and1186are cleaned after processing each substrate.

The elemental composition of the silicon nitride material deposited during step140may be predetermined by controlling the concentration or flow rate of the chemical precursors, namely the silicon precursor and the nitrogen precursor. Film properties may be tailored for specific applications by controlling the relative concentrations of Si, O, N, C, and H within the silicon nitride material. In one embodiment, the elemental concentrations of silicon, nitrogen, and hydrogen may be tuned by varying the range of the UV energy during or subsequent the deposition process. The film properties include wet etch rate, dry etch rate, stress, dielectric constant, and the like. For example, by reducing the hydrogen content, the deposited material may have a higher tensile stress. In another example, by reducing the carbon content, the deposited material may have a lower electrical resistance.

Additionally, when using N—Si—R or N—Si—Si—R type of precursors, the dissociation of the silicon-source molecule takes place at lower temperatures, thereby enabling lower temperature processing. The functional group (e.g., Si—R or Si—Si) is weakly bonded compared to Si—N bond, since the bond enthalpy of Si—N (about 470 kJ/mol) is higher than that of Si—Si (about 327 kJ/mol) or Si—C (about 452 kJ/mol). Furthermore, the nitrogen precursors used in this invention that contain a carbon and hydrogen function group, which react with R or Si—R from N—Si—R or N—Si—Si—R in the silicon precursor, allow the R group to become dissociated and more easily removed than without reacting with nitrogen precursor. The nitrogen precursor provides nitrogen and carbon sources to the silicon nitride material. Thus, embodiments of the methods may advantageously facilitate low temperature processing, e.g., at temperatures of less than about 550° C.

Silicon nitride materials deposited during process100as described herein may be used throughout electronic features/devices due to several physical properties. Silicon nitride materials are electric insulators, as well as barrier materials. The barrier properties inhibit ion diffusion between dissimilar materials or elements when a silicon nitride material is placed therebetween, such as a gate material and an electrode, or between low dielectric constant porous materials and copper. Therefore, a silicon nitride material may be used in barrier layers, protective layers, off-set layers, spacer layers, and capping layers. Another physical property of silicon nitride materials is a high degree of hardness. In some applications, a silicon nitride material may be used as a protective coating for various optical devices as well as tools. Also, silicon nitride materials may be selectively etched relative to silicon oxide, i.e., silicon nitride may be used as an etch stop layer under a silicon oxide dielectric layer to accurately control etch depth without over or under etching. Silicon nitride materials may be formed containing a predetermined concentration of carbon and hydrogen to provide a desirable film stress, such as high tensile stress. In one embodiment, silicon nitride materials may be deposited during process100as layers on a substrate to form electronic features, such as a MOSFET transistor (FIGS. 5A-5B), a bi-polar transistor (FIG. 6), or other silicon-containing layers. In another embodiment, silicon nitride materials deposited by process100may be used throughout photovoltaic cell applications, such as to form a solar cell.

Silicon Oxide Materials

FIG. 2depicts a flow diagram of process200for depositing a silicon oxide material, as described by embodiments herein. The substrate may be positioned within a process chamber (step210), optionally exposed to a pretreatment process (step220), and heated to a predetermined temperature (step230). Subsequently, a silicon oxide material may be deposited on the substrate (step240). The substrate may be optionally exposed to post-deposition treatment process (step250) and the process chamber may be optionally exposed to a chamber clean process (step260).

The substrate may be positioned within a process chamber during step210. The process chamber may be a single wafer chamber or a batch chamber containing multiple wafers or substrates (e.g., 25, 50, 100, or more). The substrate may be maintained in a fixed position, but preferably, is rotated by a support pedestal. Optionally, the substrate may be indexed during one or more steps of process200.

Process chamber1100, depicted inFIG. 7, may be used during process200to deposit silicon oxide materials on substrate1122as described by examples herein. In one example, substrate1122may be rotated on substrate support pedestal1124within process chamber1100at a rate of up to about 120 rpm. Alternatively, substrate1122may be positioned on substrate support pedestal1124and not rotated during the deposition process.

In one embodiment, the substrate is optionally exposed to at least one pretreatment process during step220. The substrate surface may contain native oxides that are removed during a pretreatment process. The substrate may be pretreated with an energy beam generated by direct photoexcitation system to remove the native oxides from the substrate surface prior to depositing a silicon oxide material during step240. A process gas may be exposed to the substrate during the pretreatment process. In one embodiment, the process gas may contain argon, nitrogen, helium, hydrogen, forming gas, or combinations thereof. The pretreatment process may last for a time period within a range from about 2 minutes to about 10 minutes to facilitate native oxide removal during a photoexcitation process. Also, the substrate may be heated during step220to a temperature within a range from about 100° C. to about 800° C., preferably, from about 200° C. to about 600° C., and more preferably, from about 300° C. to about 500° C., to facilitate native oxide removal during process200.

Examples provide that substrate1122may be exposed to an energy beam produced by lamp1170during step220. Lamp1170may provide an energy beam having a photon energy within a range from about 2 eV to about 10 eV, for example, from about 3.2 eV to about 4.5 eV. In another example, lamp1170provides an energy beam of UV radiation having a wavelength within a range from about 126 nm to about 351 nm. Lamp1170may be energized for a period sufficient to remove oxides. The energization period is selected based upon the size and geometry of window1174(which corresponds to the exposed area of substrate1122) and the substrate rotation speed. In one embodiment, lamp1170is energized for a time period within a range from about 2 minutes to about 10 minutes to facilitate native oxide removal during a photoexcitation process. In one example, substrate1122may be heated to a temperature within a range from about 100° C. to about 800° C. during step220. In another example, substrate1122may be heated to a temperature within a range from about 300° C. to about 500° C. during step220, while lamp1170provides an energy beam having a photon energy within a range from about 2 eV to about 10 eV for a time period within a range from about 2 minutes to about 5 minutes to facilitate native oxide removal. In one example, the energy beam has a photon energy within a range from about 3.2 eV to about 4.5 eV for about 3 minutes.

In another embodiment, native oxide removal may be augmented by a photoexcitation process in the presence of a process gas containing an energy delivery gas during a pretreatment process at step220. The energy delivery gas may be neon, argon, krypton, xenon, argon bromide, argon chloride, krypton bromide, krypton chloride, krypton fluoride, xenon fluorides (e.g., XeF2), xenon chlorides, xenon bromides, fluorine, chlorine, bromine, excimers thereof, radicals thereof, derivatives thereof, or combinations thereof. In another embodiment, the energy delivery gas may contain ozone, oxygen, hydrogen, water, hydroxyls, radicals thereof, plasma thereof, or combinations thereof. In some embodiments, the process gas may also contain nitrogen gas (N2), hydrogen gas (H2), forming gas (e.g., N2/H2or Ar/H2) besides at least one energy delivery gas.

In one example, substrate1122may be exposed to a process gas containing an energy delivery gas by providing the process gas to interior volume1104of process chamber1100during step220. The energy delivery gas may be provided through flow control ring1142from gas panel1136. The proximately of the process gas to lamp1170compared to substrate1122readily excites the energy delivery gas therein. As the energy delivery gas de-excites and moves closer to substrate1122, the energy is efficiently transferred to the surface of substrate1122, thereby facilitating the removal of native oxides.

In another embodiment, native oxide removal may be augmented by a photoexcitation process in the presence of a process gas containing an organic vapor during the pretreatment process at step220. In one example, the substrate may be exposed to the process gas containing a cyclic aromatic hydrocarbon. The cyclic aromatic hydrocarbon may be in the presence of UV radiation. Monocyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons that are useful during a pretreatment process include quinone, hydroxyquinone (hydroquinone), anthracene, naphthalene, phenanthracene, derivatives thereof, or combinations thereof. In another example, the substrate may be exposed to the process gas containing other hydrocarbons, such as unsaturated hydrocarbons, including ethylene, acetylene (ethyne), propylene, alkyl derivatives, halogenated derivates, or combinations thereof. In another example, the organic vapor may contain alkane compounds during the pretreatment process at step220.

In one example, the UV radiation having a wavelength within a range from about 126 nm to about 351 nm may be generated by a lamp during step220. In another embodiment, polycyclic aromatic hydrocarbons may remove native oxides in the presence of UV radiation by reacting with oxygen atoms within the native oxides. In another embodiment, native oxides may be removed by exposing the substrate to quinone or hydroxyquinone while forming derivative products. The derivative product may be removed from the process chamber by a vacuum pumping process.

At step230, the substrate may be heated to a predetermined temperature during or subsequent to the pretreatment process. The substrate is heated prior to depositing the silicon oxide material at step240. The substrate may be heated by an embedded heating element within the substrate support, the energy beam (e.g., UV-source), or combinations thereof. Generally, the substrate is heated long enough to obtain the predetermined temperature, such as for a time period within a range from about 15 seconds to about 30 minutes, preferably, from about 30 seconds to about 20 minutes, and more preferably, from about 1 minute to about 10 minutes. In one embodiment, the substrate may be heated to a temperature within a range from about 200° C. to about 1,000° C., preferably, from about 400° C. to about 850° C., and more preferably, from about 500° C. to about 900° C. In another embodiment, the substrate may be heated to a temperature of less than about 550° C., preferably, less than about 450° C.

In one example, substrate1122may be heated to the predetermined temperature within process chamber1100. The predetermined temperature may be within a range from about 300° C. to about 500° C. Substrate1122may be heated by applying power from power source1116to the resistive heating element (i.e., the heater1120).

In one embodiment, a silicon oxide material is deposited on the substrate during a deposition process at step240. The silicon oxide material may be formed by exposing the substrate to at least one deposition gas during the deposition process. In one example, the deposition process is a CVD process having a deposition gas that may contain a silicon precursor and an oxygen precursor or a precursor containing both silicon and oxygen sources. Alternatively, the deposition process may be an ALD process having at least two deposition gases, such that, the substrate is sequentially exposed to a silicon precursor and an oxygen precursor. The deposition process may be a thermal process, a radical process, or a combination thereof. For example, the substrate may be exposed to a process gas in the presence of an energy beam generated by a direct photoexcitation system.

Examples of suitable oxygen precursors for forming silicon oxide materials during step240include atomic oxygen (O), oxygen (O2), ozone (O3), water (H2O), hydrogen peroxide (H2O2), organic peroxides, alcohols, nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), plasmas thereof, radicals thereof, derivatives thereof, or combinations thereof. In one embodiment, an oxygen precursor may be formed by combining ozone and water to provide a strong oxidizing agent. The oxygen precursor generally contains hydroxyl radicals (OH) which have strong oxidizing power. The ozone concentration may vary relative to the water concentration. A molar ratio of ozone to water ratio may be within a range from about 0.01 to about 30, preferably, from about 0.03 to about 3, and more preferably, from about 0.1 to about 1. In one example, an energy beam derived from a UV source may be exposed to oxygen or an oxygen/water mixture to form an oxygen precursor containing ozone. In another embodiment, the energy delivery gas and/or the atmosphere within the chamber during the photoexcitation step includes oxygen and/or ozone.

In another embodiment, an alkoxysilane compound is used as the silicon precursors for forming silicon oxide materials during step240. The alkoxysilane may have the chemical formula (RO)nSiR′(4-n), wherein n=1, 2, 3, or 4, each R, independently, may be methyl, ethyl, propyl, butyl, or other alkyl group, and each R′, independently, may be hydrogen, a halogen group, methyl, ethyl, propyl, butyl, or other alkyl group. Examples of alkoxysilane compounds that may be used as silicon precursors include tetraethoxysilane ((EtO)4Si or TEOS), tetramethoxysilane ((MeO)4Si), tetrapropoxysilane ((PrO)4Si), tetraisopropoxysilane ((iPrO)4Si), tetrabutoxysilane ((BuO)4Si), triethoxysilane ((EtO)3SiH), diethoxysilane ((EtO)2SiH2), diethoxydimethylsilane ((EtO)2SiMe2), diethoxydiethylsilane ((EtO)2SiEt2), dimethoxydiethoxsilane ((MeO)2Si(OEt)2), derivatives thereof, or combinations thereof. In another embodiment, an alkoxysilane compound (e.g., TEOS) may be used as a source for both silicon and oxygen, instead of separate silicon and oxygen precursors, to form a silicon oxide material during step240.

In one example, a silicon oxide material may be deposited on substrate1122within process chamber1100during a deposition process at step240. In one embodiment, substrate1122may be exposed to a process gas containing a silicon precursor and an oxygen precursor during a CVD process. The silicon and oxygen precursors are generally provided from gas panel1136to interior volume1104of chamber body1102through flow control ring1142.

In one embodiment, at step240, the oxygen precursor and the silicon precursor may be introduced into process chamber or exposed to substrate1122by inlet port1134simultaneously, such as during a traditional CVD process or sequentially, such as during an ALD process. The ALD process may expose the substrate to at least two deposition gases, such that, the substrate is sequentially exposed to a silicon precursor and an oxygen precursor. Although one gas line1140is shown disposed between gas panel1136and inlet port1134, it is contemplated that the silicon precursor and the oxygen precursor are provided to process chamber1100in separate gas lines. The temperature may be controlled for each gas line.

A description of CVD and ALD processes and apparatuses that may be modified (e.g., incorporating a UV radiation source) and chemical precursors that may be useful for depositing silicon oxide materials are further disclosed in commonly assigned U.S. Pat. Nos. 6,869,838, 6,825,134, 6,905,939, and 6,924,191, and commonly assigned U.S. Ser. No. 09/964,075, filed Sep. 25, 2001, and published as US 2003-0059535, U.S. Ser. No. 10/624,763, filed Jul. 21, 2003, and published as US 2004-0018738, U.S. Ser. No. 10/794,707, filed Mar. 4, 2004, and published as US 2004-0175961, and U.S. Ser. No. 10/688,797, filed Oct. 17, 2003, and published as US 2004-0224089, which are all herein incorporated by reference in their entirety.

As the silicon precursor and the oxygen precursor may be combined in the process chamber, a silicon-containing material, such as a silicon oxide material, is formed on the substrate surface. In one embodiment, the silicon oxide material may be deposited at a rate within a range from about 10 Å/min to about 500 Å/min and is deposited to a thickness within a range from about 10 Å to about 1,000 Å. Silicon oxide materials may have a chemical formula such as SixOy, wherein an oxygen:silicon atomic ratio (Y/X) is about 2 or less, for example, SiO2. In one embodiment, the materials formed as described herein exhibits low hydrogen concentration and includes a small amount of carbon doping, which enhances boron retention in PMOS devices. In another embodiment, a halogen-free silicon precursor improves the wet etch rate.

A carrier gas may be provided during step240to control the partial pressure of the oxygen precursor and the silicon precursor. The total internal pressure of a single wafer process chamber may be at a pressure within a range from about 100 mTorr to about 740 Torr, preferably, from about 250 mTorr to about 100 Torr, and more preferably, from about 500 mTorr to about 50 Torr. In one example, the internal pressure of the process chamber is maintained at a pressure of about 10 Torr or less, preferably, about 5 Torr or less, and more preferably, about 1 Torr or less. In some embodiments, the carrier gas may be provided to control the partial pressure of the nitrogen precursor or the silicon precursor within a range from about 100 mTorr to about 1 Torr for batch processing systems. Examples of suitable carrier gases include nitrogen, hydrogen, argon, helium, forming gas, or combinations thereof.

The substrate, the silicon precursor, and/or the oxygen precursor may be exposed to an energy beam or a flux of energy generated by the photoexcitation system during the deposition process at step240. The use of the energy beam advantageously increases the deposition rate and improves surface diffusion or mobility of atoms within the silicon oxygen material to create active sites for incoming reactive species. In one embodiment, the beam has energy within a range from about 3.0 eV to about 9.84 eV. Also, the energy beam may have a wavelength within a range from about 126 nm to about 450 nm.

In one example, lamp1170of direct photoexcitation system1192and/or lamp1184of remote photoexcitation system1182provides an energy beam to supply the excitation energy of at least one of the silicon precursor or the oxygen precursor. The high deposition rate and the low deposition temperature produce a film having tunable properties with minimal parasitic side reactions. In one embodiment, the energy beam or flux may have a photon energy within a range from about 4.5 eV to about 9.84 eV. The substrate surface and the process gases may also be excited by lamps1170and1184.

In another embodiment, the substrate containing the silicon oxide material (formed in step240) is exposed to a post-deposition treatment process during step250. The post-deposition treatment process increases the substrate surface energy after deposition, which advantageously removes volatiles and/or other film contaminants (such as by reducing the hydrogen content) and/or anneals the deposited film. A lower concentration of hydrogen from the deposited material advantageously increases tensile stress of the film. At least one lamp (e.g., lamps1170or1184) may alternatively be utilized to energize an energy delivery gas which is exposed to the substrate to increase the surface energy of the substrate after deposition and to remove volatiles and/or other films.

Optionally, at step250, an energy delivery gas may be provided to interior volume1104of process chamber1100. Examples of suitable energy delivery gases include nitrogen, hydrogen, helium, argon, ozone, oxygen, hydrogen, water, hydroxyls, radicals thereof, plasma thereof, or combinations thereof. Examples provide that substrate1122is treated with an energy beam or flux of energy generated by photoexcitation system1144during step250. In one example, lamp1170of direct photoexcitation system1192provides an energy beam to supply the surface energy of substrate1122during step250. In another example for annealing the silicon oxide material, the energy beam or flux may have a photon energy within a range from about 3.53 eV to about 9.84 eV. Also, lamp1170may produce an energy beam having a wavelength within a range from about 126 nm to about 351 nm. Generally, lamp1170may be energized for a time period within a range from about 1 minute to about 10 minutes to facilitate post deposition treatment by photoexcitation.

In one example, volatile compounds or contaminants may be removed from the deposited film surface by exposing the substrate to an energy beam having a photon energy within a range from about 3.2 eV to about 4.5 eV is generated by lamp1170and/or lamp1184is utilized to dissociate silicon precursors and oxygen precursors within process chamber1100. Thus, excimer lamps, such as XeBr* (283 nm/4.41 eV), Br2* (289 nm/4.29 eV), XeCl* (308 nm/4.03 eV), I2* (342 nm/3.63 eV), XeF* (351 nm/3.53 eV) may be selected to remove hydrogen from the SiOxnetwork. It is contemplated that the rotational speed of substrate1122may be changed, for example, by increasing the rotation speed in step250relative to the preceding deposition step.

In another embodiment, the substrate may be removed from the process chamber and the process chamber is subsequently exposed to a chamber clean process during step260. The process chamber may be cleaned using a photoexcited cleaning agent. Alternatively, the cleaning agent may be provided from the remote plasma source1190. In one embodiment, the cleaning agent includes fluorine.

Examples provide that the cleaning agent may be photoexcited within process chamber1100using lamp1170, or remotely from process chamber1100using lamp1184. In one example, lamp1170may be used to maintain the excitation level of cleaning agents formed by RPS1190.

Process chamber1100may be cleaned during a chamber clean process to enhance deposition performance. For example, the chamber clean process may be used to remove contaminants contained on windows1174and1186, thereby minimizing transmission losses of the energy beam or flux traveling through window1174or1186and maximizing the energy transferred to the gases and surfaces. It is also contemplated that windows1174and1186may be cleaned using a photoexcited agent formed from RPS1190during the chamber clean process. Windows1174and1186may be cleaned with greater frequency than process chamber1100, for example, process chamber1100may be cleaned using RPS1190after processing a number of substrates while windows1174and1186are cleaned after processing each substrate.

The elemental composition of the silicon oxide material deposited during step240may be predetermined by controlling the concentration or flow rate of the chemical precursors, namely the silicon precursor and the oxygen precursor. Film properties may be tailored for specific applications by controlling the relative concentrations of Si, O, N, C, and H within the silicon oxide material. In one embodiment, the elemental concentrations of silicon, nitrogen, and hydrogen may be tuned by varying the range of the UV energy during or subsequent the deposition process. The film properties include wet etch rate, dry etch rate, stress, dielectric constant, and the like. For example, by reducing the hydrogen content, the deposited material may have a higher tensile stress. In another example, by reducing the carbon content, the deposited material may have a lower electrical resistance.

Silicon oxide materials deposited utilizing process200may be used throughout electronic features/devices due to several physical properties. The silicon oxide materials may be deposited as layers on a substrate to form electronic features, such as a MOSFET transistor (FIGS. 5A-5B), a bi-polar transistor (FIG. 6), or other silicon-containing layers. In another embodiment, silicon oxide materials deposited by process200may be used throughout photovoltaic cell applications, such as to form a solar cell.

Silicon Oxynitride Materials

FIG. 3depicts a flow diagram of process300for depositing a silicon oxynitride material, as described by embodiments herein. The substrate may be positioned within a process chamber (step310), optionally exposed to a pretreatment process (step320), and heated to a predetermined temperature (step330). Subsequently, a silicon oxynitride material may be deposited on the substrate (step340). The substrate may be optionally exposed to post-deposition treatment process (step350) and the process chamber may be optionally exposed to a chamber clean process (step360).

The substrate may be positioned within a process chamber during step310. The process chamber may be a single wafer chamber or a batch chamber containing multiple wafers or substrates (e.g., 25, 50, 100, or more). The substrate may be maintained in a fixed position, but preferably, is rotated by a support pedestal. Optionally, the substrate may be indexed during one or more steps of process300.

Process chamber1100, depicted inFIG. 7, may be used during process300to deposit silicon oxynitride materials on substrate1122as described by examples herein. In one example, substrate1122may be rotated on substrate support pedestal1124within process chamber1100at a rate of up to about 120 rpm. Alternatively, substrate1122may be positioned on substrate support pedestal1124and not rotated during the deposition process.

In one embodiment, the substrate is optionally exposed to at least one pretreatment process during step320. The substrate surface may contain native oxides that are removed during a pretreatment process. The substrate may be pretreated with an energy beam generated by direct photoexcitation system to remove the native oxides from the substrate surface prior to depositing a silicon oxynitride material during step340. A process gas may be exposed to the substrate during the pretreatment process. The process gas may contain argon, nitrogen, helium, hydrogen, forming gas, or combinations thereof. The pretreatment process may last for a time period within a range from about 2 minutes to about 10 minutes to facilitate native oxide removal during a photoexcitation process. Also, the substrate may be heated during step320to a temperature within a range from about 100° C. to about 800° C., preferably, from about 200° C. to about 600° C., and more preferably, from about 300° C. to about 500° C., to facilitate native oxide removal during process300.

Examples provide that substrate1122may be exposed to an energy beam produced by lamp1170during step320. Lamp1170may provide an energy beam having a photon energy within a range from about 2 eV to about 10 eV, for example, from about 3.2 eV to about 4.5 eV. In another example, lamp1170provides an energy beam of UV radiation having a wavelength within a range from about 126 nm to about 351 nm. Lamp1170may be energized for a period sufficient to remove oxides. The energization period is selected based upon the size and geometry of window1174(which corresponds to the exposed area of substrate1122) and the substrate rotation speed. In one embodiment, lamp1170is energized for a time period within a range from about 2 minutes to about 10 minutes to facilitate native oxide removal during a photoexcitation process. In one example, substrate1122may be heated to a temperature within a range from about 100° C. to about 800° C. during step320. In another example, substrate1122may be heated to a temperature within a range from about 300° C. to about 500° C. during step320, while lamp1170provides an energy beam having a photon energy within a range from about 2 eV to about 10 eV for a time period within a range from about 2 minutes to about 5 minutes to facilitate native oxide removal. In one example, the energy beam has a photon energy within a range from about 3.2 eV to about 4.5 eV for about 3 minutes.

In another embodiment, native oxide removal may be augmented by a photoexcitation process in the presence of a process gas containing an energy delivery gas during a pretreatment process at step320. The energy delivery gas may be neon, argon, krypton, xenon, argon bromide, argon chloride, krypton bromide, krypton chloride, krypton fluoride, xenon fluorides (e.g., XeF2), xenon chlorides, xenon bromides, fluorine, chlorine, bromine, excimers thereof, radicals thereof, derivatives thereof, or combinations thereof. In another embodiment, the energy delivery gas may contain ozone, oxygen, hydrogen, water, hydroxyls, radicals thereof, plasma thereof, or combinations thereof. In some embodiments, the process gas may also contain nitrogen gas (N2), hydrogen gas (H2), forming gas (e.g., N2/H2or Ar/H2) besides at least one energy delivery gas.

In one example, substrate1122may be exposed to a process gas containing an energy delivery gas by providing the process gas to interior volume1104of process chamber1100during step320. The energy delivery gas may be provided through flow control ring1142from gas panel1136. The proximately of the process gas to lamp1170compared to substrate1122readily excites the energy delivery gas therein. As the energy delivery gas de-excites and moves closer to substrate1122, the energy is efficiently transferred to the surface of substrate1122, thereby facilitating the removal of native oxides.

In another embodiment, native oxide removal may be augmented by a photoexcitation process in the presence of a process gas containing an organic vapor during the pretreatment process at step320. In one example, the substrate may be exposed to the process gas containing a cyclic aromatic hydrocarbon. The cyclic aromatic hydrocarbon may be in the presence of UV radiation. Monocyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons that are useful during a pretreatment process include quinone, hydroxyquinone (hydroquinone), anthracene, naphthalene, phenanthracene, derivatives thereof, or combinations thereof. In another example, the substrate may be exposed to the process gas containing other hydrocarbons, such as unsaturated hydrocarbons, including ethylene, acetylene (ethyne), propylene, alkyl derivatives, halogenated derivates, or combinations thereof. In another example, the organic vapor may contain alkane compounds during the pretreatment process at step320.

In one example, the UV radiation having a wavelength within a range from about 126 nm to about 351 nm may be generated by a lamp during step320. In another embodiment, polycyclic aromatic hydrocarbons may remove native oxides in the presence of UV radiation by reacting with oxygen atoms within the native oxides. In another embodiment, native oxides may be removed by exposing the substrate to quinone or hydroxyquinone while forming derivative products. The derivative product may be removed from the process chamber by a vacuum pumping process.

At step330, the substrate may be heated to a predetermined temperature during or subsequent to the pretreatment process. The substrate is heated prior to depositing the silicon oxynitride material at step340. The substrate may be heated by an embedded heating element within the substrate support, the energy beam (e.g., UV-source), or combinations thereof. Generally, the substrate is heated long enough to obtain the predetermined temperature, such as for a time period within a range from about 15 seconds to about 30 minutes, preferably, from about 30 seconds to about 20 minutes, and more preferably, from about 1 minute to about 10 minutes. In one embodiment, the substrate may be heated to a temperature within a range from about 200° C. to about 1,000° C., preferably, from about 400° C. to about 850° C., and more preferably, from about 550° C. to about 800° C. In another embodiment, the substrate may be heated to a temperature of less than about 550° C., preferably, less than about 450° C.

In one example, substrate1122may be heated to the predetermined temperature within process chamber1100. The predetermined temperature may be within a range from about 300° C. to about 500° C. Substrate1122may be heated by applying power from power source1116to the resistive heating element (i.e., the heater1120).

In one embodiment, a silicon oxynitride material is deposited on the substrate during a deposition process at step340. The silicon oxynitride material may be formed by exposing the substrate to at least one deposition gas during the deposition process. In one example, the deposition process is a CVD process having a deposition gas that may contain a silicon precursor and an oxygen precursor or a precursor containing both silicon and oxygen sources. Alternatively, the deposition process may be an ALD process having at least two deposition gases, such that, the substrate is sequentially exposed to a silicon precursor and an oxygen precursor. The deposition process may be a thermal process, a radical process, or a combination thereof. For example, the substrate may be exposed to a process gas in the presence of an energy beam generated by a direct photoexcitation system.

Examples of suitable oxygen precursors for forming silicon oxynitride materials during step340include atomic oxygen (O), oxygen (O2), ozone (O3), water (H2O), hydrogen peroxide (H2O2), organic peroxides, alcohols, nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), dinitrogen pentoxide (N2O5), plasmas thereof, radicals thereof, derivatives thereof, or combinations thereof. In one embodiment, an oxygen precursor may be formed by combining ozone and water to provide a strong oxidizing agent. The oxygen precursor generally contains hydroxyl radicals (OH) which have strong oxidizing power. The ozone concentration may vary relative to the water concentration. A molar ratio of ozone to water ratio may be within a range from about 0.01 to about 30, preferably, from about 0.03 to about 3, and more preferably, from about 0.1 to about 1. In one example, an energy beam derived from a UV source may be exposed to oxygen or an oxygen/water mixture to form an oxygen precursor containing ozone. In another embodiment, the energy delivery gas and/or the atmosphere within the chamber during the photoexcitation step includes oxygen and/or ozone.

Examples of suitable nitrogen precursors for forming silicon oxynitride materials during step340include ammonia (NH3), hydrazine (N2H4), organic amines, organic hydrazines, organic diazines (e.g., methyldiazine ((H3H)NNH)), silylazides, silylhydrazines, hydrogen azide (HN3), hydrogen cyanide (HCN), atomic nitrogen (N), nitrogen (N2), derivatives thereof, or combinations thereof. Organic amines as nitrogen precursors include RxNH3-x, where each R is independently an alkyl group or an aryl group and x is 1, 2, or 3. Examples of organic amines include trimethylamine ((CH3)3N), dimethylamine ((CH3)2NH), methylamine ((CH3)NH2)), triethylamine ((CH3CH2)3N), diethylamine ((CH3CH2)2NH), ethylamine ((CH3CH2)NH2)), tertbutylamine (((CH3)3C)NH2), derivatives thereof, or combinations thereof. Organic hydrazines as nitrogen precursors include RxN2H4-x, where each R is independently an alkyl group or an aryl group and x is 1, 2, 3, or 4. Examples of organic hydrazines include methylhydrazine ((CH3)N2H3), dimethylhydrazine ((CH3)2N2H2), ethylhydrazine ((CH3CH2)N2H3), diethylhydrazine ((CH3CH2)2N2H2), tertbutylhydrazine (((CH3)3C)N2H3), ditertbutylhydrazine (((CH3)3C)2N2H2), radicals thereof, plasmas thereof, derivatives thereof, or combinations thereof.

In one embodiment, the nitrogen precursors ideally contain a nitrogen-nitrogen single bond (i.e., N—N single bond) for decomposition of the nitrogen precursor at low temperatures. Additionally, when a silicon precursor and nitrogen precursor are used in the process gas mix, some amount of a nitrogen precursor may be included in the gas mix for additional control over the composition of the deposited layer during deposition. In a preferred example, the nitrogen precursor is ammonia. The nitrogen precursor generally disassociate at a temperature of less than about 500° C. with a high vapor pressure at room temperature. Examples of suitable nitrogen precursors and the respective vapor pressure include methylamine (vapor pressure of about 353 kPa at 25° C.), methylhydrazine (vapor pressure of about 66 kPa at 25° C.), and hydrocyanic acid (e.g., aqueous hydrogen cyanide solution)(vapor pressure of about 98.8 kPa at 25° C.).

In some embodiments, the silicon precursors for forming silicon oxynitride materials during step340include aminodisilanes, silylazides, or silylhydrazines having the chemical formulas:
R2NSi(R′2)Si(R′2)NR2(aminodisilanes),  (I)
R3SiN3(silylazides), or  (II)
R′3SiNRNR2(silylhydrazines).  (III)

In the above chemical formulas, R and R′ may be one or more functional groups independently selected from the group of a halogen, an organic group having one or more double bonds, an organic group having one or more triple bonds, an aliphatic alkyl group, a cyclical alkyl group, an aromatic group, an organosilyl group, an alkylamino group, or a cyclic group containing N or Si, or combinations thereof. Examples of suitable functional groups on silicon precursors include chloro (—Cl), methyl (—CH3), ethyl (—CH2CH3), isopropyl (—CH(CH3)2), tertbutyl (—C(CH3)3), trimethylsilyl (—Si(CH3)3), pyrrolidine, or combinations thereof.

Other examples of suitable silicon precursors for forming silicon oxynitride materials include silylazides R3.SiN3and silylhydrazine class of precursors R3SiNRNR2, linear and cyclic with any combination of R groups. The R groups may be H or any organic functional group such as methyl, ethyl, propyl, butyl, and the like (CXHY). The R groups attached to Si can optionally be another amino group NH2or NR2. One benefit of using a silicon-nitrogen precursor is that silicon and nitrogen are simultaneously delivered while avoiding the presence of chlorine to yield films with good step coverage and minimal pattern dependence (so-called pattern loading) without the undesirable ammonium chloride particle formation problematic to other precursors. Examples of specific silylazide compounds include trimethylsilylazide ((CH3)3SiN3)(available from United Chemical Technologies, located in Bristol, Pa.) and tris(dimethylamine)silylazide (((CH3)2N)3SiN3). An example of a specific silylhydrazine compound is 1,1-dimethyl-2-dimethylsilylhydrazine ((CH3)2HSiNHN(CH3)2). In another embodiment, the silicon-nitrogen precursor may be at least one of (R3Si)3N, (R3Si)2NN(SiR3)2and (R3Si)NN(SiR3), wherein each R is independently hydrogen or an alkyl, such as methyl, ethyl, propyl, butyl, phenyl, or combinations thereof. Examples of suitable silicon-nitrogen precursor include trisilylamine ((H3Si)3N), (H3Si)2NN(SiH3)2, (H3Si)NN(SiH3), or derivatives thereof.

In another embodiment, an alkoxysilane compound is used as the silicon precursors for forming silicon oxynitride materials during step340. The alkoxysilane may have the chemical formula (RO)nSiR′(4-n), wherein n=1, 2, 3, or 4, each R, independently, may be methyl, ethyl, propyl, butyl, or other alkyl group, and each R′, independently, may be hydrogen, a halogen group, methyl, ethyl, propyl, butyl, or other alkyl group. Examples of alkoxysilane compounds that may be used as silicon precursors include tetraethoxysilane ((EtO)4Si or TEOS), tetramethoxysilane ((MeO)4Si), tetrapropoxysilane ((PrO)4Si), tetraisopropoxysilane ((iPrO)4Si), tetrabutoxysilane ((BuO)4Si), triethoxysilane ((EtO)3SiH), diethoxysilane ((EtO)2SiH2), diethoxydimethylsilane ((EtO)2SiMe2), diethoxydiethylsilane ((EtO)2SiEt2), dimethoxydiethoxsilane ((MeO)2Si(OEt)2), derivatives thereof, or combinations thereof. In another embodiment, an alkoxysilane compound (e.g., TEOS) may be used as a source for both silicon and oxygen, instead of separate silicon and oxygen precursors, to form a silicon oxynitride material during step340.

In one embodiment to form the silicon oxynitride material, in step340, the silicon precursor, the oxygen precursor, and the nitrogen precursor may be combined in the process chamber or exposed to substrate1122by inlet port1134simultaneously, such as during a traditional CVD process or sequentially, such as during an ALD process. The ALD process may expose the substrate to the deposition gases, such that, the substrate is sequentially exposed to the silicon precursor, the oxygen precursor, and the nitrogen precursor to form the silicon oxynitride material. Although one gas line1140is shown disposed between gas panel1136and inlet port1134, it is contemplated that the silicon precursor, the oxygen precursor, and the nitrogen precursor are provided to process chamber1100in separate gas lines. The temperature may be controlled for each gas line.

In one example, a silicon oxynitride material may be deposited on substrate1122within process chamber1100during a deposition process at step340. In one embodiment, substrate1122may be exposed to a process gas containing a silicon precursor and an oxygen precursor during a CVD process to form a silicon oxide material that is subsequently exposed to a nitridization process to form a silicon oxynitride material. The silicon and oxygen precursors are generally provided from gas panel1136to interior volume1104of chamber body1102through flow control ring1142. In one example during step340, a silicon oxide material may be deposited on a substrate and exposed to a nitridation process that physically incorporates nitrogen atoms into the silicon oxide material to form a silicon oxynitride material. The nitridation process may include decoupled plasma nitridation (DPN), remote plasma nitridation, hot-wired induced atomic-N, and nitrogen incorporation during dielectric deposition (e.g., during CVD process). In a preferred example, radical nitrogen ions are formed by the UV photoexcitation as described herein. In another example, the nitridation process may be performed within a DPN chamber, such as the CENTURA® DPN chamber, available from Applied Materials, Inc., located in Santa Clara, Calif.

A description of CVD and ALD processes and apparatuses that may be modified (e.g., incorporating a UV radiation source) and chemical precursors that may be useful for depositing silicon oxynitride materials are further disclosed in commonly assigned U.S. Pat. Nos. 6,869,838 and 6,825,134, and commonly assigned U.S. Ser. No. 09/964,075, filed Sep. 25, 2001, and published as US 2003-0059535, U.S. Ser. No. 10/624,763, filed Jul. 21, 2003, and published as US 2004-0018738, U.S. Ser. No. 10/794,707, filed Mar. 4, 2004, and published as US 2004-0175961, and U.S. Ser. No. 10/688,797, filed Oct. 17, 2003, and published as US 2004-0224089, which are all herein incorporated by reference in their entirety.

A silicon oxynitride material may be formed by exposing the substrate to the silicon precursor, the oxygen precursor, and the nitrogen precursor are combined within a process chamber. In one embodiment, the silicon oxynitride material may be deposited at a rate within a range from about 10 Å/min to about 500 Å/min and is deposited to a thickness within a range from about 10 Å to about 1,000 Å. Silicon oxynitride materials may have a chemical formula such as SiOxNy, wherein X is within a range from about 0.01 to about 1.99 and Y is within a range from about 0.01 to about 1.32. In one example, the oxygen/nitrogen atomic ratio may be about 1 and the silicon oxynitride may have a chemical formula of about SiO0.8N0.8. In an example of an oxygen-rich silicon oxynitride, the oxygen/nitrogen atomic ratio is greater than 1 and the silicon oxynitride may have a chemical formula of about SiO1.6N0.5. In an example of a nitrogen-rich silicon oxynitride, the oxygen/nitrogen atomic ratio is less than 1 and the silicon oxynitride may have a chemical formula of about SiO0.5N1.0. In another embodiment, an alkoxysilane compound (e.g., TEOS) may be used as a source of both silicon and oxygen to form a silicon oxynitride material during step340.

A carrier gas may be provided during step340to control the partial pressure of the nitrogen precursor, the oxygen precursor, and the silicon precursor. The total internal pressure of a single wafer process chamber may be at a pressure within a range from about 100 mTorr to about 740 Torr, preferably, from about 250 mTorr to about 100 Torr, and more preferably, from about 500 mTorr to about 50 Torr. In one example, the internal pressure of the process chamber is maintained at a pressure of about 10 Torr or less, preferably, about 5 Torr or less, and more preferably, about 1 Torr or less. In some embodiments, the carrier gas may be provided to control the partial pressure of the nitrogen precursor or the silicon precursor within a range from about 100 mTorr to about 1 Torr for batch processing systems. Examples of suitable carrier gases include nitrogen, hydrogen, argon, helium, forming gas, or combinations thereof.

The substrate, the silicon precursor, the oxygen precursor, and/or the nitrogen precursor may be exposed to an energy beam or a flux of energy generated by the photoexcitation system during the deposition process at step340. The use of the energy beam advantageously increases the deposition rate and improves surface diffusion or mobility of atoms within the silicon oxynitride material to create active sites for incoming reactive species. In one embodiment, the energy beam has a photon energy within a range from about 3.0 eV to about 9.84 eV. Also, the energy beam may have a wavelength within a range from about 126 nm to about 450 nm.

In one example, lamp1170of direct photoexcitation system1192and/or lamp1184of remote photoexcitation system1182provides an energy beam to supply the excitation energy of at least one of the silicon precursor, the oxygen precursor, or the nitrogen precursor. The high deposition rate and the low deposition temperature produce a film having tunable properties with minimal parasitic side reactions. In one embodiment, the energy beam or flux may have a photon energy within a range from about 4.5 eV to about 9.84 eV. The substrate surface and the process gases may also be excited by lamps1170and1184.

In another embodiment, the substrate containing the silicon oxynitride material (formed in step340) is exposed to a post-deposition treatment process during step350. The post-deposition treatment process increases the substrate surface energy after deposition, which advantageously removes volatiles and/or other film contaminants (such as by reducing the hydrogen content) and/or anneals the deposited film. A lower concentration of hydrogen from the deposited material advantageously increases tensile stress of the film. At least one lamp (e.g., lamps1170or1184) may alternatively be utilized to energize an energy delivery gas which is exposed to the substrate to increase the surface energy of the substrate after deposition and to remove volatiles and/or other films.

In another embodiment of the photoexcitation step340, lamp1170of direct photoexcitation system1192and/or lamp1184of remote photoexcitation system1182provides an energy beam to supply the excitation energy of at least one of the silicon precursor and/or the nitrogen precursors, which advantageously increases the deposition rate without increasing the overall deposition temperature. The high rate, low temperature deposition reaction produces a film having tunable properties with minimal parasitic side reactions. In this embodiment, the energy beam or flux has a photon energy within a range from about 4.5 eV to about 9.84 eV. The surface of the substrate may also be excited by the lamp in addition to the process gases being energized.

Gas phase excitation and surface reactions will be controlled by UV excimer selection. For example, optical excitation of Si2H6may be achieved by using UV photons of hv>4.5 eV and hv>8 eV (λ<155 nm), respectively. Accordingly, intermediates of silanes—and NH3* (405 nm), NH2* (470.7 nm), NH* (336 nm)(with * indicating the compound in an excited state) enhances cross-linking bonds within the SiOxNynetwork, desirable for increasing film tensile stress.

In another embodiment, the substrate containing the silicon oxynitride material (formed in step340) is exposed to a post-deposition treatment process during step350. The post-deposition treatment process increase the substrate surface energy after deposition, which advantageously removes volatiles and/or other film contaminants (such as by reducing the hydrogen content) and/or to anneal the deposited film. The removal of hydrogen from the silicon oxynitride material from within the film advantageously increases film tensile stress. At least one lamp (e.g., lamps1170or1184) may alternatively be utilized to energize an energy delivery gas which is bought in contact with the substrate to increase the surface energy of the substrate after deposition and remove volatiles and/or other films.

Optionally, at step350, an energy delivery gas may be provided to interior volume1104of process chamber1100. Examples of suitable energy delivery gases include nitrogen, hydrogen, helium, argon, ozone, oxygen, hydrogen, water, hydroxyls, radicals thereof, plasma thereof, or combinations thereof. Examples provide that substrate1122is treated with an energy beam or flux of energy generated by photoexcitation system1144during step350. In one example, lamp1170of direct photoexcitation system1192provides an energy beam to supply the surface energy of substrate1122during step350. In another example for annealing the silicon oxynitride material, the energy beam or flux may have a photon energy within a range from about 3.53 eV to about 9.84 eV. Also, lamp1170may produce an energy beam having a wavelength within a range from about 126 nm to about 351 nm. Generally, lamp1170may be energized for a time period within a range from about 1 minute to about 10 minutes to facilitate post deposition treatment by photoexcitation.

In one example, volatile compounds or contaminants may be removed from the deposited film surface by exposing the substrate to an energy beam having a photon energy within a range from about 3.2 eV to about 4.5 eV is generated by lamp1170and/or lamp1184is utilized to dissociate silicon precursors, nitrogen precursors, and oxygen precursors within process chamber1100. Thus, excimer lamps, such as XeBr* (283 nm/4.41 eV), Br2* (289 nm/4.29 eV), XeCl* (308 nm/4.03 eV), I2* (342 nm/3.63 eV), XeF* (351 nm/3.53 eV) may be selected to remove hydrogen from the SiOxNynetwork. It is contemplated that the rotational speed of substrate1122may be changed, for example, by increasing the rotation speed in step350relative to the preceding deposition step.

In another embodiment, the substrate may be removed from the process chamber and the process chamber is subsequently exposed to a chamber clean process during step360. The process chamber may be cleaned using a photoexcited cleaning agent. Alternatively, the cleaning agent may be provided from the remote plasma source1190. In one embodiment, the cleaning agent includes fluorine.

Examples provide that the cleaning agent may be photoexcited within process chamber1100using lamp1170, or remotely from process chamber1100using lamp1184. In one example, lamp1170may be used to maintain the excitation level of cleaning agents formed by RPS1190.

Process chamber1100may be cleaned during a chamber clean process to enhance deposition performance. For example, the chamber clean process may be used to remove contaminants contained on windows1174and1186, thereby minimizing transmission losses of the energy beam or flux traveling through window1174or1186and maximizing the energy transferred to the gases and surfaces. It is also contemplated that windows1174and1186may be cleaned using a photoexcited agent formed from RPS1190during the chamber clean process. Windows1174and1186may be cleaned with greater frequency than process chamber1100, for example, process chamber1100may be cleaned using RPS1190after processing a number of substrates while windows1174and1186are cleaned after processing each substrate.

The elemental composition of the silicon oxynitride material deposited during step340may be predetermined by controlling the concentration or flow rate of the chemical precursors, namely the silicon precursor, the oxygen precursor, and the nitrogen precursor. Film properties may be tailored for specific applications by controlling the relative concentrations of Si, O, N, C, and H within the silicon oxynitride material. In one embodiment, the elemental concentrations of silicon, nitrogen, and hydrogen may be tuned by varying the range of the UV energy during or subsequent the deposition process. The film properties include wet etch rate, dry etch rate, stress, dielectric constant, and the like. For example, by reducing the hydrogen content, the deposited material may have a higher tensile stress. In another example, by reducing the carbon content, the deposited material may have a lower electrical resistance.

Additionally, when using N—Si—R or N—Si—Si—R type of precursors, the dissociation of the silicon-nitrogen precursor takes place at lower temperatures, thereby enabling lower temperature processing. The nitrogen precursors used herein may contain a carbon and hydrogen function group, which react with R or Si—R from N—Si—R or N—Si—Si—R in the silicon precursor, allow the R group to become dissociated and more easily removed than without reacting with nitrogen precursor. The nitrogen precursor provides nitrogen and carbon sources to the silicon oxynitride material. Thus, embodiments of the methods may advantageously facilitate low temperature processing, e.g., at temperatures of less than about 550° C.

Silicon oxynitride materials deposited utilizing process300may be used throughout electronic features/devices due to several physical properties. The silicon oxynitride materials may be deposited as layers on a substrate to form electronic features, such as a MOSFET transistor (FIGS. 5A-5B), a bi-polar transistor (FIG. 6), or other silicon-containing layers. In another embodiment, silicon oxynitride materials deposited by process300may be used throughout photovoltaic cell applications, such as to form a solar cell.

FIG. 4depicts a flow diagram of process400for depositing a silicon material (e.g., epitaxy, crystalline, microcrystalline, polysilicon, or amorphous), as described by embodiments herein. The substrate may be positioned within a process chamber (step410), optionally exposed to a pretreatment process (step420), and heated to a predetermined temperature (step430). Subsequently, a silicon material may be deposited on the substrate (step440). The substrate may be optionally exposed to post-deposition treatment process (step450) and the process chamber may be optionally exposed to a chamber clean process (step460).

The substrate may be positioned within a process chamber during step410. The process chamber may be a single wafer chamber or a batch chamber containing multiple wafers or substrates (e.g., 25, 50, 100, or more). The substrate may be maintained in a fixed position, but preferably, is rotated by a support pedestal. Optionally, the substrate may be indexed during one or more steps of process400.

Process chamber1100, depicted inFIG. 7, may be used during process400to deposit silicon materials on substrate1122as described by examples herein. In one example, substrate1122may be rotated on substrate support pedestal1124within process chamber1100at a rate of up to about 120 rpm. Alternatively, substrate1122may be positioned on substrate support pedestal1124and not rotated during the deposition process.

In one embodiment, the substrate is optionally exposed to at least one pretreatment process during step420. The substrate surface may contain native oxides that are removed during a pretreatment process. The substrate may be pretreated with an energy beam generated by direct photoexcitation system to remove the native oxides from the substrate surface prior to depositing a silicon material during step440. A process gas may be exposed to the substrate during the pretreatment process. The process gas may contain argon, nitrogen, helium, hydrogen, forming gas, or combinations thereof. The pretreatment process may last for a time period within a range from about 2 minutes to about 10 minutes to facilitate native oxide removal during a photoexcitation process. Also, the substrate may be heated during step420to a temperature within a range from about 100° C. to about 800° C., preferably, from about 200° C. to about 600° C., and more preferably, from about 300° C. to about 500° C., to facilitate native oxide removal during process400.

Examples provide that substrate1122may be exposed to an energy beam produced by lamp1170during step420. Lamp1170may provide an energy beam having a photon energy within a range from about 2 eV to about 10 eV, for example, from about 3.2 eV to about 4.5 eV for about 3 minutes. In another example, lamp1170provides an energy beam of UV radiation having a wavelength within a range from about 126 nm to about 351 nm. Lamp1170may be energized for a period sufficient to remove oxides. The energization period is selected based upon the size and geometry of window1174(which corresponds to the exposed area of substrate1122) and the substrate rotation speed. In one embodiment, lamp1170is energized for a time period within a range from about 2 minutes to about 10 minutes to facilitate native oxide removal during a photoexcitation process. In one example, substrate1122may be heated to a temperature within a range from about 100° C. to about 800° C. during step420. In another example, substrate1122may be heated to a temperature within a range from about 300° C. to about 500° C. during step420, while lamp1170provides an energy beam having a photon energy within a range from about 2 eV to about 10 eV for a time period within a range from about 2 minutes to about 5 minutes to facilitate native oxide removal. In one example, the energy beam has a photon energy within a range from about 3.2 eV to about 4.5 eV for about 3 minutes.

In another embodiment, native oxide removal may be augmented by a photoexcitation process in the presence of a process gas containing an energy delivery gas during a pretreatment process at step420. The energy delivery gas may be neon, argon, krypton, xenon, argon bromide, argon chloride, krypton bromide, krypton chloride, krypton fluoride, xenon fluorides (e.g., XeF2), xenon chlorides, xenon bromides, fluorine, chlorine, bromine, excimers thereof, radicals thereof, derivatives thereof, or combinations thereof. In some embodiments, the process gas may also contain nitrogen gas (N2), hydrogen gas (H2), forming gas (e.g., N2/H2or Ar/H2) besides at least one energy delivery gas.

In one example, substrate1122may be exposed to a process gas containing an energy delivery gas by providing the process gas to interior volume1104of process chamber1100during step420. The energy delivery gas may be provided through flow control ring1142from gas panel1136. The proximately of the process gas to lamp1170compared to substrate1122readily excites the energy delivery gas therein. As the energy delivery gas de-excites and moves closer to substrate1122, the energy is efficiently transferred to the surface of substrate1122, thereby facilitating the removal of native oxides.

In another embodiment, native oxide removal may be augmented by a photoexcitation process in the presence of a process gas containing an organic vapor during the pretreatment process at step420. In one example, the substrate may be exposed to the process gas containing a cyclic aromatic hydrocarbon. The cyclic aromatic hydrocarbon may be in the presence of UV radiation. Monocyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons that are useful during a pretreatment process include quinone, hydroxyquinone (hydroquinone), anthracene, naphthalene, phenanthracene, derivatives thereof, or combinations thereof. In another example, the substrate may be exposed to the process gas containing other hydrocarbons, such as unsaturated hydrocarbons, including ethylene, acetylene (ethyne), propylene, alkyl derivatives, halogenated derivates, or combinations thereof. In another example, the organic vapor may contain alkane compounds during the pretreatment process at step420.

In one example, the UV radiation having a wavelength within a range from about 126 nm to about 351 nm may be generated by a lamp during step420. In another embodiment, polycyclic aromatic hydrocarbons may remove native oxides in the presence of UV radiation by reacting with oxygen atoms within the native oxides. In another embodiment, native oxides may be removed by exposing the substrate to quinone or hydroxyquinone while forming derivative products. The derivative product may be removed from the process chamber by a vacuum pumping process.

At step430, the substrate may be heated to a predetermined temperature during or subsequent to the pretreatment process. The substrate is heated prior to depositing the silicon material at step440. The substrate may be heated by an embedded heating element within the substrate support, the energy beam (e.g., UV-source), or combinations thereof. Generally, the substrate is heated long enough to obtain the predetermined temperature, such as for a time period within a range from about 15 seconds to about 30 minutes, preferably, from about 30 seconds to about 20 minutes, and more preferably, from about 1 minute to about 10 minutes.

In one embodiment, the substrate may be heated to a temperature within a range from about 200° C. to about 1,000° C., preferably, from about 400° C. to about 850° C., and more preferably, from about 550° C. to about 800° C. In another embodiment, the substrate may be heated to a temperature of less than about 550° C., preferably, less than about 450° C. In one example, substrate1122may be heated to the predetermined temperature within process chamber1100. The predetermined temperature may be within a range from about 300° C. to about 500° C. Substrate1122may be heated by applying power from power source1116to the resistive heating element (i.e., the heater1120).

In one embodiment, a silicon material is deposited on the substrate during a deposition process at step440. The silicon material may be formed by exposing the substrate to at least one deposition gas during the deposition process. The silicon material may be deposited on the substrate surface, selectively or non-selectively (e.g., blanket), as an epitaxy layer, a crystalline layer, a microcrystalline layer, a polysilicon layer, an amorphous layer, dopant variants thereof, or combinations thereof.

In one example, the substrate is exposed to a deposition process gas containing a silicon precursor during a CVD process while using a UV energy source to non-selectively deposit an amorphous silicon material on the substrate surface. In another example, the substrate is exposed to a deposition process gas containing a silicon precursor and an etchant during a CVD process while using a UV energy source to selectively deposit an epitaxial silicon material on the substrate surface. In another example, the substrate is exposed to a deposition process gas containing a silicon precursor and a reducing agent during a CVD process while using a UV energy source to non-selectively deposit an amorphous silicon material on the substrate surface. In other examples, the substrate is exposed to a deposition process gas containing a silicon precursor and a UV energy source during a CVD process to deposit a crystalline silicon material, a microcrystalline silicon material, or a polycrystalline silicon material on the substrate surface.

Alternatively, the deposition process may be an ALD process having at least two deposition gases, such that, the substrate is sequentially exposed to a silicon precursor another reagent, such as a purge gas, an etchant, a reducing agent, a dopant reagent, or combinations thereof. The deposition process may be a thermal process, a radical process, or a combination thereof. For example, the substrate may be exposed to a process gas in the presence of an energy beam generated by a direct photoexcitation system.

In one example, a process utilizes UV-assisted to epitaxially grow or deposit a layer of silicon material on a substrate surface. The deposition gas used during the process contains a silicon precursor and may also contain at least one secondary elemental source, such as a germanium source and/or a carbon source. The germanium source may be added to the process chamber with the silicon precursor, etchant, reagent, or carrier gas to form the silicon material. Therefore, the silicon material may contain silicon, SiGe, SiC, SiGeC, doped variants thereof, or combinations thereof. Germanium and/or carbon may be added to the silicon material by including germanium source (e.g., germane) or a carbon source (e.g., methylsilane) during the deposition process. The silicon material may also contain dopants by including a boron source (e.g., diborane), an arsenic source (e.g., arsine), or a phosphorous source (e.g., phosphine) during or after the deposition process. The dopant may be included within the silicon precursor, etchant, reductant, or carrier gas to form a silicon material. Alternatively, the dopant may be added to the silicon material by exposing the substrate to an ion implantation process during or subsequent to the deposition process.

In some embodiments, the silicon precursors for forming silicon materials at step440include aminodisilanes, silylazides, or silylhydrazines having the chemical formulas:
R2NSi(R′2)Si(R′2)NR2(aminodisilanes),  (I)
R3SiN3(silylazides), or  (II)
R′3SiNRNR2(silylhydrazines).  (III)

In the above chemical formulas, R and R′ may be one or more functional groups independently selected from the group of a halogen, an organic group having one or more double bonds, an organic group having one or more triple bonds, an aliphatic alkyl group, a cyclical alkyl group, an aromatic group, an organosilyl group, an alkylamino group, or a cyclic group containing N or Si, or combinations thereof. Examples of suitable functional groups on silicon precursors include chloro (—Cl), methyl (—CH3), ethyl (—CH2CH3), isopropyl (—CH(CH3)2), tertbutyl (—C(CH3)3), trimethylsilyl (—Si(CH3)3), pyrrolidine, or combinations thereof. It is believed that many of the silicon precursors described herein may decompose or disassociate at a low temperature, such as about 550° C. or less.

Other examples of suitable silicon precursors include silylazides R3-SiN3and silylhydrazine class of precursors R3SiNRNR2, linear and cyclic with any combination of R groups. The R groups may be H or any organic functional group such as methyl, ethyl, propyl, butyl, and the like (CXHY). The R groups attached to Si can optionally be another amino group NH2or NR2. Examples of specific silylazide compounds include trimethylsilylazide ((CH3)3SiN3)(available from United Chemical Technologies, located in Bristol, Pa.) and tris(dimethylamine)silylazide (((CH3)2N)3SiN3). An example of a specific silylhydrazine compound is 1,1-dimethyl-2-dimethylsilylhydrazine ((CH3)2HSiNHN(CH3)2). In another embodiment, the silicon precursor may be at least one of (R3Si)3N, (R3Si)2NN(SiR3)2and (R3Si)NN(SiR3), wherein each R is independently hydrogen or an alkyl, such as methyl, ethyl, propyl, butyl, phenyl, or combinations thereof. Examples of suitable silicon precursors include trisilylamine ((H3Si)3N), (H3Si)2NN(SiH3)2, (H3Si)NN(SiH3), or derivatives thereof.

In one example, a silicon material may be deposited on substrate1122within process chamber1100during a deposition process at step440. In one embodiment, substrate1122may be exposed to a process gas containing a silicon precursor and an oxygen precursor during a CVD process. The silicon and oxygen precursors are generally provided from gas panel1136to interior volume1104of chamber body1102through flow control ring1142.

In one embodiment, in step440, the silicon precursor and at least another reagent may be introduced into process chamber or exposed to substrate1122by inlet port1134simultaneously, such as during a traditional CVD process or sequentially, such as during an ALD process. The ALD process may expose the substrate to at least two deposition gases, such that, the substrate is sequentially exposed to the silicon precursor and the other reagent (e.g., a purge gas, an etchant, a reducing agent, a dopant reagent, or combinations thereof). Although one gas line1140is shown disposed between gas panel1136and inlet port1134, it is contemplated that the silicon precursor and the other reagents are provided to process chamber1100in separate gas lines. The temperature may be controlled for each gas line.

The processes for depositing silicon materials may be conducted on fabrication equipment used for ALE, CVD, or ALD processes. A system that may be used to etch or deposit the silicon materials as described herein include the EPI CENTURA® system or the POLY GEN® system, both available from Applied Materials, Inc., located in Santa Clara, Calif. A process chamber useful to etch and deposit as described herein is further disclosed in commonly assigned U.S. Pat. No. 6,562,720, which is incorporated herein by reference in its entirety for the purpose of describing the apparatus. Other enabling apparatuses include batch furnaces and high-temperature furnaces.

As the silicon precursor and the reagent gases, if any, are combined in process chamber, a silicon-containing material, such as a silicon material, is formed on the substrate surface. In one embodiment, the silicon material may be deposited at a rate within a range from about 10 Å/min to about 500 Å/min and is deposited to a thickness within a range from about 10 Å to about 1,000 Å.

Throughout the application, the term “silicon material,” should be construed to include a composition within a layer or a film containing at least silicon and may contain germanium, carbon, boron, arsenic, phosphorous gallium, and/or aluminum. Other elements, such as metals, oxygen, nitrogen, halogens, or hydrogen may be incorporated within a silicon material usually with concentrations of about part per million (ppm). Compounds, alloys, or dopant derivatives of silicon materials may be represented by an abbreviation, such as Si for silicon, SiGe for silicon germanium, SiC for silicon carbon, and SiGeC for silicon germanium carbon. The abbreviations do not represent chemical equations with stoichiometrical relationships, nor represent any particular reduction/oxidation state of the silicon materials. Silicon materials or layers may be deposited or formed, selectively or non-selectively, as an epitaxy material or layer, a crystalline material or layer, a microcrystalline material or layer, a polysilicon material or layer, or an amorphous material or layer.

In one embodiment, the deposition gas used during step440may contain a silicon precursor and at least one secondary elemental source, such as a germanium source and/or a carbon source. The germanium source may be added to the process chamber with the silicon source and carrier gas to form a silicon material, such as a silicon germanium material. The germanium source is usually provided into the process chamber at a rate in the range from about 0.1 sccm to about 20 sccm, preferably from about 0.5 sccm to about 10 sccm, and more preferably from about 1 sccm to about 5 sccm, for example, about 2 sccm. Germanium sources useful to deposit silicon materials include germane (GeH4), higher germanes and organogermanes. Higher germanes include compounds with the empirical formula GexH(2x+2), such as digermane (Ge2H6), trigermane (Ge3H8) and tetragermane (Ge4H10), as well as others. Organogermanes include compounds such as methylgermane ((CH3)GeH3), dimethylgermane ((CH3)2GeH2) ethylgermane ((CH3CH2)GeH3), methyldigermane ((CH3)Ge2H5), dimethyldigermane ((CH3)2Ge2H4) and hexamethyldigermane ((CH3)6Ge2). Germanes and organogermane compounds have been found to be advantageous germanium sources and carbon sources in embodiments while incorporating germanium and carbon into the deposited silicon materials, namely SiGe and SiGeC compounds. The germanium concentration in the epitaxial layer is in the range from about 1 at % to about 30 at %, for example, about 20 at %. The germanium concentration may be graded within an epitaxial layer, preferably graded with a higher germanium concentration in the lower portion of the epitaxial layer than in the upper portion of the epitaxial layer.

Alternatively, a carbon source may be added during step440to the process chamber with the silicon source and carrier gas to form a silicon material, such as a silicon carbon material. A carbon source is usually provided into the process chamber at a rate in the range from about 0.1 sccm to about 20 sccm, preferably from about 0.5 sccm to about 10 sccm, and more preferably from about 1 sccm to about 5 sccm, for example, about 2 sccm. Carbon sources useful to deposit silicon materials include organosilanes, alkyls, alkenes and alkynes of ethyl, propyl and butyl. Such carbon sources include methylsilane (CH3SiH3), dimethylsilane ((CH3)2SiH2), ethylsilane (CH3CH2SiH3), methane (CH4), ethylene (C2H4), ethyne (C2H2), propane (C3H8), propene (C3H6), butyne (C4H6), as well as others. The carbon concentration of an epitaxial layer is in the range from about 200 ppm to about 5 at %, preferably from about 1 at % to about 3 at %, for example 1.5 at %. In one embodiment, the carbon concentration may be graded within an epitaxial layer, preferably graded with a higher carbon concentration in the lower portion of the epitaxial layer than in the upper portion of the epitaxial layer. Alternatively, a germanium source and a carbon source may both be added during step440into the process chamber with the silicon source and carrier gas to form a silicon material, such as a silicon germanium carbon material.

The deposition gas used during step440may further include at least one dopant compound to provide a source of elemental dopant, such as boron, arsenic, phosphorous, gallium or aluminum. Dopants provide the deposited silicon materials with various conductive characteristics, such as directional electron flow in a controlled and desired pathway required by the electronic device. Films of the silicon materials are doped with particular dopants to achieve the desired conductive characteristic. In one example, the silicon material is doped p-type, such as by using diborane to add boron at a concentration in the range from about 1015atoms/cm3to about 1021atoms/cm3. In one example, the p-type dopant has a concentration of at least 5×1019atoms/cm3. In another example, the p-type dopant is in the range from about 1×1020atoms/cm3to about 2.5×1021atoms/cm3. In another example, the silicon material is doped n-type, such as with phosphorous and/or arsenic to a concentration in the range from about 1015atoms/cm3to about 1021atoms/cm3.

A dopant source is usually provided into the process chamber during step440at a rate in the range from about 0.1 sccm to about 20 sccm, preferably from about 0.5 sccm to about 10 sccm, and more preferably from about 1 sccm to about 5 sccm, for example, about 2 sccm. Boron-containing dopants useful as a dopant source include boranes and organoboranes. Boranes include borane, diborane (B2H6), triborane, tetraborane and pentaborane, while alkylboranes include compounds with the empirical formula RxBH(3-x), where R=methyl, ethyl, propyl or butyl and x=1, 2 or 3. Alkylboranes include trimethylborane ((CH3)3B), dimethylborane ((CH3)2BH), triethylborane ((CH3CH2)3B) and diethylborane ((CH3CH2)2BH). Dopants may also include arsine (AsH3), phosphine (PH3) and alkylphosphines, such as with the empirical formula RxPH(3-x), where R=methyl, ethyl, propyl or butyl and x=1, 2 or 3. Alkylphosphines include trimethylphosphine ((CH3)3P), dimethylphosphine ((CH3)2PH), triethylphosphine ((CH3CH2)3P) and diethylphosphine ((CH3CH2)2PH). Aluminum and gallium dopant sources may include alkylated and/or halogenated derivates, such as described with the empirical formula RxMX(3-x), where M=Al or Ga, R=methyl, ethyl, propyl or butyl, X═Cl or F and x=0, 1, 2 or 3. Examples of aluminum and gallium dopant sources include trimethylaluminum (Me3Al), triethylaluminum (Et3Al), dimethylaluminumchloride (Me2AlCl), aluminum chloride (AlCl3), trimethylgallium (Me3Ga), triethylgallium (Et3Ga), dimethylgalliumchloride (Me2GaCl), gallium chloride (GaCl3), or derivatives thereof.

In one embodiment, a patterned substrate is loaded in to a process chamber and exposed to a deposition gas during a selective epitaxial process. Patterned substrates are substrates that include electronic features formed into or onto the substrate surface. The patterned substrate usually contains monocrystalline surfaces and at least one secondary surface that is non-monocrystalline, such as polycrystalline or amorphous surfaces. Monocrystalline surfaces include the bare crystalline substrate or a deposited single crystal layer usually made from a material such as silicon, silicon germanium or silicon carbon. Crystalline, microcrystalline, polycrystalline, or amorphous surfaces may include dielectric materials, such as oxides or nitrides, specifically silicon oxide or silicon nitride, as well as amorphous silicon surfaces.

A carrier gas may be provided during step440to control the partial pressure of the reagent gas and the silicon precursor. The total internal pressure of a single wafer process chamber may be at a pressure within a range from about 100 mTorr to about 740 Torr, preferably, from about 250 mTorr to about 100 Torr, and more preferably, from about 500 mTorr to about 50 Torr. In one example, the internal pressure of the process chamber is maintained at a pressure of about 10 Torr or less, preferably, about 5 Torr or less, and more preferably, about 1 Torr or less. In some embodiments, the carrier gas may be provided to control the partial pressure of the nitrogen precursor or the silicon precursor within a range from about 100 mTorr to about 1 Torr for batch processing systems. Examples of suitable carrier gases include nitrogen, hydrogen, argon, helium, forming gas, or combinations thereof.

The substrate, the silicon precursor, and/or reagent gas may be exposed to an energy beam or a flux of energy generated by the photoexcitation system during the deposition process at step440. The use of the energy beam advantageously increases the deposition rate and improves surface diffusion or mobility of atoms within the silicon-containing material to create active sites for incoming reactive species. In one embodiment, the energy beam has photon energy within a range from about 3.0 eV to about 9.84 eV. Also, the energy beam may have a wavelength within a range from about 126 nm to about 450 nm.

A carrier gas may be provided at step440to control the partial pressure of the reagent gas and/or the silicon precursor from a few mTorr to a few hundred Torr, and to control the total process pressure within a range from about 100 mTorr to about 740 Torr in single wafer chambers. In another embodiment, the internal pressure of the process chamber is maintained within a range from about 10 Torr to about 740 Torr. The carrier gas may be provided to control the partial pressure of the reagent gas or the silicon precursor within a range from about 100 mTorr to about 1 Torr for batch processing systems. Examples of suitable carrier gases include nitrogen, hydrogen, argon, helium, forming gas, or combinations thereof.

In one example, lamp1170of direct photoexcitation system1192and/or lamp1184of remote photoexcitation system1182provides an energy beam to supply the excitation energy of at least one of the silicon precursor or the reagent gas during step440. The high deposition rate and the low deposition temperature produce a film having tunable properties with minimal parasitic side reactions. In one embodiment, the energy beam or flux may have a photon energy within a range from about 4.5 eV to about 9.84 eV. The substrate surface and the process gases may also be excited by lamps1170and1184.

In another embodiment, the substrate containing the silicon material (formed in step440) is exposed to a post-deposition treatment process during step450. The post-deposition treatment process increases the substrate surface energy after deposition, which advantageously removes volatiles and/or other film contaminants (such as by reducing the hydrogen content) and/or anneals the deposited film. A lower concentration of hydrogen from the deposited material advantageously increases tensile stress of the film. At least one lamp (e.g., lamps1170or1184) may alternatively be utilized to energize an energy delivery gas which is exposed to the substrate to increase the surface energy of the substrate after deposition and to remove volatiles and/or other films.

Optionally, at step450, an energy delivery gas may be provided to interior volume1104of process chamber1100. Examples of suitable energy delivery gases include nitrogen, hydrogen, helium, argon, and combinations thereof. Examples provide that substrate1122is treated with an energy beam or flux of energy generated by photoexcitation system1144during step450. In one example, lamp1170of direct photoexcitation system1192provides an energy beam to supply the surface energy of substrate1122during step350. In another example for annealing the silicon material, the energy beam or flux may have a photon energy within a range from about 3.53 eV to about 9.84 eV. Also, lamp1170may produce an energy beam having a wavelength within a range from about 126 nm to about 351 nm. Generally, lamp1170may be energized for a time period within a range from about 1 minute to about 10 minutes to facilitate post deposition treatment by photoexcitation.

In one example, volatile compounds or contaminants may be removed from the deposited film surface by exposing the substrate to an energy beam having a photon energy within a range from about 3.2 eV to about 4.5 eV is generated by lamp1170and/or lamp1184is utilized to dissociate silicon precursors and the reagents within process chamber1100. Thus, excimer lamps, such as XeBr* (283 nm/4.41 eV), Br2* (289 nm/4.29 eV), XeCl* (308 nm/4.03 eV), I2* (342 nm/3.63 eV), XeF* (351 nm/3.53 eV) may be selected to remove hydrogen from the SiOxNynetwork. It is contemplated that the rotational speed of substrate1122may be changed, for example, by increasing the rotation speed in step450relative to the preceding deposition step.

In another embodiment, the substrate may be removed from the process chamber and the process chamber is subsequently exposed to a chamber clean process during step460. The process chamber may be cleaned using a photoexcited cleaning agent. Alternatively, the cleaning agent may be provided from the remote plasma source1190. In one embodiment, the cleaning agent includes fluorine. Examples provide that the cleaning agent may be photoexcited within process chamber1100using lamp1170, or remotely from process chamber1100using lamp1184. In one example, lamp1170may be used to maintain the excitation level of cleaning agents formed by RPS1190.

Process chamber1100may be cleaned during a chamber clean process to enhance deposition performance. For example, the chamber clean process may be used to remove contaminants contained on windows1174and1186, thereby minimizing transmission losses of the energy beam or flux traveling through window1174or1186and maximizing the energy transferred to the gases and surfaces. It is also contemplated that windows1174and1186may be cleaned using a photoexcited agent formed from RPS1190during the chamber clean process. Windows1174and1186may be cleaned with greater frequency than process chamber1100, for example, process chamber1100may be cleaned using RPS1190after processing a number of substrates while windows1174and1186are cleaned after processing each substrate.

The elemental composition of the silicon materials deposited during step440may be predetermined by controlling the concentration or flow rate of the chemical precursors, namely the silicon precursor and the reagent gas. Film properties may be tailored for specific applications by controlling the relative concentrations of Si, O, N, H, C, Ge, B, P, and As within the silicon material. In one embodiment, the elemental concentrations of silicon, nitrogen, and hydrogen may be tuned by varying the range of the UV energy during or subsequent the deposition process. The film properties include wet etch rate, dry etch rate, stress, dielectric constant, and the like. For example, by reducing the hydrogen content, the deposited material may have a higher tensile stress. In another example, by reducing the carbon content, the deposited material may have a lower electrical resistance.

Silicon materials deposited by process400may be used throughout electronic features/devices due to several physical properties. The silicon materials may be deposited as layers on a substrate to form electronic features, such as a MOSFET transistor (FIGS. 5A-5B), a bi-polar transistor (FIG. 6), or other silicon-containing layers. In another embodiment, silicon materials deposited by process400may be used throughout photovoltaic cell applications, such as to form a solar cell.

Embodiments, as described herein, provide processes that may be utilized to deposit silicon-containing materials during fabrication processes for Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and bipolar transistors, such as Bipolar device fabrication (e.g., base, emitter, collector, emitter contact), BiCMOS device fabrication (e.g., base, emitter, collector, emitter contact) and CMOS device fabrication (e.g., channel, source/drain, source/drain extension, elevated source/drain, substrate, strained silicon, silicon on insulator and contact plug). Other embodiments provide processes that may be utilized during gate fabrication processes, base contact fabrication processes, collector contact fabrication processes, emitter contact fabrication processes or elevated source/drain fabrication processes.

In some embodiments, silicon-containing materials may be deposited as various layers in MOSFET and bipolar transistors as depicted inFIGS. 5A-5Band6. The silicon-containing materials include silicon oxide, silicon nitride, silicon oxynitride, silicon (e.g., epitaxy, polysilicon, or amorphous), or other silicon-containing materials (e.g., SiGe, SiC, SiGeC, or doped variants thereof). For example,FIG. 5Ashows silicon-containing materials deposited within a MOSFET containing both recessed and elevated source/drains. Source/drain layer512is formed by ion implantation of substrate layer510. For pMOS, substrate layer510is doped n-type while source/drain layer512is doped p-type material. Silicon-containing layers513and514may be selectively and epitaxially grown on source/drain layer512or directly on substrate layer510by processes described herein. Silicon-containing layers513and514may contain silicon, silicon germanium, silicon carbon, silicon germanium carbon, dopant variants thereof, derivatives thereof, or combinations thereof. Gate barrier layer518bridges segmented silicon-containing layer513. Generally, gate barrier layer518may contain silicon oxide, silicon oxynitride, hafnium oxide, hafnium oxynitride, hafnium silicate, hafnium silicon oxynitride, derivatives thereof, or combinations thereof. Partially encompassing gate barrier layer518is a spacer516, which is usually an isolation material such as a nitride/oxide/nitride stack (e.g., Si3N4/SiO2/Si3N4). Alternatively, spacer516may be a homogeneous layer of a silicon nitride material, such as silicon nitride or silicon oxynitride deposited by the various methods described herein. Gate electrode layer522(e.g., polysilicon) may have a spacer516and off-set layers520disposed on either side. Off-set layers520may be composed of silicon nitride, silicon oxide, or silicon oxynitride deposited by the various processes described herein.

FIG. 5Bshows etch stop layer524for source/drain and gate contact aperture etch deposited over a MOSFET. Etch stop layer524may be composed of a silicon nitride material, such as silicon nitride, deposited by the various methods described herein. Pre-metal dielectric layer526(e.g., silicon oxide) is deposited on etch stop layer524and contains contact apertures528formed thereon.

In another embodiment,FIG. 6depicts substrate600having silicon-containing materials as several layers within a bipolar transistor using various processes as described in embodiments herein. Silicon-containing compound layer634is deposited on n-type collector layer632previously deposited on substrate layer630. The transistor further includes isolation layer633(e.g., SiO2, SiOxNyor Si3N4), contact layer636(e.g., heavily doped poly-Si), off-set layer638(e.g., Si3N4), and isolation layer640(e.g., SiO2, SiOxNyor Si3N4). Isolation layers633, isolation layer640, and off-set layer638may be independently deposited as a silicon nitride material, such as silicon oxynitride, silicon carbon nitride, and/or silicon nitride deposited by the various processes described herein. In one embodiment, the isolation layers633and640are silicon oxynitride and off-set layer638is silicon nitride.

Thus, a method for depositing a silicon-containing layer, such as silicon nitride, using photoexcitation has been provided. The method described above is suitable for device fabrication having small critical dimensions requiring low thermal budgets due to the use of deposition temperatures less than about 550° C., which advantageously facilitates robust circuit fabrication using sub 90 nm technology.

A “substrate” (e.g., substrate1122) or “substrate surface” as used herein refers to any substrate or material surface formed on a substrate upon which processes may be performed by embodiments described herein. For example, a substrate or a substrate surface may contain materials such as silicon, silicon-containing materials, silicon oxide, strained silicon, silicon on insulator (SOI), silicon nitride, doped silicon, silicon germanium, silicon germanium carbon, germanium, silicon carbon, gallium arsenide, glass, sapphire, fluorine-doped silicate glass (FSG), or carbon-doped silicon oxides, such as SiOxCy, for example, BLACK DIAMOND® low-k dielectric, available from Applied Materials, Inc., located in Santa Clara, Calif. A substrate surface may also include dielectric materials such as silicon dioxide, silicon nitride, silicon oxynitride and/or carbon doped silicon oxides. Substrates may have various dimensions, such as 200 mm or 300 mm diameter round wafers, as well as, rectangular or square panes. Embodiments of the processes described herein form or deposit silicon-containing materials on many substrates and substrate surfaces. Substrates on which embodiments of the invention may be useful include, but are not limited to semiconductor wafers, such as crystalline silicon (e.g., Si<100> or Si<111>), silicon oxide, strained silicon, silicon germanium, doped or undoped polysilicon, doped or undoped silicon wafers silicon nitride and patterned or non-patterned wafers. Optionally, substrate1122may be pretreated prior to the deposition of a silicon-containing material by a polishing process, an etching process, a reducing process, an oxidizing process, a halogenation process, a hydroxylation process, an annealing process, a plasma process, a UV process, or combination thereof.

Throughout the application, the terms “silicon-containing” materials, compounds, films, or layers should be construed to include a composition containing at least silicon and may contain germanium, carbon, boron, arsenic, phosphorous gallium and/or aluminum. Other elements, such as metals, halogens or hydrogen may be incorporated within a silicon-containing material, compound, film or layer, usually with concentrations of about part per million (ppm). Compounds or alloys of silicon-containing materials may be represented by an abbreviation, such as Si for silicon, SiGe, for silicon germanium, SiC for silicon carbon and SiGeC for silicon germanium carbon. The abbreviations do not represent chemical equations with stoichiometrical relationships, nor represent any particular reduction/oxidation state of the silicon-containing materials. Silicon-containing materials, compounds, films or layers may include substrates or substrate surfaces.

Hardware

In the embodiment ofFIG. 7, process chamber1100includes a chamber body1102coupled to pumping system1138, a controller1146, at least one photoexcitation system1144and a gas panel1136. Chamber body1102has walls1106, a bottom1108, and a lid1110that define an internal volume1104. The walls1106of the process body1102may be thermally regulated. In one embodiment, a plurality of conduits1112are disposed in the walls1106and are configured to circulate a heat transfer fluid that regulates the temperature of chamber body1102. The walls1106additionally include a substrate access port1128configured to facilitate entry and egress of a workpiece, such as substrate1122, from process chamber1100.

Substrate support pedestal1124is disposed in internal volume1104of chamber body1102and supports substrate1122during processing. Substrate support pedestal1124includes heater1120configured to regulate the temperature of substrate1122and/or heat interior volume1104of process chamber1100. In the embodiment depicted inFIG. 7, heater1120is a resistive heating element coupled to a power source1116and is capable of heating the substrate to a temperature of about 550° C. or higher.

Pedestal lift assembly1130is coupled to substrate support pedestal1124and is configured to control the elevation of substrate support pedestal1124between an elevated processing position (as shown inFIG. 7) and a lowered position that facilitates access to substrate1122disposed on substrate support pedestal1124through the substrate access port1128. The pedestal lift assembly1130is sealingly coupled to bottom1108of chamber body1102by a flexible bellows1132. Optionally, the pedestal lift assembly1130may be configured to rotate substrate support pedestal1124during processing. Pedestal lift assembly1130and similar assemblies that may be used by embodiments described herein is disclosed in commonly assigned U.S. Ser. No. 11/147,938, entitled “Rotating Substrate Support and the Methods of Use,” and filed Jun. 8, 2005, which is herein incorporated by reference in its entirety. The pedestal lift assembly1130may be configured to rotate substrate support pedestal1124continuously at a constant rate, rotate substrate support pedestal1124continuously at different rates, or to index substrate support pedestal1124.

Gas panel1136is coupled to process chamber1100and is configured to provide process precursors and chemicals, in liquid and/or gaseous form, and other gases to interior volume1104of chamber body1102. In the embodiment depicted inFIG. 7, gas panel1136is coupled by gas line1140, which is used to transfer process chemical or mixed process gases or vapors from liquid injector generated from a selected liquid chemical source, to inlet port1134formed in lid1110of chamber body1102. It is contemplated that inlet port1134may be formed through one or more other locations of chamber body1102.

Flow control ring1142is disposed in the process body1102and is coupled to port134. Flow control ring1142is configured to direct gas flow1180(represented by arrows) of process gas across substrate1122supported on substrate support pedestal1124. Flow control ring1142is additionally configured to maintain a flow of purge gas, provided to a portion of interior volume1104defined below substrate support pedestal1124from purge gas source1154, flowing upwards around the lower edge of substrate support pedestal1124, and thereby preventing deposition gases from entering the region below substrate support pedestal1124. Gases exiting flow control ring1142are generally collected in pumping channel1156prior to removal from process chamber1100through pumping port1126by pumping system1138. Pumping system1138generally includes a throttle valve and one or more pumps arranged to control the pressure within internal volume1104of process chamber1100. Flow control ring1142is further detailed below with reference to FIGS.8and9A-B.

Lift pins1114(of which one is shown inFIG. 7) are provided to separate substrate1122from the upper surface of substrate support pedestal1124to facilitate substrate hand-off with a robot (not shown) entering the chamber body through access port1128. In the embodiment depicted inFIG. 7, lift plate1118is disposed below substrate support pedestal1124and arranged such that as substrate support pedestal1124is lowered, lift pins1114come in contact with lift plate1118before substrate support pedestal1124has completed its downward travel. Lift plate1118supports lift pins1114as substrate support pedestal1124continues downward, causing lift pins1114to extend from the upper surface of the pedestal. The position of lift plate1118and/or the length of lift pins1114are configured such that substrate1122becomes spaced-apart from substrate support pedestal1124and generally aligned with access port1128when substrate support pedestal1124is in the lowered position.

Photoexcitation system1144is positioned to provide energy to at least one of the process gases or the surface of substrate1122. In one embodiment, photoexcitation system1144includes at least one of remote photoexcitation system1182or a direct photoexcitation system1192. Although the embodiment depicted inFIG. 7includes both remote photoexcitation system1182and a direct photoexcitation system1192, it is contemplated that process chamber1100may optionally be configured with a single photoexcitation system (i.e., either the system1182or1192). The energy from photoexcitation system1144may be utilized in a number of ways. For example, the energy may be utilized to remove native oxides from the surface of substrate1122prior to deposition, to increase the energy of the process gases, thus, increasing deposition rates while reducing deposition temperatures, and to increase the energy level of the deposited materials, thereby increasing deposition rates, allowing greater mobility of atoms within the film and assisting in the reduction of hydrogen or other volatile materials within the film.

In one embodiment, direct photoexcitation system1192generally includes at least one lamp1170positioned to deliver a beam or flux of energy to substrate surface. The flux of energy can be delivered in a continuous mode or in a pulsed mode. Lamp1170may additionally be utilized to energize process and/or cleaning gases.

Direct photoexcitation system1192is positioned above one or more windows1174disposed in lid1110, such that energy emitted from photoexcitation system1144may be directed into internal volume1104of process chamber1100. Power source1172is coupled to lamp1170and selectively controls the energy emitted from the lamp within a range from about 1 eV to about 10 eV, and at a frequency within a range from about 100 nm to about 480 nm. In one embodiment, lamp1170is an excimer lamp.

In another embodiment, lamp1170may include one or more lamps that generate energy at different wavelengths. Thus, different lamps may be energized at different times during a process to produce a desired energy level. Lamps1170may also be pulsed to produce the desired energy level. The energy at different wavelengths may be produced simultaneously, or at different times during processing.

Window1174is generally sealed to lid1110in a manner that prevents vacuum leakage. Window1174is fabricated from a material transmissive to the energy emitted from lamp1170while being substantially compatible with process chemistries. In one embodiment, window1174is fabricated from sapphire or magnesium fluoride.

To protect window1174from deposition, baffle plate1160is provided below lid1110to direct a blanket of purge gas between window1174and substrate1122disposed on substrate support pedestal1124. Baffle plate1160includes an aperture that is aligned with window1174to allow the beam or flux of energy from lamp1170to impinge upon the substrate and/or gases within internal volume1104of process chamber1100. A shutter plate can be added below or above window1174that can be open or shut to achieve a pulsing of the beam on the surface of the substrate. Purge gas source1178is coupled to purge gas inlet1164formed through process chamber1100and provides a purge gas to the region between lid1110and baffle plate1160. Additional details of direct photoexcitation system1192, lid1110, window1174and baffle plate1160are described further below with reference toFIGS. 10-14.

FIGS.8and9A-9B are sectional and bottom views of one embodiment of flow control ring1142. Flow control ring1142has outer side1202, inner wall1204, top1206, and bottom1208. Flow control ring1142may be fabricated from a material compatible with the process conditions, such as aluminum, anodized aluminum, steel, stainless steel, or derivatives thereof. In the embodiment depicted in FIGS.8and9A-9B, flow control ring1142is shown fabricated from main body1244having insert1246coupled thereto. It is contemplated that flow control ring1142may alternatively be fabricated as a since piece member, be assembled into a unitary body, or contain multiple sections held together within process chamber1100.

Three plenums are defined within flow control ring1142. An upper portion1240of flow control ring1142includes inlet plenum1210and outlet plenum1212. Inlet plenum1210is separated from outlet plenum1212by wall1230. In one embodiment, wall1230spaces inlet plenum1210and outlet plenum1212to opposite sides of flow control ring1142.

Pumping plenum1214is disposed in lower portion1242of flow control ring1142and is separated from the plenums1210and1212by interior wall1228. Pumping plenum1214is substantially annular, circumscribing inner wall1204of flow control ring1142.

One or more inlet ports1216are formed through inner wall1204of flow control ring1142. In the embodiment depicted inFIGS. 8 and 9A, a plurality of inlet ports1216are formed through inside diameter wall1232of insert1246that forms part of inner wall1204of flow control ring1142. Inlet ports1216fluidly couple inlet plenum1210to internal volume1104of process chamber1100. Thus, gases provided through inlet port1134formed in lid1110(shown in phantom inFIG. 8) may be delivered from gas panel1136to interior volume1104of process chamber1100through flow control ring1142.

Outlet plenum1212is formed in flow control ring1142opposite inlet plenum1210. One or more paths of gas flow1180pass through upper outlet port1218positioned within inner wall1204of flow control ring1142to allow gases within interior volume1104of process chamber1100to enter outlet plenum1212. Upper outlet port1218may be a hole, slot, aperture, or other flow conduit suitable for allowing a gas flow to enter flow control ring1142. In one example as depicted inFIGS. 8 and 9A, upper outlet port1218is an annular notch formed in inner wall1204at top1206of flow control ring1142.

FIG. 8depicts gas flow1180of the process gas entering interior volume1104through inlet ports1216are drawn back into outlet plenum1212through upper outlet port1218, thereby creating a cross-flow (e.g., flow from one edge to the edge on the opposing side of the substrate) of process gases laterally across substrate1122in a non-radial manner. The size, size variation, geometry and distribution of inlet ports1216and upper outlet port1218are selected to obtain desired gas flow distribution across the surface of substrate1122.

Unused process gas and reaction by-products flow are routed from outlet plenum1212to pumping plenum1214through at least one transfer hole1220formed through the interior wall1228. Again, the size, number of holes and geometry of transfer hole1220provide control of gas flow1180. In the embodiment depicted in FIGS.8and9A-9B, transfer hole1220is an annular slot.

A plurality of lower outlet ports1226are formed through inner wall1204to allow purge gas (entering process chamber1100below substrate support pedestal1124, as shown inFIG. 7) to enter pumping plenum1214. Gases entering pumping plenum1214through lower outlet ports1226and transfer hole1220are drawn into pumping channel1156and exhausted from process chamber1100by pumping system1138. The size, size variation, geometry, multiplicity, and distribution of transfer hole1220, lower outlet ports1226, or other exhaust ports are selected to obtain desired gas flow into pumping plenum1214, which assists in tuning the flow of process gases across the surface of the substrate and preventing process gases from contaminating the region below substrate support pedestal1124.

FIG. 14is a sectional view of one embodiment of direct photoexcitation system1192mounted on lid1110. Direct photoexcitation system1192generally includes housing1402that retains lamp1170in an internal cavity1404and mounting frame1406that secures a plurality of windows1174. Housing1402may be fabricated from aluminum or other suitable material and is coupled to lid1110in a leak-tight manner. In one embodiment, mounting frame1406is sealed to the lid by a first o-ring, while housing1402is sealed to mounting frame1406by a second o-ring. It is contemplated that either o-ring may be replaced by a gasket or other sealing material. Mounting frame1406and housing1402may be secured to the lid by a fastener or other suitable method.

Interior walls1408of housing1402defining cavity1404are coated with a reflective material to minimize parasitic absorption of energy generated by lamp1170, thereby increasing the amount of energy directed through window1174. In one example, interior walls1408are coated with nickel as a reflective material.

Interior walls1408are shaped to enhance the direction of light or photons through window1174. In one embodiment, a flux or energy beam1410(represented by arrows) produced by lamp1170is directed substantially normal to the surface of substrate1122(shown in phantom). It is contemplated that it may be desirable to direct energy beam1410at other angles of incidence to the substrate. For example, as illustrated in the schematic diagram ofFIG. 11A, reflector1510positioned proximate lamp1170may be configured to direct energy beam1410at an acute angle relative to substrate1122. In another example depicted inFIG. 11B, optics1520, such as a collimator lens1522and prism1524, may be utilized to set the angle of incidence of energy beam1410. It is also contemplated that a microactuator may be coupled to the prism1524to select the angle of incidence within a range from about 45° to about 90°, as shown by the dashed arrows. As additionally shown inFIG. 11A, shutter1550may be utilized to pulse or selectively allow energy beam1410to enter internal volume1104of process chamber1100when desired.

To prevent direct photoexcitation system1192from overheating and to maintain consistent performance, direct photoexcitation system1192may be temperature controlled. For example, the purge gas source1178may be coupled to cavity1404of housing1402by inlet passage1412. Inlet passage1412injects a heat transfer fluid, such as nitrogen to remove heat generated by lamp1170from housing1402. The heat transfer fluid is removed from cavity1404through outlet passage1414.

Thermocouple1416is positioned to provide controller1146with a metric indicative of the temperature of the heat transfer fluid, window, lamp or other portion of direct photoexcitation system1192so that the temperature of the lamp and/or seals of direct photoexcitation system1192may be maintained within operating temperature ranges. For example, utilizing temperature information provided by thermocouple1416, at least one of the power provided to lamp1170, the temperature and/or the flow rate of the heat transfer fluid circulated through housing1402may be adjusted to maintain lamp1170from overheating or exceeding the operational temperature of window1174.

FIG. 12depicts an exploded view of one embodiment of frame assembly1600utilized to couple window1174to mounting frame1406. Mounting frame1406includes flange1612having gland1630formed therein that accepts a seal utilized to provide the leak-tight seal between mounting frame1406and lid1110as described above.

Frame assembly1600generally includes window insert mount1602and window frame1604. Window insert mount1602is disposed in pocket1614framed in mounting frame1406. Window insert mount1602includes flange1620and base1624. Flange1620of window insert mount1602extends outward from base1624and includes a gland1622. Mount seal1606, such as an o-ring, is disposed in gland1622and provides a seal between window insert mount1602and base1616of mounting frame1406. Compression of mount seal1606is maintained by fasteners (not shown) coupling window insert mount1602to mounting frame1406.

Base1624is generally an elongated rectangle that includes a plurality of apertures1626for allowing passage of the energy beam or flux through the frame assembly. In the embodiment depicted inFIG. 12, base1624is disposed in rectangular aperture1618formed in base1616of mounting frame1406.

One or more lamps are secured between window insert mount1602and window frame1604. In the embodiment depicted inFIG. 12, four windows1174are clamped between window insert mount1602and window frame1604. Upper window seal1608is disposed in gland1632formed in window frame1604and provides a seal between window1174and window frame1604. A lower window seal1610is disposed in a gland1628formed in window insert mount1602and provides a seal between window1174and window insert mount1602. Compression of the upper and lower window seals1608,1610is maintained by fasteners (not shown) coupling window frame1604to window insert mount1602.

The seals between window insert mount1602and mounting frame1406, and between window1174and window insert mount1602and mounting frame1406, do not need to be air-tight. Since nitrogen-filled cavity1404of housing1402is maintained at a higher pressure than interior volume1104of process chamber1100, slight leakage of nitrogen into the area of process chamber1100between baffle plate1160and lid1110is acceptable as being innocuous to processes performed in process chamber1100.

Once windows1174are clamped in place within frame assembly1600, apertures1634formed through window frame1604and apertures1626formed through window insert mount1602align with window1174and aperture1162of baffle plate1160to allow the beam or flux of energy generated by lamp1170to enter the chamber.

To provide process control feedback, direct photoexcitation system1192may include one or more sensors that provide a metric indicative of lamp performance. This metric advantageously allows processors to selectively control process attributes to obtain films having desired properties and deposition rates.

FIG. 14is a sectional view of direct photoexcitation system1192taken along section line14-14ofFIG. 10illustrating sensors utilized to provide metric indicative of lamp performance. In the embodiment depicted inFIG. 14, first sensor1802is disposed through housing1402and extends between the lamps1170, through the frame assembly1600and into interior volume1104of process chamber1100. First sensor1802may utilize a compression fitting1808or suitable seal to prevent gas leakage from housing1402. First sensor1802is generally capable of providing a metric indicative of the energy incident on substrate1122. In one embodiment, first sensor1802is a flux sensor. One suitable flux sensor that may be adapted to benefit from the invention is available from Hamamatsu Corporation, located in Hamamatsu City, Japan. As first sensor1802is positioned below window1174and relatively close to substrate1122, the energy levels measured are indicative of the actual energy reaching the substrate, and accounts for parasitic energy losses such as energy absorbed by window1174and gases within housing1402and process chamber1100. Thus, if a predetermined energy level is desired at the substrate surface, lamp1170(or other processing attribute) may be adjusted in-situ to obtain and/or maintain a desired film characteristic.

Second sensor1804may be utilized to detect energy levels in housing1402. Second sensor1804is sealed to housing1402as described above with reference to first sensor1802. Second sensor1804is generally capable of providing a metric indicative of the energy generated by lamp1170within housing1402. In one embodiment, second sensor1804is a flux sensor. Information obtained from first sensor1802may be compared with the information obtained from second sensor1804to determine parasitic energy losses as the energy generated by the lamp acts upon objects, such as the window, gases and the substrate, positioned within the chamber. Through design experiments, for example by comparing data from the sensors with and without process gas flows, the energy incident on substrate1122and absorbed by the process gases may be determined and utilized to control film properties during deposition.

Returning toFIG. 10, curtain1418of inert gas is provided across lower surface1420of window1174to further maintain the performance of direct photoexcitation system1192. Curtain1418is created by flowing nitrogen (or other inert gas) into purge plenum1430defined between body1440of baffle plate1160and lid1110.

Referring additionally to the top and bottom perspective views of the baffle plate1160depicted inFIGS. 13A-13B, purge plenum1430is bounded by lip1434extending from body1440to lid1110and weir1423. Body1440provides a physical separation between lid1110and the process gases flowing into process chamber1100. Body1440typically has no openings or apertures between first side1710of body1440disposed over inlet ports1216and aperture1162to prevent process gases from contacting window1174.

Lip1434extends further from body1440than weir1423. Thus, gases flowed into purge plenum1430are substantially confined in purge plenum1430and forced over orifice1436defined between weir1423and lid1110along flow path1708(represented by arrow). Lip1434includes a release port1702formed on a second side1712of baffle plate1160opposite first side1710that allows the purge gases to escape from behind baffle plate1160and enter flow control ring1142through the outlet plenum. In the embodiment depicted inFIG. 13A, the release port1702is a notch formed in the distal end of lip1434.

Orifice1436(and weir1432that defines orifice1436) extends parallel to and spaced apart from window1174. The pressure drop across orifice1436, along with the pressure within the interior volume and purge plenum1430, are selected to control the flow of curtain1418in the direction substantially parallel to gas flow1180of the process gas while maintaining substantially uniform flow across weir1423so that window1174is protected by curtain1418. In one embodiment, the velocity of curtain1418is substantially matched to the process gas flow to minimize turbulent mixing of the gases that may bring some process gases in contact with window1174.

To ensure uniform spacing between baffle plate1160and lid1110, a plurality of stand-offs or bosses1704,1706extend from baffle plate1160. The first set of bosses1704extend from weir1432, while the second set of bosses706extend from body1440between the region of body1440defined between aperture1162and second side1712. Bosses1704additionally provide a structure through which flow path1708is formed. Flow path1708extends through baffle plate1160and accommodates fasteners (not shown) utilized to secure baffle plate1160to lid1110. In the embodiment depicted inFIG. 13B, each flow path1708through bosses1704,1706is counter-bored or counter-sunk on the pedestal side of baffle plate1160to recess the head of the fastener.

Returning toFIG. 7, remote photoexcitation system1182may be disposed between gas panel1136and inlet port1134. Remote photoexcitation system1182may be utilized to energize the gases entering process chamber1100from gas panel1136. The energized gases may be utilized for treating the substrate, cleaning the chamber, promoting a film deposition and/or controlling characteristics of the deposited film.

In one embodiment, remote photoexcitation system1182includes lamp1184disposed in housing1194. Lamp1184is coupled to the power source1172, or other suitable source. Lamp1184generally produces energy within a range from about 1 eV to about 10 eV, and at a frequency within a range from about 100 nm to about 480 nm. In one embodiment, lamp1184is an excimer lamp.

In another embodiment, lamp1184may include one or more lamps that generate energy at different wavelengths. Thus, different lamps may be energized at different times during a process to produce a desired energy level. Thus, one lamp may be utilized to energize a selected gas and/or surface while another lamp may be utilized to energize a different gas and/or achieve a desired effect on the deposited film.

In another example, a first wavelength may be utilized to energize a first precursor or a surface, followed by a second wavelength utilized to energize a second precursor or the surface. In such a manner, monolayer deposition may be achieved. Other examples suitable for monolayer deposition through atomic and/or cyclic deposition techniques includes, but is not limited to, photoenergization of only one of the two precursors, photoenergization of a purge gas flowed into the chamber between injection of at least one of or after both of the precursors, photoenergization of the substrate surface between injection of at least one of or after both of the precursors, or combinations thereof among others process sequences.

Gas from gas panel1136flowing through passage1188formed in housing1194may optionally be separated from lamp1184by window1186. Window1186may be fabricated from a suitable transmissive material, such as magnesium fluoride.

Remote plasma source (RPS)1190may be coupled to process chamber1100. RPS1190generally provides a reactive cleaning agent, such as disassociated fluorine, that removes deposition and other process byproducts from the chamber components. In the embodiment depicted inFIG. 7, RPS1190is coupled to inlet port1134such that the inlet side of flow control ring1142is cleaned. Optionally, RPS1190may be coupled to purge gas inlet1164so that the cleaning agent may more effectively clean window1174.

Alternatively, fluorine or other suitable cleaning agent may be provided to the purge gas inlet1164from gas panel1136to clean window1174. The cleaning agent, whether provided from the RPS1190or gas panel1136, may be energized by lamp1170to increase the energy state of the gases proximate window1174. It is also contemplated that a cleaning agent may be energized by remote photoexcitation system1182and delivered into process chamber1100through inlet port1134.

Controller1146is coupled to the various components of process chamber1100to facilitate control of a silicon nitride deposition process as described below. Controller1146generally includes central processing unit (CPU)1150, memory1148, and support circuits1152. CPU1150may be one of any form of computer processor that can be used in an industrial setting for controlling various chambers and sub processors. Memory1148, or computer readable medium, may be one or more of readily available memory, such as random access memories (RAM), read-only memory (ROM), floppy disk, hard drive, flash memory, or any other form of digital storage, local or remote. Support circuits1152are coupled to CPU1150for supporting the processor in a conventional manner. Support circuits1152include cache, power supplies, clock circuits, input/output circuitry and subsystems, and the like. A process, for example, a deposition process for depositing the silicon-containing material in step1900described below, is generally stored in memory1148, typically as a software routine. The software routine may also be stored and/or executed by a second CPU (not shown) that is remotely located from the hardware being controlled by CPU1150. Although the deposition process of the present invention is described as being implemented as a software routine, some of the method steps that are disclosed therein may be performed in hardware as well as by the software controller. As such, the invention may be implemented in software as executed upon a system computer, in hardware as an application specific integrated circuit or other type of hardware implementation, or a combination of software and hardware.