Gap filling process using pulsed high frequency radio frequency (HFRF) plasma

Abstract

Methods for forming metal carbide liners in features formed in a surface of a substrate are described. Each of the features extends a distance into the substrate from the substrate surface and has a bottom and at least one sidewall. The method includes depositing a metal carbide liner in a feature of a surface of a substrate with a plurality of high frequency radio frequency (HFRF) pulses. Semiconductor devices having metal carbide liners and methods of filling gaps with metal carbide liners are also described.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patent application No. 17 / 157,307 filed on January 25, 2021, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] The present disclosure generally relates to methods for gap filling. In particular, the present disclosure relates to a process for filling a gap using a pulsed high frequency radio frequency (HFRF) plasma. Background Art

[0003] In microelectronic device manufacturing, for many applications, narrow trenches with aspect ratios (AR) greater than 10:1 need to be filled without voids. One application is for shallow trench isolation (STI). For this application, the film needs to be of high quality throughout the trench (e.g., with a wet etch rate ratio of less than 2) and have very low leakage. One approach that has been successful in the past is flowable CVD. In this approach, oligomers are carefully formed in the gas phase, condensed on the surface, and then "flowed" into the trench. The as-deposited film quality is very poor and requires processing steps such as steam annealing and UV curing.

[0004] As feature sizes decrease and aspect ratios increase, post-curing methods for as-deposited flowable films become difficult, resulting in films with varying compositions throughout the filled trench.

[0005] Amorphous silicon has been widely used as a sacrificial layer in semiconductor manufacturing processes because amorphous silicon can provide good etch selectivity relative to other films (e.g., silicon oxide, amorphous carbon, etc.). With the reduction of critical dimension (CD) in semiconductor manufacturing, filling high aspect ratio gaps becomes more and more sensitive for advanced wafer manufacturing. Current metal replacement gate processes involve furnace polysilicon or amorphous silicon dummy gates. Due to the nature of the process, a seam is formed in the middle of the Si dummy gate. This seam may open during post-processing and cause structural failure.

[0006] Conventional plasma enhanced chemical vapor deposition (PECVD) of amorphous silicon (a-Si) forms a "mushroom-shaped" film at the top of narrow trenches. This is because the plasma cannot penetrate into deep trenches. The result is that the narrow trench is pinched off from the top; a void or seam is formed at the bottom of the trench.

[0007] Conventional thermal CVD / furnace processes can grow a-Si via thermal decomposition of silicon precursors (e.g., silane, disilane). However, due to insufficient precursor supply or the presence of decomposition byproducts, the deposition rate at the top of the trench is higher than the deposition rate at the bottom of the trench. Narrow seams or gaps can be observed in the trench.

[0008] In addition, many semiconductor device applications include conformal liners. As device dimensions shrink, conventional plasma enhanced chemical vapor deposition of metal carbides (e.g., tungsten carbide) forms a mushroom-shaped film on top of a narrow trench, where the film is very thin at the sidewalls. Since the plasma cannot penetrate into the deep trench, such a shaped film cannot be used as a conformal liner.

[0009] Therefore, there is a need for methods for forming metal carbide conformal liners in semiconductor devices. Summary of the invention

[0010] One or more embodiments of the present disclosure relate to a method for gap filling. A substrate surface of a substrate is exposed to a deposition process, the deposition process comprising a pulsed high frequency radio frequency (HFRF) plasma having a plurality of HFRF pulses to deposit a liner. The substrate surface has a plurality of features formed in the substrate surface. Each of the plurality of features extends from the substrate surface into the substrate a certain distance and has a bottom and at least one sidewall. The liner includes a metal carbide.

[0011] Additional embodiments of the present disclosure relate to methods of forming a liner using HFRF. A metal carbide liner is formed on the sidewalls of a plurality of features formed in a substrate surface. Each feature extends a distance from the substrate surface into the substrate and has at least one sidewall. Forming the liner includes exposing the substrate to a chemical vapor deposition process with a plurality of liner HFRF pulses.

[0012] Further embodiments of the present disclosure relate to methods of forming a liner in a semiconductor device. A metal carbide liner is formed on sidewalls of a plurality of features formed in a substrate surface. Each feature extends a distance from the substrate surface into the substrate and has at least one sidewall. Forming the metal carbide liner includes exposing the substrate to a chemical vapor deposition process using one or more of a tungsten-containing precursor, a molybdenum-containing precursor, or a nickel-containing precursor and a plurality of liner HFRF pulses to form a metal carbide liner having a tensile stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to be able to understand the above-mentioned features of the present disclosure in detail, the present disclosure briefly summarized above can be described in more detail by reference to embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show typical embodiments and are therefore not to be considered as limiting the scope thereof, as the present disclosure may allow other equally effective embodiments.

[0014] Figure 1 A cross-sectional view showing substrate features according to one or more embodiments of the present disclosure; and

[0015] Figure 2A process flow according to one or more embodiments of the present disclosure is shown.

[0016] FIG. 3A to FIG. 3D A cross-sectional schematic representation of a gap filling process according to one or more embodiments of the present disclosure is shown.

[0017] FIG. 4A to FIG. 4B A cross-sectional schematic representation of a metal carbide liner formation process is shown in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0018] Before describing several exemplary embodiments of the present disclosure, it should be understood that the present disclosure is not limited to the details of construction or process steps set forth in the following description. The present disclosure is capable of other embodiments and can be practiced or carried out in various ways.

[0019] As used herein, "substrate" refers to any substrate or material surface formed on a substrate on which film processing is performed during a manufacturing process. For example, depending on the application, the substrate surface on which processing can be performed includes materials such as silicon, silicon oxide, strained silicon, silicon on insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. Substrates include, but are not limited to, semiconductor wafers. The substrate can be exposed to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, electron beam cure, and / or bake the substrate surface. In addition to the film processing directly on the surface of the substrate itself, in the present disclosure, any of the disclosed film processing steps can also be performed on a bottom layer formed on the substrate as disclosed in more detail below, and the term "substrate surface" is intended to include such a bottom layer as indicated by the context. Thus, for example, in the case where a film / layer or a portion of a film / layer has been deposited onto a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0020] One or more embodiments of the present disclosure provide a low temperature silicon gap fill process. By first depositing and then etching a silicon film around some trench structures, a substantially thicker amorphous silicon (a-Si) film volume is produced at the bottom of the trench compared to the sidewalls or top of the trench. Some embodiments provide a method of cyclic deposition and etching to form a seamless silicon gap fill.

[0021] Embodiments of the present disclosure provide methods for depositing films (e.g., amorphous silicon) in high aspect ratio (AR) structures with small dimensions. Some embodiments advantageously provide methods involving cyclic deposition-etch-treat processes that can be performed in a cluster tool environment. Some embodiments advantageously provide seamlessly doped or alloyed high quality amorphous silicon films to fill high AR trenches with small dimensions.

[0022] Figure 1 A partial cross-sectional view of a substrate 100 having a feature 110 is shown. For illustrative purposes, the figures show a substrate having a single feature; however, one skilled in the art will appreciate that there may be more than one feature. The shape of feature 110 may be any suitable shape, including, but not limited to, a groove and a cylindrical through hole. As used in this regard, the term "feature" means any intentional surface irregularity. Suitable examples of features include, but are not limited to, a groove having a top, two sidewalls, and a bottom, a peak having a top and two sidewalls. The feature may have any suitable aspect ratio (the ratio of the depth of the feature to the width of the feature). In some embodiments, the aspect ratio is greater than or equal to approximately 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, or 40:1.

[0023] Substrate 100 has a substrate surface 120. At least one feature 110 forms an opening in substrate surface 120. Feature 110 extends a depth D from substrate surface 120 to bottom surface 112. Feature 110 has a first sidewall 114 and a second sidewall 116 that define a width W of feature 110. The open area formed by the sidewalls and bottom is also referred to as a gap.

[0024] In a gap filling process, a seam is typically formed in the fill material. The size and width of the seam may affect the overall operability of the gap filling component. The size and width of the seam may also be affected by the process conditions and the deposited material. Therefore, one or more embodiments advantageously provide a method for seamless (or void-free) gap filling. Some embodiments of the method advantageously disclose a cyclic deposition-treatment-etch process for gap filling. In some embodiments, the gap filling is seamless.

[0025] Figure 2 and FIG. 3A to FIG. 3D An exemplary gap filling method 200 according to one or more embodiments of the present disclosure is shown. Figure 2In the illustrated embodiment, method 200 is performed on a substrate 100 having at least one feature 110. In some embodiments, feature 110 has an aspect ratio greater than or equal to 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, or 40:1. In some embodiments, method 200 includes depositing a film 220 and etching a film 240. In some embodiments, film deposition 220 and / or film etching 240 are performed in one or more processing chambers in a cluster tool environment. In some embodiments, film deposition 220 and / or film etching 240 include a plurality of high frequency radio frequency (HFRF) pulses. In one or more embodiments, the plasma includes a pulsed HFRF plasma. In some embodiments, the pulsed HFRF plasma includes a plurality of HFRF pulses. In some embodiments, the pulsed HFRF plasma deposits a non-conformal film.

[0026] Some embodiments advantageously provide methods of using plasma to etch material (e.g., Si) faster on the sidewalls of a feature than at the bottom of the feature. Some embodiments advantageously use different etch rates on different surfaces and at different locations to produce bottom-up growth through a cyclic deposition-etch process.

[0027] exist Figure 3A In the illustrated embodiment, substrate 100 has features 110 formed on substrate 100 and two different surfaces: a first surface 350 and a second surface 360. First surface 350 and second surface 360 ​​can be different materials. For example, one of the surfaces can be a metal and the other can be a dielectric. In some embodiments, first surface 350 and second surface 360 ​​have the same chemical composition but different physical properties (e.g., crystallinity). When describing the following method, reference to substrate 100 means first surface 350 and second surface 360 ​​or a single surface in which features 110 are formed.

[0028] exist Figure 3A In the illustrated embodiment, feature 110 is formed by a first surface 350 and a second surface 360. The illustrated feature 110 is a trench, wherein first surface 350 forms the bottom of the feature and second surface 360 ​​forms the sidewalls and top.

[0029] The method 200 of some embodiments includes an optional substrate pretreatment 210. In some embodiments, the substrate is exposed to one or more process conditions to pretreat or prepare the substrate surface for deposition. For example, in some embodiments, the pretreatment densifies the substrate surface or changes the surface termination. In some embodiments, the optional pretreatment 210 includes one or more of polishing, etching, reducing, oxidizing, hydroxylating, annealing, UV curing, electron beam curing, plasma treatment, and / or baking the substrate surface. In some embodiments, the plasma treatment includes NH3 plasma treatment.

[0030] In some embodiments, a liner is formed in feature 110 in liner formation process 215. Liner formation process 215 is an optional process that may be included in method 200 or may be part of a separate method.

[0031] At the deposition process 220, a film 370 is deposited on the substrate 100. In one or more embodiments, the deposited film 370 includes a plasma enhanced chemical vapor deposition (PECVD) process or a plasma enhanced atomic layer deposition (PEALD) process. In some embodiments, the deposition process 220 includes a PECVD process. In some embodiments, the deposition process 220 includes a PEALD process. In some embodiments, the PECVD includes a gap-filling pulsed high frequency radio frequency (HFRF) plasma. In some embodiments, the gap-filling pulsed HFRF plasma includes a plurality of gap-filling HFRF pulses. The gap-filling pulsed HFRF plasma may also be referred to as a "first" HFRF plasma. The use of ordinal numbers such as "first", "second", etc. is used to identify different processes or components and is not intended to imply a particular order of operation or use.

[0032] As used herein, high frequency RF plasma includes high frequency on / off pulses of power. When on, the power is delivered at a radio frequency. Pulse frequency and radio frequency refer to different aspects of the power used to generate the plasma, which can be controlled independently.

[0033] Film 370 can be any suitable film that can be selectively deposited on first surface 350 relative to second surface 360. In some embodiments, film 370 includes silicon. In some embodiments, film 370 consists essentially of silicon. As used in this manner, the term "consisting essentially of" means that the film is greater than or equal to about 90%, 93%, 95%, 98%, or 99% silicon (or a specified substance) in terms of atoms. In some embodiments, film 370 includes amorphous silicon. In some embodiments, film 370 consists essentially of only amorphous silicon. The term "essentially only amorphous silicon" used in this manner means that film 370 is greater than or equal to about 90%, 93%, 95%, 98%, or 99% amorphous silicon.

[0034] Figure 3A The film 370 is shown formed on the substrate surface (top 374), sidewalls 376, and bottom 372 of the feature 110. The film 370 deposited on the substrate will have a film thickness T on the sidewalls of the feature. s , with a film thickness T at the top of the feature (i.e., on the surface of the substrate) t , and has a film thickness T at the bottom of feature 110 b .

[0035] In some embodiments, film 370 is non-conformally formed on at least one feature. As used herein, the term "non-conformally" or "non-conformally" refers to a layer that adheres to and covers an exposed surface non-uniformly, with a thickness variation greater than 10% relative to an average thickness of the film. For example, an average thickness of The membrane will have a value greater than The thickness variation of the film deposited on the sidewalls of the groove is greater than or equal to 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90%. In some embodiments, the film deposited on the sidewalls of the groove is thinner than the film deposited on the bottom of the groove or the surface in which the groove is formed. In some embodiments, the average thickness of the deposited film on the sidewalls is less than or equal to 90%, 80%, 70%, 60%, 50%, 40%, 30% or 20% of the average thickness on the bottom and / or top of the groove.

[0036] In some embodiments, before stopping deposition, film 370 is deposited to an average thickness in the range of 1 nm to 100 nm, 1 nm to 80 nm, 1 nm to 50 nm, 10 nm to 100 nm, 10 nm to 80 nm, 10 nm to 50 nm, 20 nm to 100 nm, 20 nm to 80 nm, or 20 nm to 50 nm. In some embodiments, film 370 is deposited to an average thickness in the range of 5 nm to 100 nm, 5 nm to 80 nm, 5 nm to 40 nm, 5 nm to 30 nm, or 10 nm to 30 nm.

[0037] The process parameters used to deposit film 370 may affect the film thickness at the sidewalls of the feature, the top of the feature, and / or the bottom of the feature. For example, specific precursors and / or reactive species, plasma conditions, temperature, etc. In some embodiments, the thickness T at the top of the feature t Greater than the thickness T at the sidewall of the feature s In some embodiments, the thickness T at the bottom of the feature b Greater than the thickness T at the sidewall of the feature s In some embodiments, the thickness T at the top of the featuret Greater than the thickness T at the bottom of the feature b In some embodiments, the thickness T at the bottom of the feature b Greater than the thickness T at the top of the feature t .

[0038] During the film deposition 220 process, the substrate is exposed to one or more process gases and / or conditions that form the film 370. In some embodiments, a process gas flows into a process region of a process chamber, and a pulsed HFRF plasma is formed from the process gas to deposit the film 370. The process gas of some embodiments includes a silicon precursor and a carrier gas, and the carrier gas is ignited into a plasma by the HFRF power.

[0039] In one or more embodiments, the gap-filling pulsed HFRF plasma is a conductively coupled plasma (CCP) or an inductively coupled plasma (ICP). In some embodiments, the gap-filling pulsed HFRF plasma is a direct plasma or a remote plasma. In some embodiments, each of the plurality of gap-filling HFRF pulses is independently generated at a gap-filling power in the range of 0W to 500W, 50W to 500W, 50W to 400W, 50W to 300W, 50W to 200W, 50W to 100W, 100W to 500W, 100W to 400W, 100W to 300W, 100W to 200W, 200W to 500W, 200W to 400W, or 200W to 300W. In some embodiments, the minimum gap-filling plasma power is greater than 0W. In some embodiments, all gap-filling pulses have the same power. In some embodiments, the power of each pulse in the gap-filling HFRF plasma varies.

[0040] In one or more embodiments, the plurality of gapfill HFRF plasma pulses have a gapfill duty cycle in the range of 1% to 50%, 1% to 45%, 1% to 40%, 1% to 35%, 1% to 30%, 1% to 25%, 1% to 20%, 1% to 15%, 1% to 10%, 5% to 50%, 5% to 45%, 5% to 40%, 5% to 35%, 5% to 30%, 5% to 25%, 5% to 20%, 5% to 15%, 5% to 10%, 10% to 50%, 10% to 45%, 10% to 40%, 10% to 35%, 10% to 30%, 10% to 25%, 10% to 20%, or 10% to 15%. In some embodiments, each of the plasma pulses during the gapfill deposition process has the same duty cycle. In some embodiments, the duty cycle changes during the gapfill deposition process.

[0041] In one or more embodiments, each of the plurality of gap-filling HFRF plasma pulses independently has a pulse width in the following ranges: 5 milliseconds to 50 microseconds, 4 milliseconds to 50 microseconds, 3 milliseconds to 50 microseconds, 2 milliseconds to 50 microseconds, 1 millisecond to 50 microseconds, 800 microseconds to 50 microseconds, 500 microseconds to 50 microseconds, 200 microseconds to 50 microseconds, 5 milliseconds to 100 microseconds, 4 milliseconds to 100 microseconds, 3 milliseconds to 100 microseconds, 2 milliseconds to 100 microseconds, 1 millisecond to 100 microseconds, 800 microseconds to 100 microseconds, 500 microseconds to 100 microseconds, and 200 microseconds to 100 microseconds. In some embodiments, each of the pulse widths is the same during the deposition process. In some embodiments, the pulse width varies during the deposition process.

[0042] In one or more embodiments, each of the plurality of gap-filling HFRF plasma pulses independently has a gap-filling pulse frequency in the range of 0.1 kHz to 20 kHz, 0.1 kHz to 15 kHz, 0.1 kHz to 10 kHz, 0.1 kHz to 5 kHz, 0.5 kHz to 20 kHz, 0.5 kHz to 15 kHz, 0.5 kHz to 10 kHz, 0.5 kHz to 5 kHz, 1 kHz to 20 kHz, 1 kHz to 15 kHz, 1 kHz to 10 kHz, 1 kHz to 5 kHz, 2 kHz to 20 kHz, 2 kHz to 15 kHz, 2 kHz to 10 kHz, or 2 kHz to 5 kHz. In some embodiments, the pulse frequency remains the same during the deposition process. In some embodiments, the pulse frequency varies during the deposition process.

[0043] In one or more embodiments, the plurality of gap-filling HFRF pulses have a gap-filling radio frequency in the range of 5 MHz to 20 MHz, 5 MHz to 15 MHz, 5 MHz to 10 MHz, 10 MHz to 20 MHz, or 10 MHz to 15 MHz. In one or more embodiments, the plurality of gap-filling HFRF pulses have a first radio frequency of 13.56 MHz. In some embodiments, the radio frequency of the pulses is the same during the deposition process. In some embodiments, the radio frequency of the pulses varies during the deposition process. In one or more embodiments, each of the plurality of gap-filling HFRF pulses independently has a first radio frequency in the range of 5 MHz to 20 MHz, 5 MHz to 15 MHz, 5 MHz to 10 MHz, 10 MHz to 20 MHz, or 10 MHz to 15 MHz. In one or more embodiments, each of the plurality of gap-filling HFRF pulses independently has a first radio frequency of 13.56 MHz.

[0044] In one or more embodiments, each of the plurality of gap-filling HFRF pulses has a gap-filling duty cycle in the range of 1% to 50%, 1% to 45%, 1% to 40%, 1% to 35%, 1% to 30%, 1% to 25%, 1% to 20%, 1% to 15%, 1% to 10%, 5% to 50%, 5% to 45%, 5% to 40%, 5% to 35%, 5% to 30%, 5% to 25%, 5% to 20%, 5% to 15%, 5% to 10%, 10% to 50%, 10% to 45%, 10% to 40%, 10% to 35%, 10% to 30%, 10% to 25%, 10% to 20%, or 10% to 15%. In some embodiments, the duty cycle of the pulses is the same during the deposition process. In some embodiments, the duty cycle of the pulses varies during the deposition process.

[0045] The deposition process 220 may occur at any suitable substrate temperature. In some embodiments, during the deposition process 220, the substrate is maintained at 15°C to 250°C, 15°C to 225°C, 15°C to 200°C, 15°C to 175°C, 15°C to 150°C, 15°C to 125°C, 15°C to 100°C, 25°C to 250°C, 25°C to 225°C, 25°C to 200°C, 25°C to 175°C, 25°C to 150°C, 25°C to 125°C, 2 ... Gap fill temperatures in the range of 5°C to 100°C, 50°C to 250°C, 50°C to 225°C, 50°C to 200°C, 50°C to 175°C, 50°C to 150°C, 50°C to 125°C, 50°C to 100°C, 75°C to 250°C, 75°C to 225°C, 75°C to 200°C, 75°C to 175°C, 75°C to 150°C, 75°C to 125°C or 75°C to 100°C.

[0046] In one or more embodiments, the film deposition process 220 includes flowing one or more of a first carrier gas, a precursor, or a first reactant onto the substrate surface. In some embodiments, the carrier gas includes, but is not limited to, argon (Ar), helium He, H2, or N2. In some embodiments, the carrier gas includes helium (He) or is substantially composed of helium (He). In some embodiments, the carrier gas includes argon (Ar). In one or more embodiments, the precursor includes, but is not limited to, silane, disilane, dichlorosilane (DCS), trisilane, or tetrasilane. In some embodiments, the precursor gas includes silane (SiH4). In some embodiments, the precursor gas includes disilane (Si2H6) or is substantially composed of disilane (Si2H6). In some embodiments, the precursor gas is heated in a hot tank to increase the vapor pressure and is transported to the chamber using a carrier gas. In some embodiments, the first reactant gas includes H2.

[0047] In one or more embodiments, each of the gap fill carrier gas, the precursor gas, or the gap fill reactant gas is preferably provided at a flow rate of 40 sccm to 10000 sccm, 40 sccm to 5000 sccm, 40 sccm to 2000 sccm, 40 sccm to 1000 sccm, 40 sccm to 500 sccm, 40 sccm to 100 sccm, 100 sccm to 10000 sccm, 100 sccm to 5000 sccm, 100 sccm to 2000 sccm, 100 sccm to 1 A dose within the range of 1000 sccm, 100 to 500 sccm, 250 sccm to 10000 sccm, 250 sccm to 5000 sccm, 250 sccm to 2000 sccm, 250 sccm to 1000 sccm, 250 sccm to 500 sccm, 500 sccm to 10000 sccm, 500 sccm to 5000 sccm, 500 sccm to 2000 sccm or 500 sccm to 1000 sccm independently flows onto the substrate surface.

[0048] In some embodiments, Figure 3A As shown, the film 370 deposited during the deposition process 220 is a continuous film. As used herein, the term "continuous" refers to a layer that covers the entire exposed surface without gaps or bare spots that expose material underlying the deposited layer. A continuous film may have gaps or bare spots, the surface area of ​​which is less than about 1% of the total surface area of ​​the film.

[0049] After the deposition process 220, the method 200 reaches a decision point 230. At the decision point 230, the fill condition of the feature is evaluated. If the feature 110 or gap has been completely filled, the method 200 can be stopped and the substrate can be subjected to optional post-processing 260. If the feature or gap has not been filled, the method 200 moves to an etching process 240.

[0050] In one or more embodiments, after the deposition process 220 but before the etching process 240, the substrate 100 is subjected to a purge process and / or a vacuum process. In some embodiments, between the deposition process 220 and the etching process 240, a purge gas such as argon is introduced into the process chamber to purge the reaction zone or otherwise remove any residual reactive compounds or byproducts from the reaction zone. In some embodiments, the purge gas flows into the process chamber continuously throughout the method 200. In some embodiments, between the deposition process 220 and the etching process 240, a negative pressure is applied to the process chamber to remove any residual reactive compounds or byproducts from the reaction zone. In some embodiments, the negative pressure is applied to the process chamber continuously throughout the method 200. In some embodiments, the purge process and / or the vacuum process is applied before the post-process 260.

[0051] In one or more embodiments, the etching process 240 etches a non-conformal film. In some embodiments, the etching process 240 etches a thickness T of the film 370 on the sidewalls of the feature 110 etched by the film 370 s Greater than the thickness T from the bottom of feature 110 b In one or more embodiments, the thickness T of the film 370 on the sidewalls of the feature 110 etched by the etching process is s Greater than the thickness T from the top of feature 110 t .

[0052] Without being bound by any particular theory of operation, it is believed that the directed plasma treatment preferentially modifies the top film 374 and the bottom film 372 relative to the sidewall film 376. The modified films appear to be more resistant to etching. This results in a higher sidewall etch rate thereafter. Figure 3B Feature 110 is shown having been subjected to a film etch resulting in modification of top film 384 and bottom film 382 in accordance with one or more embodiments of the present disclosure.

[0053] Figure 3C An etched film according to one or more embodiments of the present disclosure is shown. Etched film 370 removes substantially all of sidewall film 376 from feature 110, leaving behind some of top film 384 and bottom film 382. In some embodiments, removing substantially all of sidewall film 376 means that at least about 95%, 98%, or 99% of the surface area of ​​the sidewall has been etched. In some embodiments, removing substantially all of sidewall film 376 includes nucleation delay for subsequent deposition process 220.

[0054] In one or more embodiments, the etching process 240 includes exposing the substrate surface to one or more of an etching carrier gas or an etching reactant gas. In some embodiments, the second carrier gas includes one or more of argon (Ar), helium (He), or nitrogen (N2). In some embodiments, the second reactant gas includes one or more of Cl2, H2, NF3, or HCl. In some embodiments, the second reactant gas includes H2 or consists essentially of H2. In some embodiments, each of the second carrier gas or the second reactant gas is 40sccm to 10000sccm, 40sccm to 5000sccm, 40sccm to 2000sccm, 40sccm to 1000sccm, 40sccm to 500sccm, 40sccm to 100sccm, 100sccm to 10000sccm, 100sccm to 5000sccm, 100sccm to 2000sccm, 100sccm to 1000sccm. The oxygen-rich substrate may be independently flowed onto the substrate surface at a flow rate within the range of 100 sccm to 500 sccm, 250 sccm to 10000 sccm, 250 sccm to 5000 sccm, 250 sccm to 2000 sccm, 250 sccm to 1000 sccm, 250 sccm to 500 sccm, 500 sccm to 10000 sccm, 500 sccm to 5000 sccm, 500 sccm to 2000 sccm or 500 sccm to 1000 sccm.

[0055] In one or more embodiments, the etching process 240 includes maintaining the temperature of the substrate 100 at 15°C to 250°C, 15°C to 225°C, 15°C to 200°C, 15°C to 175°C, 15°C to 150°C, 15°C to 125°C, 15°C to 100°C, 25°C to 250°C, 25°C to 225°C, 25°C to 200°C, 25°C to 175°C, 25°C to 150°C, 25°C to In some embodiments, the substrate is maintained at a temperature in a range of 25° C. to 100° C., 50° C. to 250° C., 50° C. to 225° C., 50° C. to 200° C., 50° C. to 175° C., 50° C. to 150° C., 50° C. to 125° C., 50° C. to 100° C., 75° C. to 250° C., 75° C. to 225° C., 75° C. to 200° C., 75° C. to 175° C., 75° C. to 150° C., 75° C. to 125° C., or 75° C. to 100° C. In some embodiments, the substrate is maintained at the same temperature during the deposition process 220 and the etching process 240. In some embodiments, the substrate is maintained at different (ΔT>10° C.) temperatures during the deposition process 220 and the etching process 240.

[0056] In one or more embodiments, the etching process 240 includes maintaining the pressure of the substrate 100 in a range of 0.1 Torr to 12 Torr, 0.5 Torr to 12 Torr, 1 Torr to 12 Torr, 2 Torr to 12 Torr, 3 Torr to 12 Torr, 4 Torr to 12 Torr, 0.1 Torr to 10 Torr, 0.5 Torr to 10 Torr, 1 Torr to 10 Torr, 2 Torr to 10 Torr, 3 Torr to 10 Torr, 4 Torr to 10 Torr, 0.1 Torr to 8 Torr, 0.5 Torr to 8 Torr, 1 Torr to 8 Torr, 2 Torr to 8 Torr, 3 Torr to 8 Torr, 4 Torr to 8 Torr, 0.1 Torr to 5 Torr, 0.5 Torr to 5 Torr, 1 Torr to 5 Torr, 2 Torr to 5 Torr, 3 Torr to 5 Torr, or 4 Torr to 5 Torr.

[0057] In some embodiments, the etching process 240 includes an etching plasma. In some embodiments, the etching plasma is a conductive coupled plasma (CCP) or an inductively coupled plasma (ICP). In some embodiments, the etching plasma is a direct plasma or a remote plasma. In some embodiments, the etching plasma is operated at a power in the range of 0W to 500W, 50W to 500W, 50W to 400W, 50W to 300W, 50W to 200W, 50W to 100W, 100W to 500W, 100W to 400W, 100W to 300W, 100W to 200W, 200W to 500W, 200W to 400W, or 200W to 300W. In some embodiments, the minimum power of the plasma is greater than 0W.

[0058] In some embodiments, the etching process occurs at a continuous power level. In some embodiments, the etching process occurs with a second HFRF plasma pulse. In some embodiments, each of the plurality of second HFRF plasma pulses is independently generated at an etching power in the range of 0W to 500W, 50W to 500W, 50W to 400W, 50W to 300W, 50W to 200W, 50W to 100W, 100W to 500W, 100W to 400W, 100W to 300W, 100W to 200W, 200W to 500W, 200W to 400W, or 200W to 300W. In some embodiments, the minimum second plasma power is greater than 0W. In some embodiments, the power of the pulses is the same during the etching process. In some embodiments, the power of the pulses varies during the etching process.

[0059] In one or more embodiments, the plurality of second HFRF plasma pulses have a duty cycle in the range of 1% to 50%, 1% to 45%, 1% to 40%, 1% to 35%, 1% to 30%, 1% to 25%, 1% to 20%, 1% to 15%, 1% to 10%, 5% to 50%, 5% to 45%, 5% to 40%, 5% to 35%, 5% to 30%, 5% to 25%, 5% to 20%, 5% to 15%, 5% to 10%, 10% to 50%, 10% to 45%, 10% to 40%, 10% to 35%, 10% to 30%, 10% to 25%, 10% to 20%, or 10% to 15%. In some embodiments, the duty cycle of the pulses is the same during the etching process. In some embodiments, the duty cycle of the pulses varies during the etching process.

[0060] In one or more embodiments, each of the plurality of second HFRF plasma pulses has a pulse width in the range of 5 milliseconds to 50 microseconds, 4 milliseconds to 50 microseconds, 3 milliseconds to 50 microseconds, 2 milliseconds to 50 microseconds, 1 millisecond to 50 microseconds, 800 microseconds to 50 microseconds, 500 microseconds to 50 microseconds, 200 microseconds to 50 microseconds, 5 milliseconds to 100 microseconds, 4 milliseconds to 100 microseconds, 3 milliseconds to 100 microseconds, 2 milliseconds to 100 microseconds, 1 millisecond to 100 microseconds, 800 microseconds to 100 microseconds, 500 microseconds to 100 microseconds, and 200 microseconds to 100 microseconds. In some embodiments, the pulse widths of the pulses are the same during the etching process. In some embodiments, the pulse widths of the pulses vary during the etching process.

[0061] In one or more embodiments, each of the plurality of second HFRF plasma pulses independently has a pulse frequency in the range of 0.1 kHz to 20 kHz, 0.1 kHz to 15 kHz, 0.1 kHz to 10 kHz, 0.1 kHz to 5 kHz, 0.5 kHz to 20 kHz, 0.5 kHz to 15 kHz, 0.5 kHz to 10 kHz, 0.5 kHz to 5 kHz, 1 kHz to 20 kHz, 1 kHz to 15 kHz, 1 kHz to 10 kHz, 1 kHz to 5 kHz, 2 kHz to 20 kHz, 2 kHz to 15 kHz, 2 kHz to 10 kHz, or 2 kHz to 5 kHz. In some embodiments, the frequency of the pulses is the same during the etching process. In some embodiments, the frequency of the pulses varies during the etching process.

[0062] In one or more embodiments, the plurality of second HFRF pulses have an etching radio frequency in the range of 5 MHz to 20 MHz, 5 MHz to 15 MHz, 5 MHz to 10 MHz, 10 MHz to 20 MHz, or 10 MHz to 15 MHz. In one or more embodiments, the plurality of second HFRF pulses have a second radio frequency of 13.56 MHz. In some embodiments, the radio frequency of the pulses is the same during the etching process. In some embodiments, the radio frequency of the pulses varies during the etching process. In one or more embodiments, each of the plurality of second HFRF pulses independently has an etching radio frequency in the range of 5 MHz to 20 MHz, 5 MHz to 15 MHz, 5 MHz to 10 MHz, 10 MHz to 20 MHz, or 10 MHz to 15 MHz. In one or more embodiments, each of the plurality of second HFRF pulses independently has a second radio frequency of 13.56 MHz.

[0063] In one or more embodiments, the method 200 further includes repeating the deposition process 220 and the etching film 240 for gap filling. In some embodiments, each of the repeating deposition process 220 and the repeating etching film 240 includes HFRF plasma. In some embodiments, the gap filling is seamless. Figure 3D The feature 110 is shown as having been filled after multiple cycles through the deposition-etch-treat process.

[0064] In one or more embodiments, one or more additional effects further cause the etch rate of the non-conformal film on the sidewalls of the feature to be different from the etch rate of the non-conformal film on the bottom of the feature. In some embodiments, the one or more additional effects include: a nucleation rate of a material to be deposited on the substrate surface (e.g., Si), a property of the substrate surface that affects the nucleation rate of a material to be deposited on the substrate surface, or an etch rate of a material to be deposited on the substrate surface (e.g., Si).

[0065] Some embodiments include an optional post-treatment 260 process. Post-treatment 260 can be used to modify the film 370 to improve some parameters of the film. In some embodiments, post-treatment 260 includes annealing the film 370. In some embodiments, post-treatment 260 can be performed by in-situ annealing in the same processing chamber used for deposition 220 and / or etching 240. Suitable annealing processes include, but are not limited to, rapid thermal processing (RTP) or rapid thermal annealing (RTA), spike annealing or UV curing, or electron beam curing and / or laser annealing. The annealing temperature can be in the range of about 500°C to 900°C. The composition of the environment during annealing can include one or more of H2, Ar, He, N2, NH3, SiH4, etc. The pressure during annealing can be in the range of about 100 mTorr to about 1 atmosphere.

[0066] Some embodiments of the present disclosure relate to conformal PECVD liners depositing metal-doped carbon films using a pulsed HFRF plasma process.As used in this manner, "metal-doped carbon" and "metal carbide" may be used interchangeably to refer to films having metal and carbon atoms.

[0067] Some embodiments of the present disclosure relate to metal carbide (e.g., tungsten carbide) liners for dynamic random access memory (DRAM) devices. Some embodiments of the present disclosure relate to metal carbide liners for memory or logic applications. Some embodiments of the present disclosure relate to methods for forming metal carbide hard molds.

[0068] Conventional plasma enhanced chemical vapor deposition of tungsten carbide forms a "mushroom shaped" film at the top of narrow trenches and a very thin film at the sidewalls, resulting in a liner with poor conformality. Without being bound by any particular theory of operation, it is believed that the plasma cannot adequately penetrate into deep trenches, resulting in poor conformality. The current state of the art for tungsten carbide deposition is PECVD using a continuous HFRF plasma, but does not produce good conformality, with the thinnest / thickest film conformality being about 22% for trenches with a critical dimension (CD) of about 100 nm. The inventors surprisingly found that using pulsed HFRF, tungsten carbide conformality can be improved to 40% to 70% or more. In some embodiments, pulsed HFRF plasma increases conformality by a factor of 2 or more.

[0069] Figure 4A Another embodiment of the present disclosure is shown in which a metal carbide liner is formed using a pulsed HFRF plasma. The metal carbide liner of some embodiments is formed during a liner formation process 215 as part of method 200. In some embodiments, the metal carbide liner is formed as part of a method different from that shown in method 200.

[0070] In the illustrated embodiment, the electronic device 300 has a metal carbide film 470 formed on the substrate surface, sidewalls, and bottom of the feature 110. The film 470 deposited on the substrate will have a film thickness T on the sidewalls of the feature. s , with a film thickness T at the top of the feature (i.e., on the surface of the substrate) t , and has a film thickness T at the bottom of feature 110 b Metal carbide film 470 has a bottom surface 472 at the bottom of feature 110 , a sidewall surface 476 at the sidewall of feature 110 , and a top surface 474 on the top surface of feature 110 .

[0071] In some embodiments, film 470 is conformally formed on at least one feature. As used herein, the term "conformal" or "conformally" refers to a metal carbide layer that adheres to and uniformly covers an exposed surface, wherein the thickness of the film on the sidewalls is greater than or equal to 40% of the thickness of the film on the top / bottom of the feature. In some embodiments, the metal carbide film has a conformality in the range of 40% to 75%. In some embodiments, the metal carbide film has a conformality greater than or equal to 40%, 45%, 50%, 55%, 60%, 65%, or 70%. Film 470 has greater conformality than films formed without a pulsed plasma (i.e., a continuous plasma), which typically have a conformality less than or equal to 25%.

[0072] In some embodiments, before stopping deposition, film 470 is deposited to an average thickness in the range of 1 nm to 100 nm, 1 nm to 80 nm, 1 nm to 50 nm, 10 nm to 100 nm, 10 nm to 80 nm, 10 nm to 50 nm, 20 nm to 100 nm, 20 nm to 80 nm, or 20 nm to 50 nm. In some embodiments, film 470 is deposited to an average thickness in the range of 5 nm to 100 nm, 5 nm to 80 nm, 5 nm to 40 nm, 5 nm to 30 nm, or 10 nm to 30 nm.

[0073] The process parameters used to deposit film 470 may affect the film thickness at the sidewalls of the feature, the top of the feature, and / or the bottom of the feature. For example, specific precursors and / or reactive species, plasma conditions, temperature, etc. In some embodiments, the thickness T at the top of the feature t Greater than the thickness T at the sidewall of the feature s In some embodiments, the thickness T at the bottom of the feature b Greater than the thickness T at the sidewall of the feature s In some embodiments, the thickness T at the top of the feature t Greater than the thickness T at the bottom of the feature b In some embodiments, the thickness T at the bottom of the feature b Greater than the thickness T at the top of the feature t .

[0074] During the film deposition process, the substrate is exposed to one or more process gases and / or conditions that form the film 470. In some embodiments, the process gas flows into the processing area of ​​the processing chamber, and a pulsed HFRF plasma is formed by the process gas to deposit the film 470. The process gas of some embodiments includes a metal precursor and a carrier gas, and the carrier gas is ignited into a plasma by the HFRF power. In some embodiments, the metal precursor includes a metal halide or consists essentially of a metal halide. The term "consisting essentially of..." used in this manner means that the active substance of the metal precursor is greater than or equal to 95%, 98%, 99% or 99.5% of the substance described. In some embodiments, the metal halide includes fluorine atoms or consists essentially of fluorine atoms. In some embodiments, the metal halide includes chlorine atoms or consists essentially of chlorine atoms.

[0075] In some embodiments, the metal precursor comprises one or more of tungsten (W), molybdenum (Mo), or nickel (Ni). In some embodiments, the metal precursor comprises tungsten hexafluoride (WF6) or consists essentially of tungsten hexafluoride (WF6). In some embodiments, the metal precursor comprises molybdenum (V) fluoride (MoF5) or consists essentially of molybdenum (V) fluoride (MoF5). In some embodiments, the metal precursor comprises nickel (II) fluoride (NiF2) or consists essentially of nickel (II) fluoride (NiF2). In some embodiments, the metal precursor comprises one or more of tungsten hexafluoride, molybdenum pentafluoride, or nickel difluoride or consists essentially of one or more of tungsten hexafluoride, molybdenum pentafluoride, or nickel difluoride.

[0076] In one or more embodiments, the linear pulsed HFRF plasma is a conductively coupled plasma (CCP) or an inductively coupled plasma (ICP). In some embodiments, the linear pulsed HFRF plasma is a direct plasma or a remote plasma. In some embodiments, each of the plurality of linear HFRF pulses is independently generated at a linear power in the range of 500 W to 1500 W, or in the range of 600 W to 1400 W, or in the range of 700 W to 1300 W, or in the range of 800 W to 1200 W. In some embodiments, the minimum liner plasma power is greater than 500 W. In some embodiments, all linear pulses have the same power. In some embodiments, the power of individual pulses in the liner HFRF plasma varies.

[0077] In one or more embodiments, the plurality of liner HFRF plasma pulses have a liner duty cycle of up to and including 99%. In some embodiments, the plurality of liner HFRF plasma pulses have a liner duty cycle in the range of 1% to 95%, 1% to 90%, 1% to 85%, 1% to 80%, 1% to 75%, 1% to 70%, 1% to 65%, 1% to 60%, 1% to 55%, 5% to 95%, 5% to 90%, 5% to 85%, 5% to 80%, 5% to 75%, 5% to 70%, 5% to 65%, 5% to 60%, 5% to 55%, 10% to 95%, 10% to 45%, 10% to 40%, 10% to 35%, 10% to 30%, 10% to 25%, 10% to 20%, or 10% to 15%. In some embodiments, each of the plasma pulses during the liner deposition process has the same duty cycle. In some embodiments, the duty cycle varies during the liner deposition process.

[0078] In one or more embodiments, each of the plurality of linear HFRF plasma pulses independently has a pulse width in the following range: 5 milliseconds to 50 microseconds, 4 milliseconds to 50 microseconds, 3 milliseconds to 50 microseconds, 2 milliseconds to 50 microseconds, 1 millisecond to 50 microseconds, 800 microseconds to 50 microseconds, 500 microseconds to 50 microseconds, 200 microseconds to 50 microseconds, 5 milliseconds to 100 microseconds, 4 milliseconds to 100 microseconds, 3 milliseconds to 100 microseconds, 2 milliseconds to 100 microseconds, 1 millisecond to 100 microseconds, 800 microseconds to 100 microseconds, 500 microseconds to 100 microseconds, and 200 microseconds to 100 microseconds. In some embodiments, each of the pulse widths is the same during the deposition process. In some embodiments, the pulse width varies during the deposition process.

[0079] In one or more embodiments, each of the plurality of linear HFRF plasma pulses independently has a linear pulse frequency in the range of 0.1 kHz to 20 kHz, 0.1 kHz to 15 kHz, 0.1 kHz to 10 kHz, 0.1 kHz to 5 kHz, 0.5 kHz to 20 kHz, 0.5 kHz to 15 kHz, 0.5 kHz to 10 kHz, 0.5 kHz to 5 kHz, 1 kHz to 20 kHz, 1 kHz to 15 kHz, 1 kHz to 10 kHz, 1 kHz to 8 kHz, 1 kHz to 5 kHz, 2 kHz to 20 kHz, 2 kHz to 15 kHz, 2 kHz to 10 kHz, or 2 kHz to 5 kHz. In some embodiments, the pulse frequency remains the same during the deposition process. In some embodiments, the pulse frequency varies during the deposition process.

[0080] As part of method 200, liner formation process 215 occurs before deposition process 220 and may occur at any suitable substrate temperature. The substrate temperature during liner formation process 215 may be the same or different than the substrate temperature during deposition process 220 or etching 240.

[0081] In some embodiments, during the liner formation process 215 , the substrate is maintained at a liner temperature in the range of 200° C. to 550° C., 250° C. to 525° C., 300° C. to 500° C., 325° C. to 475° C., or 350° C. to 450° C.

[0082] In some embodiments, the liner formation process 215 includes a plasma enhanced chemical vapor deposition (CVD) process. In one or more embodiments, the liner formation process 215 includes flowing one or more of a carrier gas, a liner precursor, or a liner reactant onto the substrate surface. In some embodiments, the carrier gas includes, but is not limited to, argon (Ar), helium He, H2, or N2.

[0083] In one or more embodiments, each of the liner carrier gas, liner precursor gas, or liner reactant gas is independently flowed onto the substrate surface at a dosage in the range of 10 sccm to 500 sccm, 15 sccm to 350 sccm, 20 sccm to 200 sccm, 25 sccm to 150 sccm, or 50 sccm to 125 sccm.

[0084] In some embodiments, the liner formation process 215 produces a metal carbide film 470 having a tensile stress. In some embodiments, the tensile stress of the metal carbide film 470 is greater than or equal to 1 GPa, 1.25 GPa, 1.5 GPa, 1.75 GPa, or 2.0 GPa. The inventors have surprisingly discovered that the metal carbide film 470 formed using a pulsed HFRF plasma produces a film having a tensile stress, while typical metal carbide films formed by different processes have stresses ranging from low tensile stress (e.g., <1 GPa) to compressive stress (e.g., negative GPa).

[0085] After the liner formation process 215, the method 200 of some embodiments enters a cycle of film deposition 220, followed by a decision point 230 and an optional etching process 240 to form a seamless gap fill. Figure 4B As shown, in some embodiments, whether according to method 200 or by a different method, a gap-fill film 480 is formed in the feature 110 on the metal carbide liner 470 .

[0086] In some embodiments, the metal carbide liner 470 is removed from the top surface of the substrate, leaving the metal carbide liner 470 on the sidewalls of the feature 110. In some embodiments, the metal carbide liner 470 is removed from the top surface of the substrate and the bottom surface of the feature 110, leaving the metal carbide liner substantially only on the sidewalls of the feature.

[0087] According to one or more embodiments, the substrate 100 is processed before and / or after the layer is formed. Such processing can be performed in the same chamber or in one or more separate processing chambers. In some embodiments, the substrate 100 is moved from a first chamber to a separate second chamber for further processing. The substrate 100 can be moved directly from the first chamber to a separate processing chamber, or it can be moved from the first chamber to one or more transfer chambers and then to a separate processing chamber. Therefore, the processing equipment may include multiple chambers connected to a transfer station. This type of device may be referred to as a "cluster tool" or a "cluster system" or the like.

[0088] Typically, a cluster tool is a modular system that includes multiple chambers that perform various functions including substrate centering and orientation, degassing, annealing, deposition 220, and / or etching 240. According to one or more embodiments, the cluster tool includes at least a first chamber and a central transfer chamber. The central transfer chamber can house a robot that can shuttle substrates between and among process chambers and load lock chambers. The transfer chamber is typically maintained under vacuum conditions and provides an intermediate stage for shuttling substrates from one chamber to another and / or to a load lock chamber positioned at the front end of the cluster tool. Two well-known cluster tools that may be suitable for the present disclosure are and Both are available from Applied Materials, Inc., Santa Clara, California. The embodiments described herein may also be performed using other suitable systems. Other suitable systems include, but are not limited to XP Precision or its equivalent. However, the exact arrangement and combination of chambers may be varied in order to perform specific steps of the methods described herein. Other processing chambers that may be used include, but are not limited to, cyclic layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, chemical cleaning, thermal treatments (such as RTP), plasma nitridation, degassing, orientation, hydroxylation, and other substrate processes. By performing the processes in chambers on a cluster tool, surface contamination of the substrate with atmospheric impurities may be avoided without oxidation occurring prior to deposition of subsequent films.

[0089] According to one or more embodiments, the substrate 100 is continuously under vacuum or "load lock" conditions and is not exposed to ambient air when moving from one chamber to the next. Therefore, the transfer chamber is under a vacuum that is "pumped" at vacuum pressure. An inert gas may be present in the processing chamber or the transfer chamber. In some embodiments, the inert gas is used as a purge gas to remove some or all of the reactants. According to one or more embodiments, a purge gas is injected at the outlet of the deposition chamber to prevent reactants from moving from the deposition chamber to the transfer chamber and / or additional processing chambers. Therefore, the inert gas flow forms a curtain at the outlet of the chamber.

[0090] Substrates may be processed in a single substrate deposition chamber, where a single substrate is loaded, processed, and unloaded before processing another substrate. Similar to the conveyor system, substrates may also be processed in a continuous manner, where multiple substrates are individually loaded into a first portion of the chamber, moved through the chamber, and unloaded from a second portion of the chamber. The shape of the chamber and associated conveyor system may form a straight path or a curved path. Additionally, the processing chamber may be a turntable in which multiple substrates are moved around a central axis and exposed to deposition, etching, annealing, cleaning, etc. processes throughout the turntable path.

[0091] During processing, the substrate 100 may be heated or cooled. Such heating or cooling may be achieved by any suitable means, including but not limited to changing the temperature of the substrate support and flowing heated or cooled gas to the substrate surface. In some embodiments, the substrate support includes a heater / cooler that can be controlled to change the substrate temperature conductively. In one or more embodiments, the gas (reactive gas or inert gas) used is heated or cooled to locally change the substrate temperature. In some embodiments, the heater / cooler is positioned in a chamber adjacent to the substrate surface to change the substrate temperature convectively.

[0092] During processing, the substrate may also be stationary or rotated. The rotating substrate may be rotated continuously or in discrete steps. For example, the substrate may be rotated throughout the process, or the substrate may be rotated a small amount between exposures to different reactant gases or purge gases. Rotating the substrate during processing (continuously or in steps) may help produce a more uniform deposition or etching by minimizing the effects of local variability in, for example, gas flow geometry.

[0093] References throughout this specification to "one embodiment," "certain embodiments," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in conjunction with that embodiment is included in at least one embodiment of the present disclosure. Thus, phrases such as "in one or more embodiments," "in certain embodiments," "in an embodiment," or "in an embodiment" that appear in various places throughout this specification do not necessarily refer to the same embodiment of the present disclosure. Furthermore, in one or more embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner.

[0094] Although the disclosure herein has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrations of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations may be made to the method and apparatus of the disclosure without departing from the spirit and scope of the disclosure. Therefore, the disclosure is intended to include modifications and variations within the scope of the appended claims and their equivalents.

Claims

1. A gap filling method, the method comprising: A substrate having a substrate surface having a plurality of features formed in the substrate surface, each of the plurality of features extending a distance from the substrate surface into the substrate and having a bottom and at least one sidewall, is exposed to a deposition process including a pulsed high frequency radio frequency (HFRF) plasma having a plurality of HFRF pulses for depositing a liner. The liner comprises a metal carbide.

2. The method of claim 1, wherein the liner has a tensile stress greater than or equal to 1.5 GPa. 3 . The method of claim 1 , wherein each HFRF pulse of the plurality of HFRF pulses independently has a pulse frequency in the range of 1 kHz to 8 kHz. 4 . The method of claim 1 , wherein each of the plurality of HFRF pulses is independently generated at a power in the range of 500 W to 1500 W.

5. The method of claim 1, wherein the plurality of HFRF pulses have a duty cycle up to and including 99%.

6. The method of claim 1, wherein each of the HFRF pulses has a pulse width in the range of 1 millisecond to 100 microseconds.

7. The method of claim 1, wherein the deposition process comprises a plasma enhanced chemical vapor deposition (PECVD) process, the PECVD comprising flowing a metal precursor onto the substrate surface at a dose in a range of 20 sccm to 200 sccm.

8. The method of claim 1 further comprising filling the feature with a second material to cover the pad.

9. The method of claim 8, wherein the second material comprises amorphous silicon (a-Si).

10. The method of claim 1, wherein the liner has a thickness that varies in the range of 25% to 75% relative to an average thickness of the liner.

11. The method of claim 1, wherein the substrate is maintained at a pad temperature in the range of 300°C to 500°C.

12. The method of claim 1, wherein the deposition process is performed at a pressure in a range of 1 Torr to 10 Torr.

13. The method of claim 1, wherein the liner has a conformality in the range of 40% to 70%.

14. The method of claim 1, wherein the metal carbide film comprises tungsten carbide.

15. The method of claim 14, wherein the deposition process includes a metal precursor comprising tungsten hexafluoride (WF6).

16. A method of forming a liner using HFRF, the method comprising: A metal carbide liner is formed on sidewalls of a plurality of features formed in a substrate surface, each feature extending a distance into the substrate from the substrate surface and having at least one sidewall, the liner forming comprising exposing the substrate to a chemical vapor deposition process with a plurality of liner HFRF pulses.

17. The method of claim 16, wherein forming the metal carbide liner comprises exposing the substrate to a metal precursor comprising tungsten hexafluoride under the following conditions: a flow rate in the range of 20 sccm to 200 sccm, a temperature in the range of 300°C to 500°C, the plurality of liner HFRF pulses having a gapfill pulse frequency in the range of 1 kHz to 8 kHz, and a gapfill duty cycle up to and including 99% at a gapfill power in the range of 500 W to 1500 W.

18. The method of claim 16, further comprising filling the feature including the metal carbide liner with a second material via a gap fill deposition process.

19. The method of claim 18, wherein the gapfill deposition process comprises repeatedly depositing a non-conformal film in the feature and etching a portion of the non-conformal film, depositing the non-conformal film comprises a plurality of gapfill HFRF pulses, the plurality of gapfill HFRF pulses having a gapfill pulse frequency in a range of 1 kHz to 10 kHz at a gapfill radio frequency in a range of 5 MHz to 15 MHz and a gapfill duty cycle in a range of 1% to 20% at a gapfill power in a range of 50 W to 500 W, wherein each of the gapfill HFRF pulses has a gapfill pulse frequency in a range of 1 kHz to 10 kHz at a gapfill radio frequency in a range of 5 MHz to 15 MHz and a gapfill duty cycle in a range of 1% to 20% at a gapfill power in a range of 50 W to 500 W. 00 microseconds to 1 millisecond, and etching the non-conformal film includes exposing the non-conformal film to an etching plasma, the etching plasma including a plurality of etching HFRF pulses having an etching pulse frequency in a range of 1 kHz to 10 kHz at an etching radio frequency in a range of 5 MHz to 15 MHz and an etching duty cycle in a range of 1% to 20% at an etching power in a range of 100 W to 300 W, wherein each of the etching HFRF pulses has an etching pulse width in a range of 1 millisecond to 100 microseconds.

20. A method of forming a liner in a semiconductor device, the method comprising: A metal carbide liner is formed on sidewalls of a plurality of features formed in a surface of a substrate, each feature extending a distance from the substrate surface into the substrate and having at least one sidewall, wherein forming the metal carbide liner comprises exposing the substrate to a chemical vapor deposition process using one or more of a tungsten-containing precursor, a molybdenum-containing precursor, or a nickel-containing precursor and a plurality of liner HFRF pulses to form a metal carbide liner having a tensile stress.

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