SILICON NITRIDE AND SILICON OXIDE DEPOSITION METHODS USING FLUORINE INHIBITOR

Methods of depositing material on a surface of a substrate are disclosed. The methods include using a fluorine reactant to reduce a growth rate per cycle of silicon oxide and/or silicon nitride deposited onto a surface of a substrate.

FIELD OF INVENTION

The present disclosure generally relates to methods of depositing material onto a surface of a substrate, to structures formed using the method, and to systems for depositing the material.

BACKGROUND OF THE DISCLOSURE

During the formation of electronic devices, such as semiconductor devices, it may be desirable to fill a gap (e.g., a trench, via, or space between features) on a surface of a substrate with insulating material, such as silicon nitride or silicon oxide. Atomic layer deposition (ALD) can be used to conformally deposit silicon nitride or silicon oxide over gaps and thereby fill the gaps.

In some cases, a plasma-enhanced process, such as plasma-enhanced ALD (PEALD), can be used to deposit silicon nitride or silicon oxide. Plasma-enhanced processes can be operated at relatively low temperatures and/or exhibit relatively high deposition rates, compared to methods that do not employ a plasma.

Unfortunately, silicon nitride and silicon oxide deposited using PEALD on high aspect-ratio features (e.g., gaps having an aspect ratio of three or more) tend to form voids in the deposited material, because less material is deposited at the bottom of a feature (e.g., on a bottom surface or on a side surface near the bottom of the gap—compared to a side surface of the gap at or near the top of the gap). The poor conformality and/or undesired deposition profile of the deposited material can be attributed to a loss of activated species, such as radicals, that can occur by surface recombination of the radicals at, for example, the sidewalls of the gaps.

Efforts to improve low conformality and/or gap-fill ability of PEALD deposited material have focused on tuning process parameters, such as RF power, plasma exposure time, pressure, and the like, so as to provide adequate activated species, such as radicals, near the bottom of a feature, so as to increase an amount of material deposited at the bottom of the feature. However, because recombination of radicals is an intrinsic phenomenon, such efforts have been limited. Moreover, recent device manufacturing specifications often demand low plasma near the bottom of a feature. For such applications, conventional methods that include increasing activated species and/or activated species energy at the bottom of a feature cannot be used.

To overcome such problems, several techniques have been proposed. For example, U.S. Pat. No. 9,887,082 to Pore et al. discloses a method for filling a gap. The method includes providing a precursor into a reaction chamber to form adsorbed species on a surface of a substrate, exposing the adsorbed species to a nitrogen plasma to form species at the top of the feature that include nitrogen, and providing a reactant plasma to the reaction chamber, wherein nitrogen acts as an inhibitor to the reactant, resulting in less material being deposited at the top of the gap, compared to traditional PEALD techniques. Such techniques can result in silicon nitride with fewer voids or seams than traditional techniques, but voids and seams within the silicon nitride can still form, particularly in higher aspect ratio gaps. Further, a wet etch rate of silicon nitride deposited using such techniques can be undesirably high for some applications.

Accordingly, improved methods for depositing material suitable for filling gaps on a surface of a substrate and structures formed using such methods are desired. Any discussion of problems and solutions involved in the related art has been included in this disclosure solely for the purposes of providing a context for the present invention and should not be taken as an admission that any or all of the discussion were known at the time the invention was made.

SUMMARY OF THE DISCLOSURE

Various embodiments of the present disclosure relate to methods of depositing material onto a surface of a substrate—e.g., depositing material over features on the substrate surface—that are suitable for filling gaps on the surface of the substrate. While the ways in which various embodiments of the present disclosure address drawbacks of prior methods and systems are discussed in more detail below, in general, various embodiments of the disclosure provide improved methods suitable for filling the gaps on the surface while mitigating void or seam formation that might otherwise occur using traditional techniques.

In accordance with embodiments of the disclosure, a method of depositing one or more of silicon nitride and silicon oxide onto a surface of a substrate is provided. The method can include providing a fluorine reactant to the reaction chamber for a fluorine reactant pulse, providing a silicon precursor to the reaction chamber for a silicon precursor pulse, providing one or more of a nitrogen reactant and an oxygen reactant to the reaction chamber for a reactant pulse, and optionally providing a hydrogen reactant to the reaction chamber for a hydrogen reactant pulse. When hydrogen is provided, the hydrogen can be introduced to a reaction chamber separately or can be mixed with another reactant, for example, the nitrogen reactant, and introduced to the reaction chamber at the same time with the nitrogen reactant. In accordance with examples of these embodiments, silicon precursor can include one or more of a silane, a halogensilane, and an organosilane. The nitrogen reactant can include one or more of nitrogen (N2), N2O, and NO and/or the oxygen reactant can include, for example, O2. The fluorine reactant can include one or more of NF3, CF4, C2F6, SF6, NH2F, C3F8, and F2. The hydrogen reactant can include or more of hydrogen (H2), NH3, N2H4, and N2H2. As set forth in more detail below, various combinations of the reactants can be continuously supplied to the reaction chamber during two or more method steps. Additionally or alternatively, in some cases, two or more of the method steps can overlap in time and space. In some cases, an order of two or more steps may be specified. In some cases, it may be specified that two or more steps do not overlap. In this context, overlap can mean that the reactants enter or are within the same reaction chamber at the same time (e.g., without an intervening purge). In accordance with further examples of the disclosure, one or more of the reactants may be exposed to a plasma to form activated species. The plasma can be a direct or remote plasma. Methods described herein can be used to form silicon oxide and/or silicon nitride suitable for filling a gap on a surface, suitable for forming a hard mask, or the like.

In accordance with yet further exemplary embodiments of the disclosure, a deposition apparatus configured to perform a method as described herein is provided.

In accordance with yet further exemplary embodiments of the disclosure, a structure comprises silicon oxide and/or silicon nitride deposited according to a method described herein.

These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures; the invention not being limited to any particular embodiment(s) disclosed.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present disclosure generally relates to methods of depositing material onto a surface of a substrate, to deposition apparatus for performing the methods, and to structures formed using the methods. The methods and systems as described herein can be used to process substrates to form, for example, electronic devices. By way of examples, the systems and methods described herein can be used to deposit silicon nitride and/or silicon oxide onto a surface of a substrate, which can include high-aspect ratio features to, for example, fill gaps within or between the high-aspect ratio features.

In this disclosure, “gas” may include material that is a gas at normal temperature and pressure, a vaporized solid and/or a vaporized liquid, and may be constituted by a single gas or a mixture of gases, depending on the context. A gas other than the process gas, i.e., a gas introduced without passing through a gas distribution assembly, such as a showerhead, other gas distribution device, or the like, may be used for, e.g., sealing the reaction space, which includes a seal gas such as a rare gas. In some embodiments, the term “precursor” refers generally to a compound that participates in the chemical reaction that produces another compound, and particularly to a compound that constitutes a film matrix or a main skeleton of a film, whereas the term “reactant” refers to a compound, other than precursors, that activates a precursor, modifies a precursor, or catalyzes a reaction of a precursor, wherein the reactant may provide an element (such as O, N, C) to a film matrix and become a part of the film matrix, when RF power is applied. The term “inert gas” refers to a gas that does not take part in a chemical reaction and/or a gas that excites a precursor when RF power is applied, but, unlike a reactant, may not become a part of a film matrix to an appreciable extent.

As used herein, the term “substrate” may refer to any underlying material or materials that may be used to form, or upon which, a device, a circuit, or a film may be formed. A substrate can include a bulk material, such as silicon (e.g., single-crystal silicon), other Group IV materials, such as germanium, or compound semiconductor materials, such as Group III-V or Group II-VI semiconductors, and can include one or more layers overlying or underlying the bulk material. Further, the substrate can include various topologies, such as recesses, lines, and the like formed within or on at least a portion of a layer of the substrate.

In some embodiments, “film” refers to a layer continuously extending in a direction perpendicular to a thickness direction substantially without pinholes to cover an entire target or concerned surface, or simply a layer covering a target or concerned surface. In some embodiments, “layer” refers to a structure having a certain thickness formed on a surface or a synonym of film or a non-film structure. A film or layer may be constituted by a discrete single film or layer having certain characteristics or multiple films or layers, and a boundary between adjacent films or layers may or may not be clear and may or may not be established based on physical, chemical, and/or any other characteristics, formation processes or sequence, and/or functions or purposes of the adjacent films or layers.

The term “cyclic deposition process” or “cyclical deposition process” can refer to the sequential introduction of precursors (and/or reactants) into a reaction chamber to deposit a layer over a substrate and includes processing techniques such as atomic layer deposition (ALD), cyclical chemical vapor deposition (cyclical CVD), and hybrid cyclical deposition processes that include an ALD component and a cyclical CVD component.

As used herein, the term “atomic layer deposition” (ALD) may refer to a vapor deposition process in which deposition cycles, preferably a plurality of consecutive deposition cycles, are conducted in a process chamber. Typically, during each cycle, a precursor is introduced and may be chemisorbed to a deposition surface (e.g., a substrate surface or a previously deposited underlying surface such as material from a previous ALD cycle), forming a monolayer or sub-monolayer that does not readily react with additional precursor (i.e., a self-limiting reaction). Thereafter, a reactant (e.g., another precursor or reaction gas) may subsequently be introduced into the process chamber for use in converting the chemisorbed precursor to the desired material on the deposition surface. Typically, this reactant is capable of further reaction with the precursor. Further, purging steps may also be utilized during each cycle to remove excess precursor from the process chamber and/or remove excess reactant and/or reaction byproducts from the process chamber after conversion of the chemisorbed precursor. Further, the term “atomic layer deposition,” as used herein, is also meant to include processes designated by related terms, such as chemical vapor atomic layer deposition, atomic layer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE, or organometallic MBE, and chemical beam epitaxy when performed with alternating pulses of precursor composition(s), reactive gas, and purge (e.g., inert carrier) gas. PEALD refers to an ALD process, in which a plasma is applied during one or more of the ALD steps.

As used herein, silicon nitride refers to a material that includes silicon and nitrogen. Silicon nitride can be represented by the formula SixNy(e.g., Si3N4). In some cases, the silicon nitride may not include stoichiometric silicon nitride. In some cases, the silicon nitride can include other elements, such as carbon, oxygen, hydrogen, or the like.

As used herein, silicon oxide refers to a material that includes silicon and oxygen. Silicon oxide can be represented by the formula SiOx(e.g., SiO2). In some cases, the silicon oxide may not include stoichiometric silicon oxide. In some cases, the silicon oxide can include other elements, such as carbon, nitrogen, hydrogen, or the like.

As used herein, silicon oxynitride refers to a material that includes silicon, oxygen, and nitrogen. Silicon oxynitride can be represented by the formula SiOxNy. In some cases, the silicon oxynitride can include other elements, such as carbon, hydrogen, or the like. Silicon oxynitride can include silicon oxide and silicon nitride.

Further, in this disclosure, any two numbers of a variable can constitute a workable range of the variable as the workable range can be determined based on routine work, and any ranges indicated may include or exclude the endpoints. Additionally, any values of variables indicated (regardless of whether they are indicated with “about” or not) may refer to precise values or approximate values and include equivalents, and may refer to average, median, representative, majority, etc. in some embodiments. Further, in this disclosure, the terms “including,” “constituted by” and “having” can refer independently to “typically or broadly comprising,” “comprising,” “consisting essentially of,” or “consisting of” in some embodiments. In this disclosure, any defined meanings do not necessarily exclude ordinary and customary meanings in some embodiments.

In this disclosure, “continuously” can refer to one or more of without breaking a vacuum, without interruption as a timeline, without any material intervening step, without changing treatment conditions, immediately thereafter, as a next step, or without an intervening discrete physical or chemical structure between two structures other than the two structures in some embodiments.

Turning now to the figures,FIG. 1illustrates a method100, suitable for depositing one or more of silicon nitride and silicon oxide onto a surface of a substrate within a reaction chamber in accordance with at least one embodiment of the disclosure. Method100includes the steps of providing a substrate within a reaction chamber (step102), providing a fluorine reactant to the reaction chamber for a fluorine reactant pulse (step104), providing a silicon precursor to the reaction chamber for a silicon precursor pulse (step106), and providing one or more of a nitrogen reactant and an oxygen reactant to the reaction chamber for a reactant pulse (step108). As illustrated, method100can also include providing a hydrogen reactant to the reaction chamber for a hydrogen reactant pulse (step110). Method100can include an a cyclical (e.g., ALD) process, such as a PEALD process.

Step102includes providing at least one substrate into a reaction chamber and bringing the substrate to a desired temperature. The reaction chamber may include a PEALD reaction chamber. A temperature within the reaction chamber during step102can be brought to a temperature for subsequent processing—e.g., between about −10° C. and about 1000° C. or about 75° C. to about 600° C. Similarly, a pressure within the reaction chamber may be controlled to provide a reduced atmosphere in the reaction chamber for subsequent processing. For example, the pressure within the reaction chamber can be brought to less than 5000 Pa, or less than 2000 Pa, or less than 1000 Pa, or be between about 0.0001 Pa and about 101325 Pa or about 10 Pa and about 13333 Pa.

During step104, a surface of a substrate is exposed to a fluorine reactant. During this step, the temperature and/or pressure can be as set forth above in connection with step102. In accordance with examples of the disclosure, a plasma is applied during at least a portion of step104of providing a fluorine reactant to the reaction chamber. The plasma can be a remote plasma, such that activated fluorine species are introduced to the reaction chamber, or a direct plasma, where activated fluorine species are formed within the reaction chamber. In accordance with examples of the disclosure, the activated fluorine species can preferentially react with a top surface of a feature, such as a gap, such that the effects of the fluorine that reacts with the substrate surface is greater near a top of the feature, relative to a bottom of the feature. The presence of fluorine on a surface increases an incubation and/or reduces a growth rate per cycle of subsequently deposited silicon nitride and/or silicon oxide.

A power to produce activated fluorine species during step104can be greater than OW and about 10000 W or about 50 W and about 3000 W. A frequency of the power can be between about 430 kHz and about or about 13.56 MHz.

In accordance with examples of the disclosure, a temperature within the reaction chamber can be relatively low—e.g., less than 25° C. or less than 550° C. to prevent or mitigate etching of material during step104.

The fluorine reactant provided during step104can include any suitable fluorine-containing reactant. By way of examples, the fluorine reactant can be or include one or more of NF3, CF4, C2F6, SF6, NH2F, C3F8, and F2. In some cases, the fluorine reactant can be provided to the reaction chamber and/or a remote plasma unit mixed with a carrier gas, such as an inert gas. Suitable inert or carrier gases include, for example, N2, Ar, He, Ne, Xe.

Exemplary fluorine reactant flow rates during step104can be about 1 sccm to about 1000 sccm or about 2 sccm to about 100 sccm. A pulse time for fluorine reactant flow during step104can be 0.01 seconds to about 600 seconds or about 1 second to about 300 seconds.

In accordance with examples of the disclosure, process conditions for step104can be controlled to mitigate etching of underlying material and/or to control areas that are affected by fluorine reactant. For example, process conditions can be selected, such that growth rates of subsequently formed material are lower in top areas (e.g., the top 25% or top 10%) of features, compared to the remainder of the features. Further, when a hydrogen reactant is used, the hydrogen reactant can promote growth in the lower/remainder portions of the features.

During step106, a silicon precursor is provided to the reaction chamber for a silicon precursor pulse. A pressure and temperature within the reaction chamber can be as noted above in connection with step102. In some cases, a substrate, gas distribution system (e.g., showerhead), and/or reaction chamber wall temperature during step106can be higher than the substrate, gas distribution system, and/or reaction chamber wall temperature during step104—e.g., to facilitate deposition during step106and steps108and110. In accordance with examples of the disclosure, a plasma is not provided during step106.

Exemplary silicon precursor flow rates during step106can be about 1 sccm to about 500 sccm or about 3 sccm to about 100 sccm. A pulse time for silicon precursor flow during step106can be 0.1 seconds to about 10 seconds or about 0.2 second to about 3 seconds.

During step108, one or more of a nitrogen reactant and an oxygen reactant are provided to the reaction chamber for a reactant pulse. A temperature and pressure within the reaction chamber during step108can be the same or similar to the temperature and pressure within the reaction chamber during step104or106.

In accordance with examples of the disclosure, a plasma is applied during at least a portion of step108of providing one or more of a nitrogen reactant and an oxygen reactant to the reaction chamber. The plasma can be a remote plasma or a direct plasma. A power to produce a plasma during step108can be greater than OW and about 10000 W or about 50 W and about 3000 W. A frequency of the power can be between about 400 kHz and about 60 MHz or about 13.56 MHz.

The nitrogen reactant can include a nitrogen-containing compound, such as one or more of nitrogen (N2), N2O, and NO. Additionally or alternatively, the oxygen reactant can include an oxygen-containing compound, such as O2.

Exemplary nitrogen reactant flow rates during step108can be about 100 sccm to about 50000 sccm or about 5000 sccm to about 30000 sccm. A pulse time for nitrogen reactant flow during step108can be 0.05 seconds to about 20 seconds or about 0.1 second to about 10 seconds. Exemplary oxygen reactant flow rates during step108can be about 100 sccm to about 50000 sccm or about 5000 sccm to about 30000 sccm. A pulse time for oxygen reactant flow during step108can be 0.05 seconds to about 20 seconds or about 0.05 second to about 10 seconds.

During optional step110, a hydrogen reactant is provided to the reaction chamber for a hydrogen reactant pulse. A temperature and pressure within the reaction chamber during step110can be the same or similar to the temperature and pressure within the reaction chamber during any of steps104-108, and particularly any of steps106,108.

In accordance with examples of the disclosure, a plasma is applied during at least a portion of step110. The plasma can be a remote plasma or a direct plasma. A power to produce a plasma during step110can be greater than OW and about 10000 W or about 50 W and about 3000 W. A frequency of the power can be between about 400 kHz and about 60 MHz or about 13.56 MHz.

The hydrogen reactant can include, for example, one or more of hydrogen (H2), NH3, N2H4, and N2H2. Exemplary hydrogen reactant flow rates during step108can be about 1 sccm to about 5000 sccm or about 10 sccm to about 500 sccm. A pulse time for hydrogen reactant flow during step108can be 0.1 seconds to about 15 seconds or about 0.5 second to about 5 seconds.

As noted above, use of activated hydrogen and fluorine species can promote deposition in a lower portion of a feature, compared to a top portion of the feature. This may be particularly the case for halogensilanes and/or aminosilane silicon precursors.

Steps106-110can be considered a deposition cycle, which can be repeated (loop112) one or more times. Method100can further include a loop114of repeating steps104-110.

For example, loop114can be repeated a number of times until a gap on a surface of a substrate is filled with the one or more of silicon nitride and silicon oxide and/or a desired film thickness is reached. Further, although not separately illustrated, any of steps104-110can be repeated prior to proceeding to the next step.

Two or more of steps106-110can be performed at the same time or may overlap—at least partially—in time. For example, steps106and110may overlap or be performed at the same time. Additionally or alternatively, steps108and110can overlap. Further, as illustrated in more detail below, one or more steps—e.g., the steps of providing one or more of a nitrogen reactant and an oxygen reactant to the reaction chamber can be performed continuously during the steps of providing a silicon precursor, optionally providing a hydrogen reactant, and/or providing a fluorine reactant.

Further, unless otherwise noted, steps of method100can be performed in any order. In the illustrated example, step104occurs before step106. However, as illustrated below, methods can include a step of introducing a fluorine reactant after one or more deposition cycles. In accordance with some examples, the step of providing a hydrogen reactant (110) and the step of providing a fluorine reactant (104) do not overlap within the reaction chamber.

FIG. 2illustrates a timing sequence200of a method, such as method100, for forming silicon nitride on the surface of the substrate. Timing sequence200includes a fluorine treatment cycle202and a deposition cycle204.

Fluorine treatment cycle202can include providing a purge gas, providing a nitrogen reactant, and providing a fluorine reactant for a first period206(e.g., without a plasma) and a second period208(with a plasma). The conditions for fluorine treatment cycle202can be as described above in connection with steps104and108.

Deposition cycle204can include providing a silicon precursor and the nitrogen reactant for a period210. Then, the reaction chamber can be purged—e.g., using a purge gas and the nitrogen reactant during period212. While the nitrogen reactant continues to flow, a power to produce a plasma can be applied for a period214. Then, the reaction chamber can be purged for a period216. The gas flowrates can be as described above in connection withFIG. 1.

Timing sequence200can include repeating deposition cycle204a number of times. Further, timing sequence200can include repeating fluorine treatment cycle202and deposition cycle204a number of times, as described above in connection withFIG. 1. In the illustrated example, a separate hydrogen reactant is not provided during method200.

FIG. 3illustrates a timing sequence300of a method, such as method100, for forming silicon nitride on the surface of the substrate with a hydrogen reactant. Timing sequence300includes a fluorine treatment cycle302and a deposition cycle304.

Fluorine treatment cycle302can include providing a purge gas, providing a nitrogen reactant, and providing a fluorine reactant for a first period306(e.g., without a plasma) and a second period308(with a plasma), as described above in connection with fluorine treatment step202.

Deposition cycle304can include providing a silicon precursor and the nitrogen reactant for a period310. Then, the reaction chamber can be purged—e.g., using a purge gas, the nitrogen reactant, and the hydrogen reactant during period312. While the nitrogen reactant and hydrogen reactant continue to flow, a power to produce a plasma can be applied for a period314to produce nitrogen and hydrogen activated species. Then, the reaction chamber can be purged for a period316.

Timing sequence300can include repeating deposition cycle304a number of times. Further, timing sequence300can include repeating fluorine treatment cycle302and deposition cycle304a number of times, as described above in connection withFIG. 1. Various gas flowrates during periods306-316can be as described above in connection withFIG. 1.

FIG. 4illustrates a timing sequence400of a method, such as method100, for forming silicon oxide on the surface of the substrate without an additional hydrogen reactant. Timing sequence400is similar to timing sequence200(except timing sequence400includes an oxygen reactant, rather than a nitrogen reactant). Timing sequence400includes a fluorine treatment cycle402and a deposition cycle404.

Fluorine treatment cycle402can include providing a purge gas, providing a nitrogen reactant, and providing a fluorine reactant for a first period406(e.g., without a plasma) and a second period408(with a plasma), as described above in connection with fluorine treatment step202.

Deposition cycle404can include providing a silicon precursor and the oxygen reactant for a period410. Then, the reaction chamber can be purged—e.g., using a purge gas and the oxygen reactant during period412. While the oxygen reactant continues to flow, a power to produce a plasma can be applied for a period414to produce oxygen activated species. Then, the reaction chamber can be purged for a period416.

Timing sequence400can include repeating deposition cycle404a number of times. Further, timing sequence400can include repeating fluorine treatment cycle402and deposition cycle404a number of times, as described above in connection withFIG. 1.

FIG. 5illustrates a timing sequence500of a method, such as method100, for forming silicon oxide on the surface of the substrate with a hydrogen reactant. Timing sequence500includes a fluorine treatment cycle502and a deposition cycle504.

Fluorine treatment cycle502can include providing a purge gas, providing an oxygen reactant (e.g., with a carrier gas), and providing a fluorine reactant for a first period506(e.g., without a plasma) and a second period508(with a plasma), as described above in connection with fluorine treatment step202.

Deposition cycle504can include providing a silicon precursor and the oxygen reactant for a period510. Then, the reaction chamber can be purged—e.g., using a purge gas, the oxygen reactant and/or carrier gas, and the hydrogen reactant during period512. While the oxygen reactant and hydrogen reactant continue to flow, a power to produce a plasma can be applied for a period514to produce oxygen and hydrogen activated species. Then, the reaction chamber can be purged for a period516.

Timing sequence500can include repeating deposition cycle504a number of times. Further, timing sequence500can include repeating fluorine treatment cycle502and deposition cycle504a number of times, as described above in connection withFIG. 1.

FIG. 6illustrates a method600, suitable for depositing one or more of silicon nitride and silicon oxide onto a surface of a substrate within a reaction chamber in accordance with at least one embodiment of the disclosure. Method600includes the steps of providing a substrate within a reaction chamber (step602), providing a silicon precursor to the reaction chamber for a silicon precursor pulse (step604), providing one or more of a nitrogen reactant and an oxygen reactant to the reaction chamber for a reactant pulse (step606), and providing a fluorine reactant to the reaction chamber for a fluorine reactant pulse (step610). As illustrated, method600can also include providing a hydrogen reactant to the reaction chamber for a hydrogen reactant pulse (step608). Steps604-610can be the same or similar to the respective steps in method100; however, in method600, step610is performed after a deposition cycle including steps604-608, rather than before the deposition cycle.

FIG. 7illustrates a timing sequence700of a method, such as method600, for forming one or more of silicon nitride and silicon oxide onto a surface of a substrate. Timing sequence700includes a deposition cycle702and a fluorine treatment cycle704.

Deposition cycle702can include providing a silicon precursor and a reactant and a hydrogen reactant for a period706. Then, the reaction chamber can be purged—e.g., using a purge gas, the reactant, and the hydrogen reactant during period708. While the reactant and hydrogen reactant continue to flow, a power to produce a plasma can be applied for a period710to produce reactant and hydrogen activated reactant species. Optionally, the reaction chamber can then be purged for a reactant purge period (not illustrated).

Fluorine treatment cycle704can include providing a purge gas and reactant (e.g., exclusive of the hydrogen reactant) and a fluorine reactant for a first period712(e.g., without a plasma) and a second period714(with a plasma), as described above in connection with fluorine treatment step202. The reaction chamber can then be purged for a fluorine reactant purge period716.

Timing sequence700can include repeating deposition cycle702a number of times. Further, timing sequence700can include repeating deposition cycle702and fluorine treatment cycle704a number of times, as described above in connection withFIG. 6.

FIG. 8illustrates another timing sequence800of a method, such as method600, for forming one or more of silicon nitride and silicon oxide onto a surface of a substrate. Timing sequence800includes a deposition cycle802, a hydrogen cycle804, and a fluorine treatment cycle806.

In the illustrated example, deposition cycle802includes providing a silicon precursor and a reactant for a period808. Then, the reaction chamber can be purged—e.g., using a purge gas and the reactant during period810. While the reactant continues to flow, a power to produce a plasma can be applied for a period812to produce reactant activated species. The reaction chamber can then be purged for a reactant purge period814.

Hydrogen cycle804includes providing hydrogen reactant to the reaction chamber and providing power to a plasma unit for a period816. The reactor conditions for step804can be as described above in connection with step608.

Fluorine treatment cycle806can include providing a purge gas and reactant (e.g., exclusive of the hydrogen reactant) and a fluorine reactant for a period818, during at least a portion of which a plasma is applied. The plasma conditions can be as described above in connection withFIGS. 1 and 6. The reaction chamber can then be purged for a fluorine reactant purge period (not separately illustrated).

Timing sequence800can include repeating deposition cycle802a number of times—e.g., prior to proceeding to steps804and806. Further, timing sequence800can include repeating deposition cycle802, hydrogen cycle816, and/or fluorine treatment cycle818a number of times, as illustrated inFIG. 8.

FIG. 9illustrates a structure900including gaps902and904formed on a surface of a substrate906. Structure900includes a silicon nitride or silicon oxide layer908formed according to traditional methods overlying substrate906. As illustrated, silicon nitride or silicon oxide layer908has a thickness t1near a top of gap902that is greater than a thickness of layer908at the bottom of gap902. As gap902fills using the traditional technique, a void can form within gap902.

FIG. 10illustrates a structure1000including gaps1002and1004formed on a surface of a substrate1006. Structure1000includes one or more of silicon nitride and silicon oxide1008formed according to a method as described herein—e.g., method100or method600. As illustrated, one or more of silicon nitride and silicon oxide1008has a thickness t1near a top of gap1002that is less than a thickness of layer1008at the bottom of gap1002. As further illustrated inFIG. 11, as gap1002fills using exemplary methods disclosed herein, no void forms within gap1002. The conformality of deposited silicon nitride and/or silicon oxide can be greater than 100% or even greater than 200%, where conformality (%)=side(btm) thickness/side(top) thickness*100.

Turning now toFIG. 12, a reactor system1200is illustrated in accordance with exemplary embodiments of the disclosure. Reactor system1200can be used to perform one or more steps or sub steps as described herein and/or to form one or more structures or portions thereof as described herein.

Reactor system1200includes a pair of electrically conductive flat-plate electrodes4, 2 in parallel and facing each other in the interior11(reaction zone) of a reaction chamber3. A plasma can be excited within reaction chamber3by applying, for example, HRF power (e.g., 100 kHz, 13.56 MHz, 27 MHz, 2.45 GHz, or any values therebetween) from power source25to one electrode (e.g., electrode4) and electrically grounding the other electrode (e.g., electrode2). A temperature regulator is provided in a lower stage2(the lower electrode), and a temperature of a substrate1placed thereon can be kept at a desired temperature, such as the substrate temperatures noted above. Electrode4can serve as a gas distribution device, such as a shower plate or showerhead. Precursor gas, oxygen and/or nitrogen reactant gases, hydrogen reactant gas, fluorine reactant gas, and dilution/carrier gas, if any, or the like can be introduced into reaction chamber3using one or more of a gas line23, a gas line24, a gas line25, and a gas line27, from sources21,22,20, and26, respectively, and through the shower plate4. Although illustrated with four gas lines23,24,25, and26, reactor system1200can include any suitable number of gas lines. By way of examples, source21can correspond to a silicon precursor source, source22can correspond to one or more of an oxygen reactant source and a nitrogen reactant source, source20can correspond to a hydrogen reactant source, and source26can correspond to a fluorine reactant source.

In reaction chamber3, a circular duct13with an exhaust line7is provided, through which gas in the interior11of the reaction chamber3can be exhausted. Additionally, a transfer chamber5, disposed below the reaction chamber3, is provided with a seal gas line24to introduce seal gas into the interior11of the reaction chamber3via the interior16(transfer zone) of the transfer chamber5, wherein a separation plate14for separating the reaction zone and the transfer zone is provided (a gate valve through which a substrate is transferred into or from the transfer chamber5is omitted from this figure). The transfer chamber is also provided with an exhaust line6. In some embodiments, the deposition and/or fluorine treatment steps are performed in the same reaction space, so that two or more (e.g., all) of the steps can continuously be conducted without exposing the substrate to air or other oxygen-containing atmosphere.

In some embodiments, continuous flow of a carrier gas to reaction chamber3can be accomplished using a flow-pass system (FPS), wherein a carrier gas line is provided with a detour line having a precursor reservoir (bottle), and the main line and the detour line are switched, wherein when only a carrier gas is intended to be fed to a reaction chamber, the detour line is closed, whereas when both the carrier gas and a precursor gas are intended to be fed to the reaction chamber, the main line is closed and the carrier gas flows through the detour line and flows out from the bottle together with the precursor gas. In this way, the carrier gas can continuously flow into the reaction chamber, and can carry the precursor gas in pulses by switching between the main line and the detour line, without substantially fluctuating pressure of the reaction chamber.

Reactor system1200can include one or more controller(s)26programmed or otherwise configured to cause one or more method steps as described herein to be conducted. Controller(s)26are coupled with the various power sources, heating systems, pumps, robotics and gas flow controllers, or valves of the reactor, as will be appreciated by the skilled artisan. By way of example, controller26can be configured to control gas flow of a silicon precursor, a nitrogen and/or oxygen reactant, optionally a hydrogen reactant, and a fluorine reactant into at least one of one or more reaction chambers to form one or more of a silicon nitride layer and a silicon oxide layer on a surface of a substrate.

In some embodiments, a dual chamber reactor (two sections or compartments for processing substrates disposed close to each other) can be used, wherein a reactant gas and a noble gas can be supplied through a shared line, whereas a precursor gas is supplied through unshared lines.

The example embodiments of the disclosure described above do not limit the scope of the invention, since these embodiments are merely examples of the embodiments of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the disclosure, in addition to those shown and described herein, such as alternative useful combinations of the elements (e.g., steps) described, may become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to fall within the scope of the appended claims.