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

Abstract

To provide a method for forming metal carbide liner in a feature formed on the surface of a substrate.SOLUTION: Each of features 110 extending at a certain distance from the surface of a substrate to the inside of the substrate includes a bottom and at least one side wall. A method for forming a metal carbide liner comprises depositing a metal carbide liner on the feature of the surface of the substrate by a plurality of high frequency radio frequency (HFRF) pulses; and provided are a semiconductor device including the metal carbide liner and a method for filling a gap using the metal carbide liner.SELECTED DRAWING: Figure 4A-4B

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 17 / 157,307, filed Jan. 25, 2021, the entire disclosure of which is incorporated herein by reference.

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

[0003] In the manufacture of microelectronic devices, many applications require the filling of narrow trenches with aspect ratios (AR) greater than 10:1 without voids. One application is shallow trench isolation (STI). This application requires films to be of high quality (e.g., with a wet etch rate ratio below 2) throughout the trench with very low leakage. One method that has been successful in the past is flowable CVD. In this method, oligomers are carefully formed in the gas phase, which condense on the surface and then "flow" into the trench. The as-deposited films are of very poor quality and require processing steps such as steam annealing and UV curing.

[0004] As feature dimensions shrink and aspect ratios increase, methods for post-curing deposited flowable films become challenging, resulting in films of varying composition throughout the filled trench.

[0005] Amorphous silicon is widely used in semiconductor manufacturing processes as a sacrificial layer since it can provide good etch selectivity over other films (e.g., silicon oxide, amorphous carbon, etc.). With the shrinking of critical dimensions (CD) in semiconductor manufacturing, filling high aspect ratio gaps becomes increasingly important in advanced wafer manufacturing. Current metal replacement gate processes include furnace polysilicon or amorphous silicon dummy gates. Due to the nature of the process, a seam forms in the center of the Si dummy gate. This seam can open during post-processing, resulting in structural defects.

[0006] Conventional plasma-enhanced chemical vapor deposition (PECVD) of amorphous silicon (a-Si) forms a "mushroom-shaped" film on the top of narrow trenches due to the inability of the plasma to penetrate into deep trenches, resulting in narrow trenches narrowing from the top and forming voids or seams at the bottom of the trench.

[0007] In conventional thermal CVD / furnace processes, a-Si can be grown by thermal decomposition of silicon precursors (e.g., silane, disilane). However, due to insufficient supply of precursors or the presence of decomposition by-products, the deposition rate at the top of the trench is higher than that at the bottom. Narrow seams or voids may be observed within the trench.

[0008] In addition, many semiconductor device applications incorporate 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 the top of narrow trenches and a very thin film on the sidewalls. This shaped film does not function as a conformal liner because the plasma cannot penetrate into deep trenches.

[0009] Therefore, there is a need for a method of forming a metal carbide conformal liner in a semiconductor device. Summary of the Invention

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

[0011] An additional embodiment of the present disclosure is directed to a method of forming a liner using HFRF. 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 liner includes exposing the substrate to a chemical vapor deposition process using a plurality of liner HFRF pulses.

[0012] A further embodiment of the present disclosure is directed to a method of forming a liner in a semiconductor device. 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 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 tensile stress.

[0013] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure, briefly summarized above, can be had by reference to embodiments, some of which are illustrated in the accompanying drawings, in which it is to be noted, however, that the accompanying drawings illustrate only typical embodiments of the present disclosure, and therefore should not be considered as limiting its scope, since the present disclosure may admit of other equally effective embodiments. [Brief description of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view of a substrate feature in accordance with one or more embodiments of the present disclosure; [Diagram 2] FIG. 1 illustrates a process flow according to one or more embodiments of the present disclosure. [Figure 3A-3D] 1 is a schematic cross-sectional view of a gap filling process according to one or more embodiments of the present disclosure. [Figure 4A-4B] 1 is a schematic cross-sectional view of a metal carbide liner formation process according to one or more embodiments of the present disclosure; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Before describing certain example embodiments of the present disclosure, it is to be understood that the present disclosure is not limited to the details of construction or process steps set forth in the following description as the present disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0016] As used herein, "substrate" refers to any substrate or material surface formed on a substrate on which a film treatment is performed during a manufacturing process. For example, substrate surfaces on which treatment can be performed include 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, depending on the application. Substrates include, but are not limited to, semiconductor wafers. Substrates can be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure, and / or bake the substrate surface. In addition to direct film treatment on the surface of the substrate itself, in this disclosure, any of the disclosed film treatment steps can also be performed on underlying layers formed on the substrate, as disclosed in more detail below, and the term "substrate surface" is intended to include such underlying layers as the context indicates. Thus, for example, if a film / layer or partial film / layer is being deposited on a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0017] One or more embodiments of the present disclosure provide a low-temperature silicon gap-fill process. By first depositing a silicon film and then etching the silicon film around some trench structures, a significantly thicker amorphous silicon (a-Si) film was produced at the bottom of the trench compared to the sidewalls or top of the trench. Some embodiments provide a method of cycling the deposition and etching to form a seamless silicon gap-fill.

[0018] 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 that include a cyclic deposition-etch-treatment process that can be performed in a cluster tool environment. Some embodiments advantageously provide seamless, doped or alloyed, high quality amorphous silicon films for filling high AR trenches with small dimensions.

[0019] FIG. 1 shows a partial cross-sectional view of a substrate 100 having a feature 110. Although the drawing shows a substrate with a single feature for illustrative purposes, one skilled in the art will understand that there may be more than one feature. The shape of the feature 110 may be any suitable shape, including, but not limited to, a trench and a cylindrical via. As used in this context, the term "feature" refers to any intentional surface irregularity. Suitable examples of features include, but are not limited to, a trench having a top, two sidewalls, and a bottom, and a peak having a top and two sidewalls. The feature may have any suitable aspect ratio (ratio of the depth of the feature to the width of the feature). In some embodiments, the aspect ratio is about 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, or 40:1 or more.

[0020] Substrate 100 has a substrate surface 120. At least one feature 110 forms an opening in substrate surface 120. Feature 110 extends to a depth D from substrate surface 120 to a 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 the bottom is also referred to as a gap.

[0021] During the gap-fill process, it is common for seams to form in the fill material. The size and width of the seams may affect the overall operability of the gap-fill component. The size and width of the seams may also be affected by the process conditions and the material being deposited. Thus, one or more embodiments advantageously provide a method for seamless (or void-free) gap-fill. Some embodiments of the method advantageously disclose a cyclic deposition-treatment-etch process for gap-fill. In some embodiments, the gap-fill is seamless.

[0022] 2 and 3A-3D illustrate an exemplary gap filling method 200 according to one or more embodiments of the present disclosure. In the embodiment illustrated in FIG. 2, the method 200 is performed on a substrate 100 having at least one feature 110. In some embodiments, the feature 110 has an aspect ratio of 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, or 40:1 or more. In some embodiments, the method 200 includes depositing 220 a film and etching 240 a film. In some embodiments, the film deposition 220 and / or the film etching 240 are performed in one or more processing chambers in a cluster tool environment. In some embodiments, the film deposition 220 and / or the 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.

[0023] Some embodiments advantageously provide a method to use plasma to etch material (e.g., Si) faster on the sidewalls of a feature than at the bottom of the feature. Some embodiments advantageously create bottom-up growth by repeating a deposition-etch process, using different etch rates on different surfaces and in different locations.

[0024] In the embodiment shown in FIG. 3A, a substrate 100 has features 110 formed thereon and two different surfaces, a first surface 350 and a second surface 360. The first surface 350 and the second surface 360 ​​can be different materials. For example, one of the surfaces may be a metal and the other a dielectric. In some embodiments, the first surface 350 and the second surface 360 ​​have the same chemical composition but different physical properties (e.g., crystallinity). In the method description below, reference to the substrate 100 refers to the first surface 350 and the second surface 360, or a single surface, on which the features 110 are formed.

[0025] 3A, feature 110 is formed by first surface 350 and second surface 360. The illustrated feature 110 is a trench, with first surface 350 forming the bottom of the feature and second surface 360 ​​forming the sidewalls and top.

[0026] In some embodiments, the method 200 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 modifies the surface termination. In some embodiments, the optional pretreatment 210 includes one or more of polishing, etching, reducing, oxidizing, hydroxylating, annealing, UV curing, e-beam curing, plasma treatment, and / or baking the substrate surface. In some embodiments, the plasma treatment includes NH3 plasma treatment.

[0027] In some embodiments, a liner is formed in feature 110 in a liner formation process 215. The liner formation process 215 is an optional process that may be included in method 200 or may be part of a separate method.

[0028] In the deposition process 220, a film 370 is deposited on the substrate 100. In one or more embodiments, depositing the film 370 comprises a plasma-enhanced chemical vapor deposition (PECVD) process or a plasma-enhanced atomic layer deposition (PEALD) process. In some embodiments, the deposition process 220 comprises a PECVD process. In some embodiments, the deposition process 220 comprises a PEALD process. In some embodiments, the PECVD comprises a gap-filling pulsed high frequency radio frequency (HFRF) plasma. In some embodiments, the gap-filling pulsed HFRF plasma comprises 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 various processes or components and is not intended to imply a particular order of processing or use.

[0029] As used herein, high frequency radio frequency plasma includes high frequency on / off power pulses. When on, the power is supplied at radio frequency. Pulse frequency and radio frequency refer to different aspects of the power used to generate the plasma that can be controlled independently.

[0030] The film 370 can be any suitable film that can be selectively deposited on the first surface 350 relative to the second surface 360. In some embodiments, the film 370 comprises silicon. In some embodiments, the film 370 consists essentially of silicon. When used in this manner, the term "consists essentially of" means that, on an atomic basis, about 90%, 93%, 95%, 98%, or 99% or more of the film is silicon (or the specified species). In some embodiments, the film 370 comprises amorphous silicon. In some embodiments, the film 370 comprises substantially only amorphous silicon. When used in this manner, the term "substantially only amorphous silicon" means that about 90%, 93%, 95%, 98%, or 99% or more of the film 370 is amorphous silicon.

[0031] 3A shows a film 370 formed on the substrate surface (top 374), the sidewalls 376 and the bottom 372 of the feature 110. The film 370 deposited on the substrate has a thickness T s , the film thickness T on top of the feature (i.e., on the surface of the substrate) t , and the thickness T b has.

[0032] In some embodiments, the film 370 is formed non-conformally on at least one feature. As used herein, the terms "non-conformal" or "non-conformal" refer to a layer that adheres to and covers an exposed surface non-uniformly with a thickness variation of more than 10% relative to the average thickness of the film. For example, a film having an average thickness of 100 Å will have a thickness variation of more than 10 Å. This thickness variation includes the edges, corners, sides, and bottom of the recess. In some embodiments, the variation is 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90% or more. In some embodiments, the film deposited on the sidewalls of the trench is thinner than the thickness of the film deposited on the bottom of the trench or the surface on which the trench is formed. In some embodiments, the average thickness of the film deposited on the sidewalls is no more than 90%, 80%, 70%, 60%, 50%, 40%, 30%, or 20% of the average thickness at the bottom and / or top of the trench.

[0033] In some embodiments, the film 370 is deposited until the average thickness is 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 before deposition is stopped. In some embodiments, the film 370 is deposited until the average thickness is 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.

[0034] The process parameters used to deposit film 370 can affect the film thickness on the sidewalls of the feature, the top of the feature, and / or the bottom of the feature, such as the particular precursor and / or reactive species, plasma conditions, temperature, etc. In some embodiments, the thickness T t is the thickness of the sidewall of the feature, T s In some embodiments, the thickness T of the bottom of the feature b is the thickness of the sidewall of the feature, T s In some embodiments, the thickness T t is the thickness T of the bottom of the feature b In some embodiments, the thickness T of the bottom of the feature b is the thickness T of the top of the feature t Greater than.

[0035] 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, the process gases flow into a processing region of the processing chamber and a pulsed HFRF plasma is formed from the process gases to deposit the film 370. The process gases in some embodiments include a silicon precursor and a carrier gas, which is ignited into a plasma by HFRF power.

[0036] 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 of the gap-filling pulses have the same power. In some embodiments, the individual pulse power of the gap-filling HFRF plasma is varied.

[0037] In one or more embodiments, the multiple gap-filling HFRF plasma pulses have 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, each of the plasma pulses in the gap-filling deposition process has the same duty cycle. In some embodiments, the duty cycle is varied during the gap-fill deposition process.

[0038] In one or more embodiments, each of the plurality of gap-filling HFRF plasma pulses independently has a pulse width in the range of 5 ms to 50 μs, 4 ms to 50 μs, 3 ms to 50 μs, 2 ms to 50 μs, 1 ms to 50 μs, 800 μs to 50 μs, 500 μs to 50 μs, 200 μs to 50 μs, 5 ms to 100 μs, 4 ms to 100 μs, 3 ms to 100 μs, 2 ms to 100 μs, 1 ms to 100 μs, 800 μs to 100 μs, 500 μs to 100 μs, and 200 μs to 100 μs. 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.

[0039] 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.

[0040] 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.

[0041] 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 is varied during the deposition process.

[0042] The deposition process 220 can be performed at any suitable substrate temperature. In some embodiments, during the deposition process 220, the substrate can be heated to a temperature between 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 ...50° C., 25° C. to 125° C., 25° C. to 100° C., 25° C. to 250° C., 25° C. to 225° C., 25° C. to 200° C., 25° C. to 150° C., 25° C. to The gap fill temperature is maintained in the range of 00°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.

[0043] 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, or consists essentially of, helium (He). 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, but is not limited to, silane, disilane, dichlorosilane (DCS), trisilane, or tetrasilane. In some embodiments, the precursor gas includes, but is not limited to, silane (SiH4). In some embodiments, the precursor gas includes, or consists essentially of disilane (Si2H6). In some embodiments, the precursor gas is heated in a high temperature canister to increase vapor pressure and delivered to the chamber using a carrier gas. In some embodiments, the first reactant gas includes H2.

[0044] In one or more embodiments, each of the gap fill carrier gas, precursor gas, or gap fill reactant gas may independently be at a flow rate of 40 sccm to 10,000 sccm, 40 sccm to 5,000 sccm, 40 sccm to 2,000 sccm, 40 sccm to 1,000 sccm, 40 sccm to 500 sccm, 40 sccm to 100 sccm, 100 sccm to 10,000 sccm, 100 sccm to 5,000 sccm, 100 sccm to 2,000 sccm, 100 sccm to 1 ...0 sccm, 100 sccm to 100000 sc m to 1000 sccm, 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.

[0045] In some embodiments, as shown in Figure 3A, 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 that have a surface area of ​​less than about 1% of the total surface area of ​​the film.

[0046] After the deposition process 220, the method 200 reaches a decision point 230, where the fill of the feature is evaluated. If the feature 110 or gap is completely filled, the method 200 may stop and the substrate may be subjected to an optional post-processing 260. If the feature or gap is not sufficiently filled, the method 200 proceeds to an etching process 240.

[0047] In one or more embodiments, after the deposition process 220 and before the etch process 240, the substrate 100 is subjected to a purge and / or vacuum treatment. In some embodiments, a purge gas, such as argon, is introduced into the processing chamber to purge the reaction zone or otherwise remove any residual reactive compounds or by-products from the reaction zone between the deposition process 220 and the etch process 240. In some embodiments, the purge gas is continuously flowed into the processing chamber throughout the method 200. In some embodiments, a negative pressure is applied to the processing chamber to remove any residual reactive compounds or by-products from the reaction zone between the deposition process 220 and the etch process 240. In some embodiments, a negative pressure is continuously applied to the processing chamber throughout the method 200. In some embodiments, a purge and / or vacuum treatment is applied before the post-processing procedure 260.

[0048] 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 from the bottom of the feature 110. b The thickness T of the film 370 on the sidewall of the feature 110 is larger than s In one or more embodiments, the etching process etches a thickness T from the top of the feature 110. t The thickness T of the film 370 on the sidewall of the feature 110 is larger than s Etch.

[0049] Without being bound to a particular theory of operation, it is believed that the directional plasma treatment preferentially modifies the top film 374 and bottom film 372 relative to the sidewall film 376. The modified films appear to be more etch resistant, which subsequently results in faster sidewall etch rates. Figure 3B illustrates the feature 110 that has been subjected to a film etch that results in modification of the top film 384 and bottom film 382 in accordance with one or more embodiments of the present disclosure.

[0050] 3C illustrates an etched film according to one or more embodiments of the present disclosure. Etching the film 370 removes substantially all of the sidewall film 376 from the feature 110, leaving a portion of the top film 384 and bottom film 382. In some embodiments, removing substantially all of the 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 the sidewall film 376 includes a delay in nucleation in the subsequent deposition process 220.

[0051] 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 reactive 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 reactive gas includes one or more of Cl2, H2, NF3, or HCl. In some embodiments, the second reactive gas includes or consists essentially of H2. In some embodiments, the second carrier gas or the second reactant gas each independently has a flow rate of 40 sccm to 10,000 sccm, 40 sccm to 5,000 sccm, 40 sccm to 2,000 sccm, 40 sccm to 1,000 sccm, 40 sccm to 500 sccm, 40 sccm to 100 sccm, 100 sccm to 10,000 sccm, 100 sccm to 5,000 sccm, 100 sccm to 2,000 sccm, 100 sccm to 10 The gas may be flowed over the substrate surface at a flow rate ranging from 00 sccm, 100 sccm to 500 sccm, 250 sccm to 10,000 sccm, 250 sccm to 5,000 sccm, 250 sccm to 2,000 sccm, 250 sccm to 1,000 sccm, 250 sccm to 500 sccm, 500 sccm to 10,000 sccm, 500 sccm to 5,000 sccm, 500 sccm to 2,000 sccm, or 500 sccm to 1,000 sccm.

[0052] In one or more embodiments, the etching process 240 may be performed by etching the substrate 100 at a temperature between 15° C. and 250° C., between 15° C. and 225° C., between 15° C. and 200° C., between 15° C. and 175° C., between 15° C. and 150° C., between 15° C. and 125° C., between 15° C. and 100° C., between 25° C. and 250° C., between 25° C. and 225° C., between 25° C. and 200° C., between 25° C. and 175° C., between 25° C. and 150° C., between 25° C. and 12 ... 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 etch process 240. In some embodiments, the substrate is maintained at different (ΔT>10° C.) temperatures during the deposition process 220 and the etch process 240.

[0053] In one or more embodiments, the etching process 240 includes maintaining the substrate 100 at a pressure in the 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.

[0054] In some embodiments, the etching process 240 includes an etching plasma. In some embodiments, the etching plasma is a conductively 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.

[0055] In some embodiments, the etching process is performed at a continuous power level. In some embodiments, the etching process is performed 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 is varied during the etching process.

[0056] 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 remains the same during the etching process. In some embodiments, the duty cycle of the pulses varies during the etching process.

[0057] In one or more embodiments, each of the plurality of second HFRF plasma pulses has a pulse width in the range of 5 ms to 50 μs, 4 ms to 50 μs, 3 ms to 50 μs, 2 ms to 50 μs, 1 ms to 50 μs, 800 μs to 50 μs, 500 μs to 50 μs, 200 μs to 50 μs, 5 ms to 100 μs, 4 ms to 100 μs, 3 ms to 100 μs, 2 ms to 100 μs, 1 ms to 100 μs, 800 μs to 100 μs, 500 μs to 100 μs, and 200 μs to 100 μs. In some embodiments, the pulse width of the pulses is the same during the etching process. In some embodiments, the pulse width of the pulses varies during the etching process.

[0058] 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.

[0059] In one or more embodiments, the plurality of second HFRF pulses 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, the plurality of second HFRF pulses has 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.

[0060] In one or more embodiments, the method 200 further includes repeating the deposition process 220 and the film etch 240 for gap filling. In some embodiments, each of the repetitions of the deposition process 220 and the film etch 240 includes an HFRF plasma. In some embodiments, the gap filling is seamless. Figure 3D shows the filled feature 110 after multiple repetitions of the deposition-etch-treatment process.

[0061] In one or more embodiments, one or more additional effects further differentiate the etch rate of a non-conformal film on the sidewalls of the feature from the etch rate of a 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 (e.g., Si) deposited on the substrate surface, a property of the substrate surface that affects the nucleation rate of a material deposited on the substrate surface, or an etch rate of a material (e.g., Si) deposited on the substrate surface.

[0062] Some embodiments include an optional post-treatment 260 process. The post-treatment 260 can be used to modify the film 370 and improve some parameters of the film. In some embodiments, the post-treatment 260 includes annealing the film 370. In some embodiments, the 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 anneal (RTA), spike anneal, or UV cure, or e-beam cure and / or laser anneal. The annealing temperature can range from 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 range from about 100 mTorr to about 1 atm.

[0063] Some embodiments of the present disclosure are directed to the deposition of conformal PECVD liners of metal-doped carbon films using pulsed HFRF plasma processes. As used in this manner, "metal-doped carbon" and "metal carbide" are used interchangeably to refer to films having metal and carbon atoms.

[0064] Some embodiments of the present disclosure are directed to metal carbide (e.g., tungsten carbide) liners for dynamic random access memory (DRAM) devices. Some embodiments of the present disclosure are directed to memory or logic applications of the metal carbide liners. Some embodiments of the present disclosure are directed to methods of forming a metal carbide hardmask.

[0065] Conventional plasma-enhanced chemical vapor deposition of tungsten carbide results in a "mushroom-shaped" film on the top of narrow trenches and a very thin film on the sidewalls, resulting in a poorly conformal liner. Without being bound to a particular theory of operation, it is believed that the plasma is unable to penetrate sufficiently into the deep trench, resulting in poor conformality. The current state of the art for tungsten carbide deposition is by PECVD using continuous HFRF plasma, but good conformality has not been achieved, with the thinnest / thickest film conformality being about 22% for trenches with critical dimensions (CD) of about 100 nm. The inventors have surprisingly found that the use of pulsed HFRF can improve the conformality of tungsten carbide from 40% to more than 70%. In some embodiments, the pulsed HFRF plasma increases conformality by more than a factor of two.

[0066] 4A illustrates another embodiment of the present disclosure in which a metal carbide liner is formed using a pulsed HFRF plasma. The metal carbide liner of some embodiments is formed during the liner formation process 215 as part of method 200. In some embodiments, the metal carbide liner is formed as part of a different method than that shown in method 200.

[0067] 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 has a thickness T s , the film thickness T on top of the feature (i.e., on the surface of the substrate) t , and the thickness T b The metal carbide film 470 has a bottom surface 472 at the bottom of the feature 110, a sidewall surface 476 at the sidewall of the feature 110, and a top surface 474 at the top surface of the feature 110.

[0068] In some embodiments, the film 470 is conformally formed on at least one feature. As used herein, the terms "conformal" or "conformally" refer to a metal carbide layer that adheres to and uniformly covers exposed surfaces with the thickness of the film on the sidewalls being 40% or more of the thickness of the film on the top / bottom of the feature. In some embodiments, the metal carbide film has a conformality ranging from 40% to 75%. In some embodiments, the metal carbide film has a conformality of 40%, 45%, 50%, 55%, 60%, 65%, or 70% or more. The film 470 has a higher conformality than films formed without a pulsed plasma (i.e., continuous plasma), which typically have a conformality of 25% or less.

[0069] In some embodiments, the 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 before deposition is stopped. In some embodiments, the 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.

[0070] The process parameters used to deposit film 470 can affect the film thickness on the sidewalls of the feature, the top of the feature, and / or the bottom of the feature, such as the particular precursor and / or reactive species, plasma conditions, temperature, etc. In some embodiments, the thickness T t is the thickness of the sidewall of the feature, T s In some embodiments, the thickness T of the bottom of the feature b is the thickness of the sidewall of the feature, T s In some embodiments, the thickness T t is the thickness T of the bottom of the feature b In some embodiments, the thickness T of the bottom of the feature b is the thickness T of the top of the feature t Greater than.

[0071] 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 gases flow into a processing region of the processing chamber and a pulsed HFRF plasma is formed from the process gases to deposit the film 470. The process gases of some embodiments include a metal precursor and a carrier gas, which is ignited into a plasma by HFRF power. In some embodiments, the metal precursor comprises or consists essentially of a metal halide. When used in this manner, the term "consists essentially of" means that the active species of the metal precursor are 95%, 98%, 99%, or 99.5% or more of the stated species. In some embodiments, the metal halide comprises or consists essentially of fluorine atoms. In some embodiments, the metal halide comprises or consists essentially of chlorine atoms.

[0072] 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 or consists essentially of tungsten hexafluoride (WF6). In some embodiments, the metal precursor comprises or consists essentially of molybdenum (V) fluoride (MoF5). In some embodiments, the metal precursor comprises or consists essentially of nickel (II) fluoride (NiF2). In some embodiments, the metal precursor comprises or consists essentially of one or more of tungsten hexafluoride, molybdenum pentafluoride, or nickel difluoride.

[0073] In one or more embodiments, the liner pulsed HFRF plasma is a capacitively coupled plasma (CCP) or an inductively coupled plasma (ICP). In some embodiments, the liner pulsed HFRF plasma is a direct plasma or a remote plasma. In some embodiments, each of the multiple liner HFRF pulses is independently generated at a liner power in the range of 500W to 1500W, or in the range of 600W to 1400W, or in the range of 700W to 1300W, or in the range of 800W to 1200W. In some embodiments, the minimum liner plasma power is greater than 500W. In some embodiments, all liner pulses have the same power. In some embodiments, the individual pulse power of the liner HFRF plasma varies.

[0074] In one or more embodiments, the multiple liner HFRF plasma pulses have a liner duty cycle of 99% or less, inclusive. In some embodiments, the multiple 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, hi some embodiments, the duty cycle varies during the liner deposition process.

[0075] In one or more embodiments, each of the plurality of liner HFRF plasma pulses independently has a pulse width in the range of 5 ms to 50 μs, 4 ms to 50 μs, 3 ms to 50 μs, 2 ms to 50 μs, 1 ms to 50 μs, 800 μs to 50 μs, 500 μs to 50 μs, 200 μs to 50 μs, 5 ms to 100 μs, 4 ms to 100 μs, 3 ms to 100 μs, 2 ms to 100 μs, 1 ms to 100 μs, 800 μs to 100 μs, 500 μs to 100 μs, and 200 μs to 100 μs. 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.

[0076] In one or more embodiments, each of the plurality of liner HFRF plasma pulses independently has a liner 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.

[0077] The liner formation process 215 is performed prior to the deposition process 220 as part of the method 200 and may be performed at any suitable substrate temperature. The substrate temperature during the liner formation process 215 may be the same or different than the substrate temperature during the deposition process 220 or during the etch 240.

[0078] 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.

[0079] 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 over the substrate surface. In some embodiments, the carrier gas includes, but is not limited to, argon (Ar), helium (He), H2, or N2.

[0080] In one or more embodiments, each of the liner carrier gas, liner precursor gas, or liner reactant gas is independently flowed over the substrate surface at a dosage ranging from 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.

[0081] In some embodiments, the liner formation process 215 results in a metal carbide film 470 having a tensile stress. In some embodiments, the tensile stress of the metal carbide film 470 is 1 GPa, 1.25 GPa, 1.5 GPa, 1.75 GPa, or 2.0 GPa or more. The inventors have surprisingly found that metal carbide films 470 formed using a pulsed HFRF plasma produce files with tensile stress, whereas 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).

[0082] After the liner formation process 215, the method 200 of some embodiments proceeds to a cycle of film deposition 220, followed by a decision point 230 and an optional etching process 240 to form a seamless gap fill. As shown in FIG. 4B, in some embodiments, a gap fill film 480 is formed in the features 110 on the metal carbide liner 470, whether according to the method 200 or a different method.

[0083] 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 features 110. In some embodiments, the metal carbide liner 470 is removed from the top surface of the substrate and the bottom surfaces of the features 110, leaving the metal carbide liner substantially only on the sidewalls of the features.

[0084] According to one or more embodiments, the substrate 100 is subjected to processing before and / or after the formation of the layer. This processing can be performed in the same chamber or in one or more separate processing chambers. In some embodiments, the substrate 100 is transferred from the first chamber to a separate second chamber for further processing. The substrate 100 may be transferred directly from the first chamber to the separate processing chamber or may be transferred from the first chamber to one or more transfer chambers and then to the separate processing chamber. Thus, the processing apparatus may include multiple chambers in communication with a transfer station. This type of apparatus may be referred to as a "cluster tool" or a "cluster system" or the like.

[0085] Generally, a cluster tool is a modular system with multiple chambers that perform various functions including center detection and orientation, degassing, annealing, deposition 220, and / or etching 240 of the substrate. 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 the processing chambers and the load lock chambers. The transfer chamber is typically maintained at reduced pressure and provides an intermediate stage that shuttles substrates from one chamber to another and / or to the load lock chamber located at the front end of the cluster tool. Two well-known cluster tools that may be compatible with the present disclosure are the Centura® and Endura®, both available from Applied Materials, Inc., Santa Clara, Calif., USA. The embodiments described herein may also be implemented using other suitable systems. Other suitable systems include, but are not limited to, Producer®, Producer® XP Precision, or equivalents. However, the exact arrangement and combination of chambers may be altered for purposes of performing specific steps of the processes described herein. Other processing chambers that can 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, alignment, hydroxylation, and other substrate processing. By performing processes in the chambers of a cluster tool, surface contamination of the substrate from atmospheric impurities can be avoided without oxidation prior to deposition of a subsequent film.

[0086] According to one or more embodiments, the substrate is under continuous vacuum or "load-locked" and is not exposed to ambient air as it moves from one chamber to the next. The transfer chamber is therefore under vacuum and is "pumped down" under vacuum. An inert gas may be present in the process 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, the purge gas is injected at the outlet of the deposition chamber to prevent the transfer of reactants from the deposition chamber to the transfer chamber and / or additional process chambers. Thus, a flow of inert gas forms a curtain at the outlet of the chamber.

[0087] Substrates can be processed in single substrate deposition chambers, where a single substrate is loaded, processed, and unloaded before another substrate is processed. Substrates can also be processed in a continuous manner, as with a conveyor system, 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 geometry of the chamber and associated conveyor system can form a linear or curved path. Additionally, the processing chamber can be a carousel, where multiple substrates move around a central axis and are exposed to processes such as deposition, etching, annealing, cleaning, etc. throughout the carousel path.

[0088] During processing, the substrate 100 can be heated or cooled. Such heating or cooling can be accomplished by any suitable means, including but not limited to changing the temperature of the substrate support and flowing a heated or cooled gas over the substrate surface. In some embodiments, the substrate support includes a heater / cooler that can be controlled to conductively change the substrate temperature. In one or more embodiments, the gas used (reactive or inert) is heated or cooled to locally change the substrate temperature. In some embodiments, a heater / cooler is positioned in the chamber adjacent to the substrate surface to change the substrate temperature by convection.

[0089] The substrate may also be stationary or rotating during processing. A rotating substrate may be rotated continuously or in discrete steps. For example, the substrate may be rotated throughout the entire process, or may be rotated only slightly between exposures to different reactive or purge gases. Rotating the substrate during processing (either continuously or in steps) can help achieve more uniform deposition or etching, for example, by minimizing the effects of local variations in gas flow geometry.

[0090] References throughout this specification to "one embodiment," "certain embodiment," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with an embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of phrases such as "in one or more embodiments," "in an embodiment," "in an embodiment," or "in an embodiment" in various places throughout this specification do not necessarily refer to the same embodiment of the disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0091] Although the disclosure of this specification has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method and apparatus without departing from the spirit and scope of the disclosure. Therefore, the disclosure is intended to cover modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

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

2. The method of claim 1 , wherein the liner has a tensile stress of 1.5 GPa or greater.

3. 10. The method of claim 1, wherein each of the plurality of HF RF pulses independently has a pulse frequency in the range of 1 kHz to 8 kHz.

4. 10. The method of claim 1, wherein each of the plurality of HF RF pulses is independently generated at a power in the range of 500 W to 1500 W.

5. 2. The method of claim 1, wherein the plurality of HF RF pulses have a duty cycle of less than or equal to 99%.

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

7. 10. 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 to the substrate surface at a dosage in the range of 20 sccm to 200 sccm.

8. The method of claim 1 , further comprising filling the features with a second material to cover the liner.

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, the thickness having a variation 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 liner temperature in the range of 300° C. to 500° C.

12. The method of claim 1 , wherein the deposition process is carried out at a pressure in the 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 deposition process uses tungsten hexafluoride (WF ６ 15. The method of claim 14, further comprising a metal precursor comprising:

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

17. 17. The method of claim 16, wherein forming the metal carbide liner comprises exposing the substrate to a metal precursor comprising tungsten hexafluoride at a flow rate ranging from 20 sccm to 200 sccm at a temperature ranging from 300° C. to 500° C., the plurality of liner HF RF pulses having a gap-filling pulse frequency ranging from 1 kHz to 8 kHz and a gap-filling duty cycle of up to and including 99% at a gap-filling power ranging from 500 W to 1500 W.

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

19. the gap-fill deposition process includes repeatedly depositing a non-conformal film in the feature and etching a portion of the non-conformal film, and depositing the non-conformal film includes a plurality of gap-fill HFRF pulses having a gap-fill pulse frequency in the range of 1 kHz to 10 kHz with a gap-fill duty cycle in the range of 1% to 20% at a gap-fill radio frequency in the range of 5 MHz to 15 MHz and a gap-fill power in the range of 50 W to 500 W, each of the gap-fill HFRF pulses having a gap-fill pulse duration in the range of 100 μsec to 1 millisecond.

20. The method of claim 18, wherein etching the non-conformal film comprises exposing the non-conformal film to an etching plasma comprising a plurality of etching HFRF pulses having an etching pulse frequency in the range of 1 kHz to 10 kHz, with an etching duty cycle in the range of 1% to 20% at an etching radio frequency in the range of 5 MHz to 15 MHz and an etching power in the range of 100 W to 300 W, each of the etching HFRF pulses having an etching pulse width in the range of 1 millisecond to 100 μsec.

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

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