In-situ deposition process

Embodiments of the present disclosure provide methods and apparatus for forming a desired material layer on a substrate between, during, prior to or after a patterning process. In one embodiment, a method for forming a material layer on a substrate includes pulsing a first gas precursor onto a surface of a substrate, attaching a first element from the first gas precursor onto the surface of the substrate, maintaining a substrate temperature less than about 110 degrees Celsius, pulsing a second gas precursor onto the surface of the substrate, and attaching a second element from the second gas precursor to the first element on the surface of the substrate.

BACKGROUND

Field

Examples of the present disclosure generally relate to a deposition process. Particularly, embodiments of the present disclosure provide methods for forming a material layer on a substrate using an in-situ deposition process in an etching chamber.

Description of the Related Art

In the manufacture of integrated circuits (IC), or chips, patterns representing different layers of the chip are created by a chip designer. A series of reusable masks, or photomasks, are created from these patterns in order to transfer the design of each chip layer onto a semiconductor substrate during the manufacturing process. Mask pattern generation systems use precision lasers or electron beams to image the design of each layer of the chip onto a respective mask. The masks are then used much like photographic negatives to transfer the circuit patterns for each layer onto a semiconductor substrate. These layers are built up using a sequence of processes and translate into the tiny transistors and electrical circuits that comprise each completed chip. Thus, any defects in the mask may be transferred to the chip, potentially adversely affecting performance. Defects that are severe enough may render the mask completely useless. Typically, a set of 15 to 100 masks is used to construct a chip and can be used repeatedly.

With the shrinking of critical dimensions (CD), present optical lithography is approaching a technological limit at the 45 nanometer (nm) technology node. Next generation lithography (NGL) is expected to replace the conventional optical lithography method, for example, in the 20 nm technology node and beyond. The images of the patterned mask are projected through the high-precision optical system onto the substrate surface, which is coated with a layer of photoresist. The patterns are then formed on the substrate surface after complex chemical reactions and follow-on manufacturing steps, such as development, post-exposure bake and wet or dry etching.

Multiple patterning technique is a technology developed for photolithography to enhance the feature density and accuracy. This technique is commonly used for patterns in the same layer which look different or have incompatible densities or pitches. Furthermore, between each patterning process, additional layers or structures may be formed, added or replenished in order to enable the next patterning process. Conventionally, the substrate is moved from the patterning or etching chamber to a deposition chamber. Thus, additional materials may be formed or replenished on the substrate in the deposition process in preparation of the subsequent patterning or etching process. However, transfer of the substrate between different processing chambers often increases likelihood of contamination on the substrate. Furthermore, transfer of the substrate between different processing chambers is often time-consuming, thus impacting the process throughput and cycle time.

Therefore, there is a need for an apparatus for performing a patterning process with a desired material or deposition replenishing mechanism during the patterning process.

SUMMARY

Embodiments of the present disclosure provide methods and apparatus for forming a desired material layer on a substrate between, during, prior to or after a patterning process. In one embodiment, a method for forming a material layer on a substrate includes pulsing a first gas precursor onto a surface of a substrate, attaching a first element from the first gas precursor onto the surface of the substrate, maintaining a substrate temperature less than about 110 degrees Celsius, pulsing a second gas precursor onto the surface of the substrate, and attaching a second element from the second gas precursor to the first element on the surface of the substrate.

In another embodiment, a method for forming a material layer on a substrate includes pulsing a first gas precursor comprising a first element to a substrate disposed in an etching processing chamber, pulsing a second gas precursor comprising a second element to the substrate disposed in the etching processing chamber, and forming a material layer on a surface of the substrate in the etching processing chamber, wherein the material layer comprising the first and the second elements.

In yet another embodiment, a method for forming a material layer on a substrate includes sequentially pulsing a first and a second gas precursor to a surface of a substrate disposed in an etching process chamber, and forming a first layer on a first location of a substrate and a second layer on a second location of a substrate.

It is to be noted, however, that the appended drawings illustrate only exemplary embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

DETAILED DESCRIPTION

Methods for patterning features and manufacturing nanostructures with desired small dimensions in a film stack are provided. The methods utilize a directional etching process to pattern material layers in the film stack layer at a desired angle, to laterally or directionally etch the material layers as needed. By doing so, an etching rate may be altered or modified while etching the features in the material layer in the film stack with different feature densities to improve etching selectivity and enhance feature transfer dimension and profile control.

The term “substrate” as used herein refers to a layer of material that serves as a basis for subsequent processing operations and includes a surface to be cleaned. For example, the substrate can include one or more material containing silicon containing materials, group IV or group III-V containing compounds, such as Si, polysilicon, amorphous silicon, Ge, SiGe, GaAs, InP, InAs, GaAs, GaP, InGaAs, InGaAsP, GaSb, InSb and the like, or combinations thereof. Furthermore, the substrate can also include dielectric materials such as silicon dioxide, organosilicates, and carbon doped silicon oxides. The substrate may also include one or more conductive metals, such as nickel, titanium, platinum, molybdenum, rhenium, osmium, chromium, iron, aluminum, copper, tungsten, or combinations thereof. Further, the substrate can include any other materials such as metal nitrides, metal oxides and metal alloys, depending on the application. In one or more embodiments, the substrate can form a contact structure, a metal silicide layer, or a gate structure including a gate dielectric layer and a gate electrode layer to facilitate connecting with an interconnect feature, such as a plug, via, contact, line, and wire, subsequently formed thereon, or suitable structures utilized in semiconductor devices.

Moreover, the substrate is not limited to any particular size or shape. The substrate can be a round wafer having a 200 mm diameter, a 300 mm diameter, a 450 mm diameter or other diameters. The substrate can also be any polygonal, square, rectangular, curved or otherwise non-circular workpiece, such as a polygonal glass, plastic substrate used in the fabrication of flat panel displays.

FIG.1is a simplified cutaway view for an exemplary processing chamber100suitable for patterning a material layer disposed on a substrate302in the processing chamber100. The exemplary processing chamber100is suitable for performing a patterning process. One example of the processing chamber100that may be adapted to benefit from the disclosure is an CENTRIS® Sym3™ etching processing chamber, available from Applied Materials, Inc., located in Santa Clara, Calif. It is contemplated that other process chambers, including those from other manufactures, may be adapted to practice embodiments of the disclosure.

The plasma processing chamber100includes a chamber body105having a chamber volume101defined therein. The chamber body105has sidewalls112and a bottom118which are coupled to ground126. The sidewalls112have a liner115to protect the sidewalls112and extend the time between maintenance cycles of the plasma processing chamber100. The dimensions of the chamber body105and related components of the plasma processing chamber100are not limited and generally are proportionally larger than the size of the substrate302to be processed therein. Examples of substrate sizes include 200 mm diameter, 250 mm diameter, 300 mm diameter and 450 mm diameter, among others.

The chamber body105supports a chamber lid assembly110to enclose the chamber volume101. The chamber body105may be fabricated from aluminum or other suitable materials. A substrate access port113is formed through the sidewall112of the chamber body105, facilitating the transfer of the substrate302into and out of the plasma processing chamber100. The access port113may be coupled to a transfer chamber and/or other chambers of a substrate processing system (not shown).

A pumping port145is formed through the sidewall112of the chamber body105and connected to the chamber volume101. A pumping device (not shown) is coupled through the pumping port145to the chamber volume101to evacuate and control the pressure therein. The pumping device may include one or more pumps and throttle valves.

A gas panel160is coupled by a gas line167to the chamber body105to supply process gases into the chamber volume101. The gas panel160may include one or more process gas sources161,162,163,164and may additionally include inert gases, non-reactive gases, and reactive gases, if desired. Examples of process gases that may be provided by the gas panel160include, but are not limited to, hydrocarbon containing gas including methane (CH4), sulfur hexafluoride (SF6), silicon chloride (SiCl4), carbon tetrafluoride (CF4), hydrogen bromide (HBr), hydrocarbon containing gas, argon gas (Ar), chlorine (Cl2), nitrogen (N2), helium (He) and oxygen gas (O2). Additionally, process gasses may include nitrogen, chlorine, fluorine, oxygen and hydrogen containing gases such as BCl3, C2F4, C4F8, O4F6, CHF3, CH2F2, CH3F, NF3, NH3, CO2, SO2, CO, N2, NO2, N2O and H2among others.

Valves166control the flow of the process gases from the sources161,162,163,164from the gas panel160and are managed by a controller165. The flow of the gases supplied to the chamber body105from the gas panel160may include combinations of the gases.

The lid assembly110may include a nozzle114. The nozzle114has one or more ports for introducing the process gases from the sources161,162,164,163of the gas panel160into the chamber volume101. After the process gases are introduced into the plasma processing chamber100, the gases are energized to form plasma. An antenna148, such as one or more inductor coils, may be provided adjacent to the plasma processing chamber100. An antenna power supply142may power the antenna148through a match circuit141to inductively couple energy, such as RF energy, to the process gas to maintain a plasma formed from the process gas in the chamber volume101of the plasma processing chamber100. Alternatively, or in addition to the antenna power supply142, process electrodes below the substrate302and/or above the substrate302may be used to capacitively couple RF power to the process gases to maintain the plasma within the chamber volume101. The operation of the power supply142may be controlled by a controller, such as controller165, that also controls the operation of other components in the plasma processing chamber100.

A substrate support pedestal135is disposed in the chamber volume101to support the substrate302during processing. The substrate support pedestal135may include an electrostatic chuck122for holding the substrate302during processing. The electrostatic chuck (ESC)122uses the electrostatic attraction to hold the substrate302to the substrate support pedestal135. The ESC122is powered by an RF power supply125integrated with a match circuit124. The ESC122comprises an electrode121embedded within a dielectric body. The electrode121is coupled to the RF power supply125and provides a bias which attracts plasma ions, formed by the process gases in the chamber volume101, to the ESC122and substrate302positioned thereon. The RF power supply125may cycle on and off, or pulse, during processing of the substrate302. The ESC122has an isolator128for the purpose of making the sidewall of the ESC122less attractive to the plasma to prolong the maintenance life cycle of the ESC122. Additionally, the substrate support pedestal135may have a cathode liner136to protect the sidewalls of the substrate support pedestal135from the plasma gases and to extend the time between maintenance of the plasma processing chamber100.

Furthermore, the electrode121is coupled to a power source150. The power source150provides a chucking voltage of about 200 volts to about 2000 volts to the electrode121. The power source150may also include a system controller for controlling the operation of the electrode121by directing a DC current to the electrode121for chucking and de-chucking the substrate302.

The ESC122may include heaters disposed therein and connected to a power source (not shown), for heating the substrate, while a cooling base129supporting the ESC122may include conduits for circulating a heat transfer fluid to maintain a temperature of the ESC122and substrate302disposed thereon. The ESC122is configured to perform in the temperature range required by the thermal budget of the device being fabricated on the substrate302. For example, the ESC122may be configured to maintain the substrate302at a temperature of about minus about 25 degrees Celsius to about 500 degrees Celsius for certain embodiments.

The cooling base129is provided to assist in controlling the temperature of the substrate302. To mitigate process drift and time, the temperature of the substrate302may be maintained substantially constant by the cooling base129throughout the time the substrate302is in the cleaning chamber. In one embodiment, the temperature of the substrate302is maintained throughout subsequent cleaning processes at about 30 to 120 degrees Celsius.

A cover ring130is disposed on the ESC122and along the periphery of the substrate support pedestal135. The cover ring130is configured to confine etching gases to a desired portion of the exposed top surface of the substrate302, while shielding the top surface of the substrate support pedestal135from the plasma environment inside the plasma processing chamber100. Lift pins (not shown) are selectively moved through the substrate support pedestal135to lift the substrate302above the substrate support pedestal135to facilitate access to the substrate302by a transfer robot (not shown) or other suitable transfer mechanism.

The controller165may be utilized to control the process sequence, regulating the gas flows from the gas panel160into the plasma processing chamber100and other process parameters. Software routines, when executed by the CPU, transform the CPU into a specific purpose computer (controller) that controls the plasma processing chamber100such that the processes are performed in accordance with the present disclosure. The software routines may also be stored and/or executed by a second controller (not shown) that is collocated with the plasma processing chamber100.

FIG.2is a flow diagram of one example of a method200for in-situ deposition process for depositing a material layer on a substrate prior to, between or after a patterning process in an etching or patterning processing chamber. The material layer may be later utilized to serve as a mask layer, a spacer layer or a passivation layer to further alter dimensions or profiles of the features on the substrate for further feature transfer to the underlying layers disposed under the material layer.FIGS.3A-3E and4A-4Bare cross-sectional views of a portion of a substrate302with a structure304formed thereon corresponding to various stages of the method200. The method200may be utilized to deposit material layers onto structures304formed on the substrate302with different material requirements so as to form multiple mask layers, which may be utilized as an etching mask to form features into underlying layers formed on the substrate302. Suitable materials for the underlying layers (not shown) may include an interlayer dielectric layer, contact dielectric layer, a gate electrode layer, a gate dielectric layer, a STI insulating layer, inter-metal layer (IML), or any suitable layers. Alternatively, the method200may be beneficially utilized to form materials on suitable types of structures as needed.

The method200begins at operation202by providing the substrate302having the structure304formed thereon. The substrate302is placed in a processing chamber, such as the processing chamber100depicted inFIG.1to perform a deposition process. In one example, the processing chamber100is an etching chamber or a patterning chamber that allows the substrate302to be disposed therein to perform a deposition process. The structure304includes patterned features formed in a desired distance away from each other. In one embodiment, the structure304may be fabricated from a dielectric layer or a photoresist layer utilized to form a layer in a semiconductor device. Suitable examples of the dielectric layer include carbon-containing silicon oxides (SiOC), polymer materials, such as polyamides, SOG, USG, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbide, or the like.

In the example wherein the structure304includes a photoresist layer, the photoresist layer may be utilized for extreme ultraviolet (EUV) applications as needed. The patterned photoresist layer may be an organic resist layer. In the example wherein the structure304includes a dielectric layer, the dielectric layer may be a silicon oxide, silicon nitride, silicon oxynitride (SiON), silicon oxycarbide (SiOC), or amorphous carbon materials as needed.

At operation204, a first gas precursor354is supplied into the processing chamber100into the surface of the substrate302, as shown inFIG.3B. In one example, the first gas precursor354includes a first element, which may have high absorption to the substrate302as well as to the structure304. For example, when the substrate302and/or the structure304includes atoms or elements that are the same as the atoms or elements in the first gas precursor354, the atoms or elements from the first gas precursor354may be successfully adhered, absorbed or attached to the atoms or elements from the substrate302and/or from the structure304to enhance the attachment and bonding therebetween. For example, when the substrate302and/or the structure304include silicon elements, the first element from the first gas precursor354as selected here also includes a silicon element so that the silicon element from the first gas precursor354may be successfully adhered, absorbed or attached to the silicon elements from the substrate302and/or the structure304. Suitable examples of the first gas precursor354is a silicon containing gas, such as SiCl4, SiH4, Si2Cl6, SiF4, disilane (Si2H6), trisilane (Si3H6), tetrasilane (Si4H10), methyl silane (SiCH6), dimethylsilane (SiC2H6), and the like, and the silicon elements is served as the first element from the first gas precursor354to be absorbed onto the surfaces of the substrate302and/or the structure304.

The first gas precursor354is pulsed into the processing chamber100to perform an ALD-like process. For example, each pulse of an ALD process enables the growth and deposition of a monolayer of a material layer. The atomic layer deposition (ALD) process is a chemical vapor deposition (CVD) process with self-terminating/limiting growth. The ALD process yields a thickness of only a few angstroms or in a monolayer level. The ALD process is controlled by distribution of a chemical reaction into two separate half reactions which are repeated in cycles, which are included in operation204and208in method200described herein. The thickness of the material layer formed by the ALD process depends on the number of reaction cycles. The first gas precursor pulse lasts for a predetermined time interval. The term pulse as used herein refers to a dose of material injected into the process chamber.

The first reaction form the first gas precursor354at operation204provides a first atomic layer of molecular layer (e.g., sourced from the first element from the first gas precursor) being absorbed on the substrate and a second reaction of a second element from a second gas precursor, which will be described later at operation208, provides a second atomic layer of molecular layer being absorbed on the first atomic and/or mono layer. In the example depicted inFIG.3B, the first gas precursor354includes two elements, such as silicon elements306and chlorine elements308, when the first gas precursor354is SiCl4. The silicon elements306is absorbed and adhered onto the top surface310and sidewalls312of the structure304as well as an upper surface314of the substrate302, which also have silicon elements. The chlorine elements308, which does not share the same elements from the substrate302and/or the structure304, is then dangling adjacent to the structure304, with loose bonds or no bonds, to the structure304and/or the substrate302.

Several process parameters are also regulated during pulsing of the first gas precursor. In one embodiment, the process pressure is controlled at between about 1 mTorr and about 100 mTorr. The processing temperature is maintained at less than about 110 degrees Celsius, such as between about −10 degrees Celsius and about 120 degrees Celsius, such as between about 20 degrees Celsius and about 100 degrees Celsius. The RF source power may be controlled at between about 100 watts and about 2500 watts, such as between about 500 watts and about 1000 watts. The RF bias power may be controlled at between about 10 watts and about 500 watts, such as between about 50 watts and about 100 watts. The first gas precursor may be supplied at between about 5 sccm and about 150 sccm. Each pulse of the first precursor gas may deposit the first monolayer of the material layer360having a thickness between about 3 Å and about 5 Å.

At operation206, a purge gas is then supplied to the processing chamber100to purge out the atoms and/or elements (e.g., the chlorine elements308) not attached to the substrate302and/or the structure304, as shown inFIG.3C. Suitable examples of the purge gas include an insert gas, such as Ar or He, a nitrogen containing gas, or other suitable gases.

Several process parameters are also regulated during pulsing of the purge gas mixture. In one embodiment, the process pressure is controlled at between about 1 mTorr and about 100 mTorr. The processing temperature is maintained at less than about 110 degrees Celsius, such as between about −10 degrees Celsius and about 110 degrees Celsius, such as between about 20 degrees Celsius and about 100 degrees Celsius. The RF source power may be controlled at between about 100 watts and about 1200 watts, such as between about 500 watts and about 1000 watts. The RF bias power may be controlled at between about 10 watts and about 200 watts, such as between about 50 watts and about 100 watts. The purge gas may be supplied at between about 5 sccm and about 150 sccm.

At operation208, a second gas precursor362is supplied into the processing chamber100into the surface of the substrate302, as shown inFIG.3D. In one example, the second gas precursor362includes a second element which can react with the first element, such as the silicon element306, on the substrate302and/or the structure304provided from the first gas precursor. The second element as pulsed reacts and bonds with the first element, such as the silicon element306on the surfaces310,314and the sidewall312of the substrate302and/or the structure304. In the example disposed inFIG.3D, the second gas precursor362includes an oxygen or a nitrogen containing gas, providing an oxygen or a nitrogen element320. It is noted that other suitable second gas precursor362that is capable of providing elements or atoms to react with the elements from the first gas precursor may also be utilized as needed. The oxygen or nitrogen element320reacts with the silicon element306. The oxygen or nitrogen element320is then absorbed by the silicon element306on the substrate302and/or the structure304, forming a material layer360on the surfaces314,310and the sidewall312of the substrate302and/or the structure304. In the example wherein the second element is an oxygen element320, the material layer360as formed on the substrate302is a silicon oxide layer. In another example wherein the second element is a nitrogen element320, the material layer360as formed on the substrate302is a silicon nitride layer.

Suitable examples of the oxygen containing gas include O2, CO2, H2O and the like. Suitable examples of the nitrogen containing gas include N2, NO2, N2O, NH3, and the like. In one example, the oxygen containing gas is O2and the nitrogen containing gas is NH3.

Based on different process requirements, process parameters may be controlled differently at operation208. In the example wherein the material layer360is desired to be formed conformally across the substrate302and/or the structure304, as shown inFIGS.3D and3E, a suitable range of RF bias power may be applied to provide directionality of the elements or atoms toward the surfaces314,310and the sidewall312of the substrate302and/or the structure304, as indicated at operation208b. With the assistance from the RF bias power, the elements or atoms from the second gas precursor may stay on the top surface of the structure304as well as accelerated toward the sidewall312of the structure304and the top surface310of the substrate302.

In contrast, in the example wherein the material layer360is desired to be formed selectively on the top surface310of the structure304, as shown inFIGS.4A and4B, the supply of RF bias power may be eliminated so that the second element402is relatively floated and widely distributed close to the top surface310of the structure304, as indicated at operation208a. As the second element402is bonded with first element306by surface absorption (e.g., the ALD-like process), when the second element402from the second gas precursor is pulsed to the substrate surface, the second element402then first meets with the first element306located at the top surface310of the structure304, predominately forming the material layer360on the top surface310of the structure304. Thus, by controlling the supply of the RF bias power during operation208, the material layer360may be formed at different locations of the substrate302and the structure304.

Several process parameters are also regulated during pulsing of the second gas precursor362. In one embodiment, the process pressure is controlled at between about 1 mTorr and about 100 mTorr. The processing temperature is maintained at less than about 110 degrees Celsius, such as between about −10 degrees Celsius and about 110 degrees Celsius, such as between about 20 degrees Celsius and about 100 degrees Celsius. The RF source power may be controlled at between about 100 watts and about 2500 watts, such as about 500 watts and about 1000 watts. The RF bias power may be optionally supplied while supplying the second gas precursor. At operation208ato form the material layer360predominately on the top surface310of the structure304, as shown inFIGS.4A-4B, the RF bias power may be eliminated. In contrast, in operation208bto form the material layer360conformally across the substrate302and the structure304on the substrate302, as shown inFIGS.3D-3E, the RF bias power may be controlled at between about 10 watts and about 500 watts, such as between about 50 watts and about 100 watts. The second gas precursor may be supplied at between about 5 sccm and about 150 sccm. Each pulse of the second precursor gas may deposit the first monolayer of the material layer360having a thickness between about 3 Å and about 15 Å.

At operation210, a purge gas is then supplied to the processing chamber100to purge out the atoms and/or elements not attached to the substrate302and/or the structure304, as shown inFIGS.3E and4B, similar to the purge gas supply at operation206. Suitable examples of the purge gas include an insert gas, such as Ar or He, a nitrogen containing gas, or other suitable gases.

Several process parameters are also regulated during pulsing of the purge gas mixture. In one embodiment, the process pressure is controlled at between about 1 mTorr and about 100 mTorr. The processing temperature is maintained at less than about 110 degrees Celsius, such as between about −10 degrees Celsius and about 120 degrees Celsius, such as between about 20 degrees Celsius and about 100 degrees Celsius. The RF source power may be controlled at between about 100 watts and about 2500 watts, such as between about 500 watts and about 1000 watts. The RF bias power may be controlled at between about 10 watts and about 500 watts, such as between about 50 watts and about 100 watts. The purge gas may be supplied at between about 5 sccm and about 150 sccm.

As such, the ordered structure of the monolayers composed from the first elements and the second elements from the operation204and208is then formed on the structured material layer360at desired locations of the substrate302. The first monolayer from the first gas precursor354at operation204is absorbed onto the desired locations of the substrate302and the structure304by a chemical reaction that allows the atoms from the first monolayer to be securely adhered on the atoms the substrate302and the structure304. The subsequently formed second monolayer from the second gas precursor362at operation208is then selectively formed at different locations of the substrate302and the structure304, based on the control of the RF bias power during operation208, thus enabling a deposition of an ALD process.

Between each pulse of the first gas precursor354or the second gas precursor362at operation204and208, the purge gas at operation206may be pulsed into the processing chamber in between each or multiple pulses of the first and/or second gas precursors354,362to remove the impurities or residual precursor gas mixture which is unreacted/non-absorbed by the substrate surface (e.g., unreacted impurities from the reactant gas mixture or others) so they can be pumped out of the processing chamber.

It is noted that additional cycles starting from the pulsing of the first gas precursor354at operation204, the purge gas supply at operation206and the second gas precursor362at operation208can then be repeatedly performed until a desired thickness of the material layer360is obtained. When a subsequent cycle of pulsing the first gas precursor354starts, the process pressure and other process parameters may be regulated to the predetermined level to assist depositing a subsequent monolayer of the material layer360.

FIG.5is a flow diagram of another example of a method500for in-situ deposition process for depositing a material layer on a substrate prior to or after a patterning process in an etching or patterning processing chamber. The material layer may be later utilized to serve as a mask layer, a spacer layer or a passivation layer to further alter dimensions or profiles of the features on the substrate for further feature transfer to the underlying layers disposed under the material layer.FIGS.6A-6Dare cross-sectional views of a portion of a substrate602with the structure304formed thereon corresponding to various stages of the method500. The substrate602may be similar to the substrate302described above. In a specific example, the substrate602includes a polysilicon material.

The method500begins at operation502by providing the substrate602having the structure304formed thereon. The substrate602is placed on the ESC122in the processing chamber100depicted inFIG.1to perform a deposition process. In this particular example, the ESC122temperature is controlled at less than about 50 degrees Celsius so as to control the substrate602disposed thereon also at the temperature range less than about 50 degrees Celsius. In one example, the temperature range is controlled at between about −20 degrees Celsius and about 50 degrees Celsius, such as between about −10 degrees Celsius and about 40 degrees Celsius, for example about 20 degrees Celsius.

At operation504, the first gas precursor610, similar to or the same as the first gas precursor354at operation204, is supplied to the surface604,310of the substrate602and the structure304. Similar to the operation204, the first precursor610includes the first element606that can successfully bond with and attach to the substrate602as well as the structure304. In contrast to the process at operation204, the RF source and/or bias power supplied at operation504are eliminated. In other words, the first element606and the other element608from the compound of the first gas precursor610are not dissociated by the RF source or bias power. Thus, the compound (e.g., the whole molecule) from the first gas precursor610is precipitated, absorbed and fallen on the surface604,310and sidewall312the substrate602and the structure304, as shown inFIG.6A. The first gas precursor610at operation504is the same or similar to the first gas precursor354supplied at operation204. In one example, the first gas precursor at operation504is SiCl4.

At operation506, similar to the operation206, a purge gas is supplied to purge out the unreacted and/or unabsorbed first gas precursor610, as shown inFIG.6B. The operation506is similar to or the same as the operation206described above.

At operation508, similar to the operation208, particularly similar to the operation208a, the second precursor614is supplied to the surface604,310of the substrate602and the structure304without applying a RF bias power. Thus, the RF source power supplied at operation508dissociates the second gas precursor614as well as the molecule absorbed on the substrate602from the first gas precursor610, as shown inFIG.6C. The other element608is then dissociated from the first element606absorbed on the substrate surface. The second element612supplied from the second gas precursor614is then absorbed on the first element606disposed on the surface310the structure304, forming a material layer650. Similar to the operation208, at least one element (e.g., the second element612) from the second gas precursor614at operation508is selected to have high absorption to the first element606from the first gas precursor610absorbed on the substrate surface. In one example, the second gas precursor614at operation508is NH3or N2, when the material layer650to be formed is described to be a SiN layer, or O2, when the material layer650to be formed is described to be a SiO2layer.

The RF bias power may or may not be applied while supplying the second gas precursor614. In the example depicted inFIG.6C, the RF source power is applied without the RF bias power. Thus, the second elements612dissociated from the second gas precursor614are predominately located on the top surface310of the structure304.

At operation510, after the second element612is successfully attached, absorbed to or bonded with the first element606, similar to the operation210, a purge gas is supplied to purge out the unreacted and/or unabsorbed first and second gas precursor610,614, as shown inFIG.6D. The operation510is similar to or the same as the operation210described above. In this example, the top surface604of the substrate602has the compound (e.g., the whole molecule including the first element606and the other element608) from the first gas precursor610while the top surface310of the structure304has the material layer650(including the first element606and the second element612) formed thereon. In some examples, the sidewalls312of the structure304may include the first element606from the first gas precursor610as needed. Thus, in this example, the layers formed on the top surface604of the substrate602is then different from the layers formed on the top surface310of the structure304and/or formed on the sidewalls312of the structure304.

Between each pulse of the first gas precursor610or the second gas precursor614at operation504and508, the purge gas at operation506may be pulsed into the processing chamber in between each or multiple pulses of the first and/or second gas precursors to remove the impurities or residual precursor gas mixture which is unreacted/non-absorbed by the substrate surface (e.g., unreacted impurities from the reactant gas mixture or others) so they can be pumped out of the processing chamber.

It is noted that additional cycles starting from the pulsing of the first gas precursor610at operation504, the purge gas supply at operation506and the second gas precursor614at operation508can then be repeatedly performed until a desired thickness of the material layer650is obtained. When a subsequent cycle of pulsing the first reactant gas mixture starts, the process pressure and other process parameters may be regulated to the predetermined level to assist depositing a subsequent monolayer of the material layer650.

Thus, deposition methods for forming a material layer on a structure of a substrate are provided. The deposition methods utilize an ALD like deposition process to form the material layer in an etching processing chamber so that an etching process may immediately follow after the deposition process of the material layer. Thus, process cycle time and manufacturing throughput may be improved and well managed.