Deposition with modification step for sputtering and / or composition modification

Abstract

Examples disclosed relate to chemical vapor deposition (CVD) with a plasma-based modification step. One example provides a method of performing CVD. The method includes performing a plurality of CVD cycles to form a silicon-containing film on a substrate. Each of the plurality of CVD cycles includes performing a CVD step by exposing the substrate to a gas stream of a silicon-containing precursor under conditions configured to convert the silicon-containing precursor into a silicon-containing film on the substrate. Each CVD cycle further includes performing a modification step after performing the CVD step, the modification step modifying at least a profile of the silicon-containing film or modifying a composition of the silicon-containing film by ion bombardment of the silicon-containing film using a plasma.

Description

Background Technology

[0001] Semiconductor device manufacturing processes involve multiple steps, including material deposition, patterning, and removal, to form integrated circuits on a substrate. Various methods can be used to deposit material films on a substrate. For example, chemical vapor deposition (CVD) deposits a film by guiding a continuously flowing precursor compound to the substrate under conditions that convert the precursor compound into a film. In various examples, the precursor compound can be converted into a film using thermal energy (thermal CVD) or plasma (plasma-enhanced CVD). Summary of the Invention

[0002] This invention is provided to introduce the chosen concepts in a simplified form, which will be further described in the following detailed description. This invention is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that address any or all the shortcomings mentioned in any part of this disclosure.

[0003] The disclosed examples relate to chemical vapor deposition (CVD) with a plasma-based modification step. One example provides a method for performing CVD. This method includes performing multiple CVD cycles to form a silicon-containing film on a substrate. Each of the multiple CVD cycles includes performing a CVD step by exposing the substrate to a gas stream of silicon-containing precursors under conditions configured to convert a silicon-containing precursor into a silicon-containing film on the substrate. Each CVD cycle also includes performing a modification step by bombarding the silicon-containing film with ions using plasma to at least modify the contour or composition of the silicon-containing film.

[0004] In some of these examples, the modification steps include forming a plasma with an inert gas to alter the profile of the concave structure of the silicon-containing film via sputtering.

[0005] In some such examples, the silicon-containing precursors alternatively or additionally include silane precursors, and the silicon-containing films include silicon oxide, silicon oxynitride, or silicon nitride.

[0006] In some such examples, the plasma alternative ground or additional ground of the modification step is formed using radio frequency energy including low-frequency energy components of 3 MHz or lower and high-frequency energy components of 3 MHz to 300 MHz.

[0007] In some such examples, the plasma alternative ground or additional ground for the CVD step is formed using radio frequency energy that includes high-frequency components from 3 MHz to 300 MHz and omits low-frequency components.

[0008] In some such examples, the silicon-containing film deposited in the CVD step is alternatively or additionally a silicon oxide film, wherein the silicon-containing precursor includes tetraethlyorthosilicate, and wherein the modification step includes nitriding the silicon oxide film.

[0009] In some such examples, the silicon oxide nitride film alternatively or additionally includes the use of one or more of ammonia, molecular nitrogen, hydrazine, or CN-containing substances to form plasma.

[0010] In some such examples, the modification steps alternatively or additionally include sputtering and modification of the composition of the silicon-containing film.

[0011] In some such examples, modifying the composition of the silicon-containing film includes nitriding the silicon-containing film.

[0012] In some such examples, the CVD step includes forming a silicon oxide, silicon oxynitride, or silicon nitride film using a silane precursor, and wherein modifying the composition of the silicon-containing film by nitriding the silicon-containing film includes silicon oxide, silicon oxynitride, or silicon nitride film.

[0013] In some such examples, this method alternatively or additionally includes performing a CVD loop that omits the modification step.

[0014] Another example provides a method for performing plasma-enhanced CVD. This method includes performing multiple CVD cycles. The CVD cycle within the multiple CVD cycles includes performing a CVD step by introducing a gas stream of tetraethoxysilane (TEOS) into a plasma to deposit a silicon oxide film on a substrate. The CVD cycle also includes, after performing the CVD step, performing a nitriding step by exposing the substrate to a plasma comprising a nitrogen source to nitrid the silicon oxide film, thereby forming a silicon oxynitride film.

[0015] In some of these examples, the nitrogen source includes one or more of nitrogen, ammonia, hydrazine, or CN-containing substances.

[0016] In some of these examples, the plasma alternative ground or additional ground containing a nitrogen source is formed using radio frequency power including low-frequency energy components of 3 MHz or lower and high-frequency energy components of 3 MHz to 300 MHz.

[0017] In some such examples, the silicon oxide or silicon oxynitride film alternatively or additionally includes nitrogen in an atomic percentage of up to 30%.

[0018] In some such examples, exposing the substrate to plasma alternatively or additionally includes a recessed structure for sputtering a silicon oxide film.

[0019] Another example provides a CVD tool. The CVD tool includes a processing chamber. The CVD tool also includes a substrate support disposed within the processing chamber. The CVD tool further includes flow control hardware configured to control the flow rate of gases flowing into the processing chamber from one or more gas sources. The CVD tool also includes a controller. The controller is configured to perform multiple CVD cycles, each of the multiple CVD cycles including a CVD step and a modification step. The controller is configured, in each CVD step, to operate the flow control hardware to introduce a silicon-containing precursor from a silicon-containing precursor source into the processing chamber, exposing the substrate to the silicon-containing precursor under conditions configured to convert the silicon-containing precursor into a silicon-containing film on the substrate. The controller is also configured, in each modification step, to operate the flow control hardware and an RF power supply to form a plasma to bombard the surface of the silicon-containing film with ions, thereby modifying at least the profile or composition of the silicon-containing film.

[0020] In some of these examples, the controller is configured to operate flow control hardware and radio frequency power to form plasma using an inert gas, thereby altering the profile of the silicon-containing recessed portion through sputtering.

[0021] In some such examples, the CVD tool alternatively or additionally includes a silicon-containing precursor source, including TEOS or silane, and the controller is also configured to operate flow control hardware and RF power supply during the modification step to modify the deposited silicon-containing film using one or more of argon, helium, nitrous oxide, ammonia, oxygen, or molecular nitrogen.

[0022] In some such examples, the CVD tool alternatively or additionally includes a silicon-containing precursor source, which includes silane, and the controller is also configured to operate flow control hardware and an RF power supply during a modification step to modify the deposited silicon-containing film using one or more of argon, helium, nitrous oxide, ammonia, or molecular nitrogen. Attached Figure Description

[0023] Figures 1A-1D schematically show the structures formed on a substrate in an exemplary chemical vapor deposition (CVD) process that leads to void formation.

[0024] Figure 2 shows a flowchart of an exemplary CVD process, which includes modification steps to sculpt the membrane and / or modify its composition.

[0025] Figure 3 shows a flowchart of an exemplary CVD process that includes modifying the composition of the deposited film.

[0026] Figure 4 shows a flowchart of an exemplary CVD process that includes a film layer deposited by sputtering engraving.

[0027] Figures 5A-5G show exemplary structures formed by using the CVD process of Figure 2 to perform gap filling while avoiding the formation of voids.

[0028] Figures 6A-6E show exemplary structures formed by depositing silicon oxide films using the CVD process of Figure 3 with tetraethoxysilane (TEOS) as a precursor.

[0029] Figures 7A-7F show exemplary structures formed using the CVD process of Figure 4 to perform silicon oxynitride gap filling with TEOS while avoiding the formation of voids.

[0030] Figure 8 shows a flowchart of an exemplary method for chemical vapor deposition with plasma-based modification steps.

[0031] Figure 9 schematically shows an exemplary CVD tool.

[0032] Figure 10 schematically shows a diagram of the computing system. Detailed Implementation

[0033] The term "aspect ratio" generally refers to the ratio between the depth of a feature and its average width.

[0034] The term "chemical vapor deposition" (CVD) generally refers to a process in which a solid-phase film is formed on a substrate by guiding a continuous flow of one or more precursor gases onto the substrate surface, under conditions configured to promote the chemical conversion of the precursor gases into a film. The term "plasma-enhanced chemical vapor deposition" (PECVD) generally refers to a CVD process in which plasma is used to promote the chemical conversion of one or more precursor gases into a solid-phase film on the substrate. Thermal CVD (TCVD) processes utilize thermal energy to promote film formation. The terms "growth," "deposition," and their variations can also be used to refer to film formation.

[0035] The term "CVD tool" generally refers to a machine that includes a processing chamber and other hardware configured to perform CVD processing.

[0036] The term "CVD cycle" generally refers to a multi-step process that can be repeated to form a film. A CVD cycle includes the CVD steps for depositing the film and modification steps for modifying the deposited film.

[0037] The term "CVD step" generally refers to the deposition of a film layer in a CVD cycle.

[0038] The term "flow control hardware" generally refers to components configured to fluidly connect one or more chemical sources to a processing chamber. For example, flow control hardware may include one or more mass flow controllers and / or valves. Exemplary chemical sources include membrane precursor sources, inert gas sources, and reactive gas sources, such as nitrogen and oxidant sources.

[0039] The term "gap" generally refers to a recessed structure on a substrate.

[0040] The term "modification step" generally refers to a process in a CVD cycle that involves at least physical or chemical modification of the deposited film.

[0041] The term "plasma" generally refers to a gas that consists of cations and free electrons.

[0042] The term "processing chamber" generally refers to an enclosure in which a substrate is chemically and / or physically treated. The pressure, temperature, and atmospheric composition within the processing chamber are controlled to facilitate chemical and / or physical treatment.

[0043] The term "nozzle" generally refers to a chemical outlet that includes multiple orifices distributed in an area.

[0044] The term "silicon-containing precursor" generally refers to any compound that can be introduced into a processing chamber in the gas phase to form a silicon-containing film on a substrate. Exemplary silicon-containing films include silicon oxide (SiO2), silicon nitride (Si3N4), and silicon oxynitride (SiO2). x N y ,0≤x≤2,0≤y≤1.33, hereinafter referred to as SiON), silicon carbide (SiC), silicon oxycarbonate (SiCxO2(1-x),0≤x≤1), silicon carbonitride (xSi3N4∙(1-x)SiC) and silicon oxycarbonate (SiO x C y N z (0≤x≤2, 0≤y≤1, 0≤z≤1.33). Exemplary silicon-containing precursors for forming silicon-containing films using CVD may include materials having the following general formula structure: R1, R2, and R3 can be the same or different substituents. In various examples, R1, R2, and R3 can include silanes, siloxy groups, amines, halides, hydrogen, or organic groups such as alkylamines, alkoxy groups, alkyl groups, alkenyl groups, alkynyl groups, and cyclic groups (e.g., aromatic groups).

[0045] Exemplary silicon-containing precursors include silanes and polysilanes (H3Si-(SiH2)). n-SiH3), where n≥0, for example, disilane, trisilane, and tetrasilane, as well as trisilylamine. Silanes and polysilanes are referred to herein as silanes or silane-based precursors. Silane-based precursors may include partially substituted and substituted variants of silanes and polysilanes.

[0046] In some examples, the silicon-containing precursor is an alkoxysilane. Usable alkoxysilanes include those with the general formula H0. x -Si-(OR) y Compounds in which x = 1-3, x + y = 4, and each R is a substituted or unsubstituted aliphatic or aromatic group; and H x (RO) y ,-Si-Si-(OR) y H x Each R is a substituted or unsubstituted aliphatic or aromatic group. Exemplary alkoxysilanes include tetramethoxysilane (TMOS), diethoxymethylsilane (DEMS), diethoxysilane (DES), dimethoxymethylsilane, dimethoxysilane (DMOS), methyl-diethoxysilane (MDES), methyl-dimethoxysilane (MDMS), t-butoxydisilane, triethoxysilane (TES), and trimethoxysilane (TMS or TriMOS).

[0047] In some examples, the silicon-containing precursor is a siloxane. Siloxanes include materials having Si-O-Si bonds. Exemplary siloxanes include octamethylcyclotetrasiloxane (OMCTS), octamethoxydodecasiloxane (OMODDS), and tetramethylcyclotetrasiloxane (TMCTS).

[0048] In some examples, the silicon-containing precursor is an aminosilane. Aminosilanes include those having the general formula H...x -Si-(NR) y The material, wherein x = 1-3, x + y = 4, and R is a substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aromatic or hydride group. Exemplary aminosilanes include bisdiethylaminosilane, diisopropylaminosilane, bis(t-butylamino)silane (BTBAS), di-sec-butylaminosilane, and tris(dimethylamino)silane (3DMAS).

[0049] In some examples, the silicon-containing precursor is a halogenated silane or a halogenated polysilane. Examples of halogenated silanes and halogenated polysilanes as silyl-based precursors are provided. In some examples, the halogenated silane may include at least one hydrogen atom. The general formula for such silanes is SiX. a H y , where y≥1. Examples of halogenated silanes include dichlorosilane (H2SiCl2), hexachlorodisilane (Si2Cl6), and diiodosilane (H2SiI2).

[0050] More specific examples of silicon-containing precursors include tetraethylorthosilicate (TEOS), methylsilane, trimethylsilane (3MS), ethylsilane, butylsilane, pentylsilane, octylsilane, heptylsilane, hexylsilane, cyclobutylsilane, cycloheptylsilane, cyclohexylsilane, cyclooctylsilane, cyclopentylsilane, 1,4-dioxa-2,3,5,6-tetrasilacyclohexane, triethoxysiloxane (TRIES), and tetraoxymethylcyclotetrasiloxane (TOMCTS).

[0051] In some examples, oxidants are used to react with silicon-containing precursors. Examples include molecular oxygen (O2), nitrous oxide (N2O), water (H2O), hydrogen peroxide (H2O2), and carbon dioxide (CO2).

[0052] An exemplary precursor for providing nitrogen to form a silicon oxynitride film is nitrous oxide (N₂O).

[0053] The term "sputtering" and its variations generally refer to the process in which ions in a plasma are accelerated toward a substrate with sufficient kinetic energy, causing at least some material on the substrate to be ejected from the substrate upon collision.

[0054] The term "sticking coefficient" generally represents the ratio of the amount of gaseous material adsorbed on the substrate surface to the amount of gaseous material impacting the substrate surface.

[0055] The term "substrate" generally refers to any object on which a film can be deposited.

[0056] The term "substrate support" generally refers to any structure used to support a substrate in a processing chamber.

[0057] As described above, chemical vapor deposition (CVD) uses a continuous flow of precursor compounds to deposit films on a substrate. Plasma-enhanced CVD (PECVD) utilizes plasma to promote the chemical transformation of precursor compounds to form films on a substrate. Thermal CVD (TCVD) processes utilize thermal energy to promote film formation.

[0058] Semiconductor device manufacturing may involve etching gaps into a substrate. In a process called gap filling, another material can be used to fill these gaps. PECVD is often used to fill gaps with dielectric materials such as silicon oxide. However, reentrancy can form during PECVD gap filling. Reentrancy narrows the opening of the gap. This increases the difficulty of gap filling because the precursor gas cannot enter a narrower gap as easily as a wider gap. Eventually, the gap closes at the reentrancy, forming a void.

[0059] Figures 1A-1D schematically illustrate the structures in an exemplary PECVD gap-filling process that leads to the formation of voids. Figure 1A shows a substrate 100 including gap 102. Substrate 100 may comprise any suitable material. Figure 1B shows a silicon oxide film 104 deposited on substrate 100 (including within gap 102) by PECVD. PECVD can deposit more silicon oxide in the upper region of the gap sidewalls (closer to the gap opening) than in the lower region of the gap inner sidewalls (further into the gap). This is because the adhesion coefficient of silicon oxide precursors (e.g., tetraethoxysilane (TEOS)) or silyl precursors favors top-heavy deposition. Therefore, the silicon oxide film grows faster in the upper region of the gap sidewalls than in the lower region. As shown in Figure 1B, this results in the silicon oxide film 104 growing thicker in the upper region 106 of gap 102 than in the lower sidewall 108. This closes the gap before it is completely filled. Although silicon film 104 in this example includes a silicon oxide film, other films can also be deposited in a top-heavy manner during the PECVD process. Other examples of silicon-containing films include silicon nitride, silicon oxynitride, silicon carbide, silicon carbide, silicon carbonitride, and silicon carbonitride.

[0060] Figure 1C shows the silicon oxide film 104 after further growth. Due to the faster growth rate of the upper sidewalls, a recessed structure 110 is formed on the silicon oxide film 104. The recessed structure 110 narrows the opening of the gap 102. A narrower gap opening increases the difficulty of filling the gap. Figure 1D shows the substrate 100 after further growth of the silicon oxide film 104. Due to the presence of the recessed structure 110, the gap 102 closes before being fully filled. This forms a void 112. As shown in Figure 1D, the top of the void 112 is higher than the top surface 114 of the substrate 100. Therefore, etching the silicon oxide film 104 to expose the substrate 100 will open the void 112. This can cause problems in subsequent fabrication steps. Void formation is particularly problematic for smaller features and features with higher aspect ratios (e.g., features with an aspect ratio of 0.5:1 or greater).

[0061] Atomic layer deposition (ALD) is a feasible method to avoid void formation during interstitial filling processes. ALD involves sequentially adsorbing a precursor onto a substrate and then chemically converting the adsorbed precursor into the desired film in a self-limiting step, thereby forming one or more independent films on the substrate. In this way, ALD can be used to deposit conformal films in a layer-by-layer process, thus avoiding void formation. However, compared to CVD, ALD is more expensive and slower. Another interstitial filling method is spin-on deposition (SOD) of liquid-phase precursor solutions. However, SOD can produce films of lower quality than PECVD films. For example, SOD films have lower thermal stability and are more prone to breakage compared to PECVD films.

[0062] Therefore, the disclosed examples relate to a cyclic CVD process that addresses these problems of current CVD processes. In short, the CVD process comprises multiple deposition cycles. Each deposition cycle includes a deposition step using CVD to deposit a silicon-containing film. After performing the deposition step, the deposition cycle includes a plasma-based modification step. The plasma-based modification step includes at least physical or chemical modification of the deposited film. In some examples, the modification step includes at least forming a plasma to sculpt the silicon-containing film via sputtering. In other examples, the modification step includes at least forming a plasma to modify the composition of the silicon-containing film. In further examples, the modification step includes shaping and composition modification.

[0063] Sputtering can be used to modify steps, such as sculpting the film to remove concave structures in the gaps. This enlarges the opening of the gap. Enlarging the opening allows a deposition process to fill the interior of the gap. Examples of deposition and modification steps are detailed below. By sculpting the CVD film to remove concave structures, deposition cycles can be repeated to fill the gaps without pinching off the opening. Thus, the disclosed examples provide void-free gap filling using CVD, a technique not limited to low aspect ratios, such as less than 0.5:1. This offers cost and / or time savings compared to other gap filling processes (e.g., ALD). Furthermore, gap filling can use PECVD to deposit films that are less prone to breakage and more thermally stable than films grown via SOD.

[0064] Individual processing conditions can be adjusted to control the sputtering intensity in the modification steps of the deposition cycle. As an example, the modification steps can be performed using a plasma with a higher frequency radio frequency energy component (“HF component”) and a lower frequency radio frequency energy component (“LF component”). The HF component can include frequencies from 3 MHz to higher (e.g., 3 MHz to 300 MHz). Examples include 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. The LF component can include frequencies from 3 MHz to lower. Examples include 2 MHz and 400 kHz. Using the LF component of radio frequency energy in addition to the HF component provides a higher sputtering rate than in examples where the LF component is omitted. As another example, increasing the power of the HF component helps increase the concentration of inert gas ions in the plasma, thereby increasing the sputtering rate. As a further example, increasing the power of the LF component increases the kinetic energy of the inert gas ions in the plasma, thereby helping to increase the sputtering rate. As yet another example, using a relatively lower pressure can provide a higher sputtering rate than using a relatively higher pressure, because the lower pressure provides a longer mean free path for ions in the plasma.

[0065] As described above, various silicon-containing precursors can be used in CVD processes to deposit silicon-containing films. Exemplary silicon-containing films include silicon oxide (SiO2) films and silicon oxynitride (SiON) films. These materials are commonly used as dielectric films in integrated circuits. An example of a silicon-containing film precursor is tetraethoxysilane (TEOS, Si(OC2H5)4). In the TEOS molecule, the central Si atom is bonded to four oxygen atoms. TEOS reacts with molecular oxygen (O2) in a plasma environment to form a high-quality silicon oxide film. TEOS can be used to deposit films with good conformability and low carbon content. Furthermore, TEOS is a relatively low-cost precursor. Therefore, TEOS is commonly used for silicon oxide deposition in CVD. However, using TEOS to deposit other films (such as silicon oxynitride) can be challenging. For example, CVD using TEOS and nitrogen-containing precursors does not significantly form silicon oxynitride. This is because the Si-O bond is thermodynamically more favorable than the Si-N bond. Therefore, the CVD process used to deposit silicon oxynitride films via CVD will use other precursors, such as a mixture of silane (SiH4), ammonia (NH3) and nitrous oxide (N2O).

[0066] Therefore, the disclosed examples also involve using TEOS as a precursor to form a silicon oxynitride film in a cyclic CVD process. In short, TEOS is used in the deposition step of a CVD cycle to deposit a silicon oxide film layer. Then, in a modification step, a plasma is formed using a nitrogen source, such as ammonia, molecular nitrogen (N2), hydrazine (N2H4), and / or a CN-containing substance (e.g., hydrogen cyanide (HCN) or a suitable nitrile). The high-energy nitrogen ions formed in the plasma bombard the silicon oxide film layer to break Si-O bonds and form Si-N bonds. This forms a silicon oxynitride layer. The deposition cycle is repeated to sequentially deposit and nitrid more silicon oxide layers, thereby forming a silicon oxynitride film. Therefore, the CVD process allows the use of TEOS as a precursor to form a silicon oxynitride film. As mentioned above, TEOS is relatively inexpensive and produces high-quality silicon oxide films. Therefore, the disclosed examples offer cost savings compared to other silicon oxynitride deposition methods. Furthermore, the nitrogen concentration in the silicon oxynitride film can be adjusted by controlling various conditions in the modification step. For example, a relatively long nitriding step can be used to increase the nitrogen concentration in the silicon oxynitride film compared to a relatively short nitriding step. The disclosed examples can be implemented in a processing tool configured to perform CVD using TEOS.

[0067] In some examples, the modification steps of the deposition cycle may simultaneously include physical modifications by sputtering and chemical modifications by nitriding. This can be used to deposit silicon oxynitride in a CVD gap-filling process using TEOS. In such an example, TEOS is used as a precursor in the deposition step to deposit a silicon oxide film in the gaps on the substrate. The modification step then involves forming a plasma using a gas mixture comprising a nitrogen source (e.g., molecular nitrogen, ammonia, hydrazine) or a CN-containing substance (e.g., hydrogen cyanide). Furthermore, the modification step is performed using plasma conditions configured to sputter the deposited silicon-containing film. In this way, the modification step preferentially sputters the recessed structures in the gaps and nitrids the silicon oxide film, thereby forming a silicon oxynitride film layer in the gaps. The deposition and modification steps can be repeated in any suitable deposition cycle to fill the gaps with silicon oxynitride without forming voids. Exemplary deposition cycles will be described in detail below. It will be understood that SiON films formed in other ways besides nitriding the oxide deposited by TEOS can also be etched by sputtering. For example, silanes, ammonia, and nitrous oxide can be used as precursors to deposit silicon oxynitride films using PECVD. Other silane precursors and / or other nitrogen-containing precursors can also be used. After depositing the silicon oxynitride film, the film can be etched by performing modification steps. Modification steps include forming a plasma to sputter the silicon oxynitride film. Then, one or more additional CVD cycles can be performed. In this way, silane precursors can be used to perform silicon oxynitride gap filling without creating voids.

[0068] Figures 2-4 show flowcharts illustrating example methods for depositing films using cyclic CVD processing. Figure 2 shows a method 200 in which a modification step of the cyclic CVD process is used to modify both the composition and shape of the film layer. Figure 3 illustrates a method in which a modification step of the cyclic CVD process is used to modify the composition of the film layer (in this example, by nitriding). Figure 4 illustrates a method 400 in which a modification step of the cyclic CVD process is used to sculpt the film layer.

[0069] Referring first to Figure 2, method 200 includes executing multiple CVD cycles 202. CVD cycle 202 includes executing CVD step 204 and executing modification step 210. As described below, modification step 210 may be omitted in some CVD cycles during the CVD process.

[0070] CVD step 204 includes exposing the substrate to the silicon-containing precursor under conditions configured to convert the silicon-containing precursor into a silicon-containing film. Exemplary silicon-containing films include silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbide, silicon carbonitride, and silicon carbonitride. Any suitable silicon-containing precursor can be used. In some examples, at 206, TEOS is introduced into a plasma to deposit silicon oxide via PECVD. As mentioned above, TEOS is relatively inexpensive and can be used to form high-quality silicon oxide films using PECVD. In some examples, TEOS is deposited together with an oxidant (e.g., nitrous oxide or molecular oxygen). Furthermore, the silicon oxide film layer deposited using the TEOS precursor can be modified by nitriding, as described below. Another example of a silicon-containing precursor is a silane.

[0071] Further examples of using CVD to form silicon-containing precursors for silicon-containing films may include materials having the following general formula structure: R1, R2, and R3 can be the same or different substituents. In various examples, R1, R2, and R3 may include silanes, siloxy groups, amines, halides, hydrogen, or organic groups such as alkylamines, alkoxy groups, alkyl groups, alkenyl groups, alkynyl groups, and cyclic groups (e.g., aromatic groups).

[0072] In some examples, the silicon-containing precursor is an alkoxysilane. Usable alkoxysilanes include those with the general formula H0. x -Si-(OR) y Compounds in which x = 1-3, x + y = 4, and each R is a substituted or unsubstituted aliphatic or aromatic group; and H x (RO) y ,-Si-Si-(OR) y H xEach R is a substituted or unsubstituted aliphatic or aromatic group. Exemplary alkoxysilanes include tetramethoxysilane (TMOS), diethoxymethylsilane (DEMS), diethoxysilane (DES), dimethoxymethylsilane, dimethoxysilane (DMOS), methyldiethoxysilane (MDES), methyldimethoxysilane (MDMS), t-butoxydisilane, triethoxysilane (TES), and trimethoxysilane (TMS or TriMOS).

[0073] In some examples, the silicon-containing precursor is a siloxane. Siloxanes include materials having Si-O-Si bonds. Exemplary siloxanes include octamethylcyclotetrasiloxane (OMCTS), octamethoxydodecylsiloxane (OMODDS), and tetramethylcyclotetrasiloxane (TMCTS).

[0074] In some examples, the silicon-containing precursor is an aminosilane. Aminosilanes include those having the general formula H... x -Si-(NR) y The material, wherein x = 1-3, x + y = 4, and R is a substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aromatic or hydride group. Exemplary aminosilanes include bis(diethylaminosilane), diisopropylaminosilane, bis(tert-butylamino)silane, disec-butylaminosilane, and tris(dimethylamino)silane (3DMAS).

[0075] In some examples, the silicon-containing precursor is a silane-containing precursor. In some such examples, the silane-containing precursor is partially or completely halogenated. The general formula for such silanes is SiX. a H y , where y≥0. Exemplary halosilanes include dichlorosilane (H2SiCl2), hexachlorodisilane (Si2Cl6), and diiodosilane (H2SiI2).

[0076] More specific examples of silicon-containing precursors include silanes, polysilanes (Si... n H 2n+2 Where n≥1, for example, disilane, trisilane and tetrasilane), trisilamine, methylsilane, trimethylsilane (3MS), ethylsilane, butylsilane, pentylsilane, octylsilane, heptylsilane, hexylsilane, cyclobutylsilane, cycloheptylsilane, cyclohexylsilane, cyclooctylsilane, cyclopentylsilane, 1,4-dioxa-2,3,5,6-tetrasilacyclohexane, triethoxysiloxane (TRIES), and tetraoxomethylcyclotetrasiloxane (TOMCTS).

[0077] As described in the TEOS example above, an oxidant can be used in the CVD process to react with a silicon-containing precursor. Examples include molecular oxygen, nitrous oxide, water, hydrogen peroxide, and carbon dioxide. Nitrous oxide is an example precursor that provides nitrogen to form a silicon oxynitride film. Furthermore, when using TEOS, according to the examples described herein, a silicon oxynitride film can be formed by performing a modified step including nitriding.

[0078] As described above, in some examples, silicon-containing membranes include carbon. Examples of such silicon-containing membranes include silicon carbide, silicon carbide, silicon carbonitride, and silicon carbonitride. Examples of carbon-containing precursors forming such membranes include alkanes, alkenes, alkynes, cyclic hydrocarbons, aromatics, alkyl halides, alkylamines, and alkyldiamines. More specific examples include acetylene and propylene.

[0079] In some examples, thermal CVD can be used as CVD step 204. In such examples, CVD step 204 includes heating the substrate to convert the silicon-containing precursor into a silicon-containing film. Examples of temperatures for thermal CVD processing include 500ºC to 1200ºC. In other examples, temperatures outside this range may also be used.

[0080] In other examples, PECVD can be used as CVD step 204. In such examples, a plasma is formed to facilitate the chemical conversion of the silicon-containing precursor into a silicon-containing film (i.e., the PECVD process). For example, TEOS can be introduced into the plasma at 206. Exemplary plasma conditions include RF power from 50 watts to 6000 watts (W). Exemplary frequencies of the RF plasma include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the plasma may include an HF component of RF energy and an LF component of RF energy. The HF component may include frequencies from 3 MHz to 300 MHz. The LF component may include frequencies of 3 MHz and below. The HF component may include RF power from 50 W to 6000 W. The LF component may include RF power from 0 W to 3000 W.

[0081] In some examples, using relatively low-power radio frequency (RF) energy can facilitate the deposition of relatively low-density silicon-containing films. Relatively low-density silicon-containing films are easier to nitrid or otherwise modify in composition than relatively high-density silicon-containing films. Furthermore, relatively low-density silicon-containing films are easier to etch by sputtering compared to relatively high-density films. Therefore, in some examples, the CVD step includes forming a plasma using RF power ranging from 50 W to 4000 W. In some more specific examples, RF power ranging from 100 W to 1000 W can be used. Additionally, CVD step 204 can be performed at any suitable pressure. Examples include pressures from 0.5 Torr to 20 Torr.

[0082] CVD step 204 can be performed for any suitable duration. In some examples, CVD step 204 is performed to deposit a silicon-containing film layer comprising a thickness of 1 nm to 10 nm. In a more specific example, the silicon-containing film layer may comprise a thickness of approximately 3 nm. In other examples, each film layer may comprise any other suitable thickness.

[0083] After performing CVD step 204, method 200 includes determining at 208 whether to perform a modification step. If a modification step is to be performed, method 200 proceeds to 210 to perform the modification step. Otherwise, for the selected CVD cycle, modification step 210 can be omitted.

[0084] Modification step 210 includes using plasma to bombard the silicon-containing film with ions. Modification step 210 includes at least physical or chemical modification of the silicon-containing film. As shown at 212, bombarding the silicon-containing film with ions can be used to modify the profile of the silicon-containing film. Furthermore, as shown at 214, bombarding the silicon-containing film with ions can be used to modify the composition of the silicon-containing film. Exemplary processes including step 212 are schematically shown in Figures 5A-5G. Exemplary processes including step 214 are schematically shown in Figures 6A-6E. Furthermore, exemplary processes including steps 212 and 214 are schematically shown in Figures 7A-7F. These examples will be described in detail below.

[0085] Modifying the film profile at 212 involves using an inert gas to form a plasma to sputter at least a portion of the silicon-containing film. This reduces the concave structure of the silicon-containing film. Any suitable inert gas can be used. Examples include Ar, He, Ne, Kr, and Xe. Any suitable sputtering conditions can be used. Examples of suitable pressures include pressures from 0.5 Torr to 5 Torr. Examples of suitable temperatures include temperatures from 250ºC to 650ºC. In some examples, the silicon-containing precursor flows into the processing chamber via a nozzle to react with the substrate on a substrate support. In some such examples, the substrate support is heated to a first temperature, and the nozzle may be heated to a second temperature. For example, the nozzle may be heated to a second temperature lower than the first temperature.

[0086] Any suitable plasma conditions can be used to sputter films. Exemplary frequencies for radio frequency (RF) plasmas include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the plasma is formed using both the HF and LF components of RF energy. In more specific examples, a 27 MHz HF component and a 400 kHz LF component can be used to form an RF plasma. Using the LF component in addition to the HF component provides a higher sputtering rate compared to examples where the LF RF energy is omitted. In some examples, the HF component may include 50 W to 6000 W of RF power. Alternatively or additionally, in some examples, the LF component may include 0 to 3000 W of RF power. Increasing the power of the HF component can help increase the concentration of inert gas ions in the plasma, thereby increasing the sputtering rate. Increasing the power of the LF component can increase the kinetic energy of the inert gas ions in the plasma, thereby helping to increase the sputtering rate.

[0087] Continuing, in some examples, at 214, method 200 modifies the composition of the silicon oxide film. In some such examples, the modification step modifies the silicon oxide film by exposing it at 216 to a plasma comprising nitrogen. This nitrides the silicon oxide film to form a silicon oxynitride film. In some examples, the modification step modifies the deposited silicon oxide film by exposing the silicon-containing film to a plasma comprising one or more of nitrous oxide, ammonia, oxygen, or molecular nitrogen.

[0088] Nitriding the silicon-containing film at 214 involves bombarding the film with nitrogen ions using plasma. Therefore, at 216, method 200 includes exposing the silicon oxide film to a plasma comprising a nitrogen source, such as molecular nitrogen, ammonia, hydrazine, a material containing a -CN group (e.g., hydrogen cyanide), or a combination thereof. Nitrogen ions in the plasma bombard the silicon-containing film to implant nitrogen into the film. Exemplary plasma frequencies include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the plasma is formed using the HF and LF components of radio frequency energy. Furthermore, in some examples, the HF component may include 50 W to 6000 W of radio frequency power. Alternatively or additionally, the LF component may include 0 to 3000 W of radio frequency power.

[0089] In some examples, the processing conditions of the modification steps can be adjusted to control the concentration of chemicals (e.g., nitrogen) in the silicon oxynitride film. For example, increasing the power of the HF component can help increase the concentration of nitrogen ions or other ions in the plasma and increase the nitridation rate. Furthermore, increasing the power of the LF component can increase the kinetic energy of nitrogen ions or other ions in the plasma, which helps to break Si-O bonds in the silicon oxynitride film. This helps to improve the nitridation rate. In some more specific examples, a 27 MHz or 13.56 MHz HF component and a 400 kHz LF component are used to form the radio frequency plasma. Using the LF component in addition to the HF component provides a higher nitridation rate compared to examples that omit the LF radio frequency energy. Furthermore, using a modification step with a longer duration helps to improve nitridation.

[0090] As mentioned above, relatively low-density silicon oxide films are more susceptible to nitriding than relatively high-density silicon oxide films. Therefore, in some examples, the processing conditions in CVD step 204 can be controlled to produce a silicon oxide film with a relatively low density, rather than one produced under other conditions. For example, using relatively low power radio frequency energy (≤1500W) can form a silicon oxide film with a lower density than that formed using relatively high power radio frequency energy (>1500W). This helps to increase the nitrogen concentration in the silicon oxynitride film formed in step 214 relative to a higher-density film under similar conditions. Therefore, the processing conditions of the modification step can be controlled to achieve the desired nitrogen concentration. In some examples, the nitrogen concentration in the silicon oxynitride film can reach 30% atomically. In other examples, any other suitable nitrogen concentration can be used to form the silicon oxynitride film.

[0091] Chemical modification of relatively thick silicon oxide films can be more difficult than nitriding relatively thin silicon oxide films. For example, implanting nitrogen or other ions into a silicon-containing film to a depth of more than a few nanometers may be challenging. Therefore, depositing a relatively thin silicon oxide layer in CVD step 204 helps to provide a more consistent nitrogen (or other substance) concentration in the modified oxide film after step 214. Thus, in some examples, step 214 includes modifying the composition of a silicon oxide film having a thickness of about 3 nm (e.g., 1 nm to 5 nm).

[0092] Continuing, at 220, method 200 includes deciding whether to perform an additional CVD cycle 202. If an additional CVD cycle is to be performed, method 200 returns to 202 and performs another CVD cycle. Any appropriate number of CVD cycles 202 can be performed during substrate processing. On the other hand, if it is decided at 220 not to perform an additional CVD cycle, method 200 terminates at 224.

[0093] In some examples, according to this disclosure, processing conditions can be varied between CVD cycles of film deposition processing. For example, the sputtering amount for removing recessed structures can vary as gaps are filled. Therefore, in some examples, the duration of a modification step in a later CVD cycle can differ from the duration of a modification step in an earlier CVD cycle. In other examples, processing conditions can be kept consistent between CVD cycles.

[0094] Figure 3 shows a flowchart illustrating an exemplary method 300 for depositing a film on a substrate using a cyclic CVD process that includes compositional modification (nitridation in this example).

[0095] CVD step 304 includes exposing the substrate to the silicon-containing precursor under conditions configured to convert the silicon-containing precursor into a silicon oxide film. In other examples, different silicon-containing films may be used. Any suitable silicon-containing precursor may be used. In some examples, at 306, method 300 includes introducing TEOS into a plasma. As mentioned above, TEOS is relatively inexpensive and can be used to form high-quality silicon oxide films using PECVD. In some examples, TEOS is deposited together with an oxidant (e.g., nitrous oxide or molecular oxygen). Furthermore, the silicon oxide film layer deposited using the TEOS precursor can be modified by nitriding, as described below. In other examples, silane-based precursors may be used to deposit the silicon-containing film. In some such examples, the silicon-containing film may comprise silicon oxide, silicon oxynitride, or silicon nitride. Further examples of silicon-containing precursors include those listed above.

[0096] In some examples, thermal CVD can be used as CVD step 304. In other examples, PECVD can be used. Examples of plasma conditions are as described above. In some examples, using relatively low-power radio frequency energy can facilitate the deposition of relatively low-density silicon-containing films. Relatively low-density silicon-containing films are more easily nitrided than relatively high-density silicon-containing films.

[0097] After executing CVD step 304, method 300 includes determining at 308 whether to execute a modification step. If a modification step is to be executed, method 300 proceeds to 310 to execute the modification step. Otherwise, for the selected CVD cycle, modification step 310 can be omitted.

[0098] Modification step 310 includes modifying the composition of the membrane by nitriding the membrane. In some examples, modification step 310 includes nitriding a silicon oxide membrane, such as a membrane formed from TEOS or a silane precursor. In other examples, a silicon nitride or silicon oxide membrane formed from a silane precursor may be further nitrided. In many more examples, any other suitable silicon-containing membrane may be nitrided.

[0099] Modified step 310 includes forming a plasma comprising a nitrogen source, such as molecular nitrogen, ammonia, hydrazine, a CN-containing substance (e.g., hydrogen cyanide), or a combination of two or more thereof. Nitrogen ions in the plasma bombard the silicon-containing membrane to implant nitrogen into the membrane. Example frequencies of the plasma include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the plasma is formed using the HF and LF components of radio frequency energy. Furthermore, in some examples, the HF component may include 50 W to 6000 W of radio frequency power, and alternatively or additionally, the LF component may include 0 to 3000 W of radio frequency power.

[0100] In some examples, the processing conditions of the modification steps can be adjusted to control the nitrogen concentration in the silicon oxynitride film. For example, increasing the power of the HF component can help increase the concentration of nitrogen ions in the plasma and improve the nitridation rate. Furthermore, increasing the power of the LF component can increase the kinetic energy of nitrogen ions in the plasma, which helps to break the Si-O bonds in the silicon oxynitride film. This helps to improve the nitridation rate. In some more specific examples, a 27 MHz or 13.56 MHz HF component and a 400 kHz LF component are used to form the plasma. Using the LF component in addition to the HF component provides a higher nitridation rate compared to examples that omit the LF RF energy. Furthermore, using a modification step with a longer duration can help improve the nitriding effect.

[0101] As described above, relatively low-density silicon oxide films are more susceptible to nitriding than relatively high-density silicon oxide films. Therefore, in some examples, the processing conditions in CVD step 304 can be controlled to produce silicon oxide films with a relatively low density compared to those produced under other conditions. For example, using relatively low power radio frequency energy of ≤1500W can form silicon oxide films with a lower density than those formed using relatively high power radio frequency energy of >1500W. This helps to increase the nitrogen concentration in the silicon oxynitride film formed in step 310 relative to a higher-density film under similar conditions. Therefore, the processing conditions of the modification step can be controlled to achieve the desired nitrogen concentration. In some examples, the nitrogen concentration in the silicon oxynitride film can reach 30% atomically. In other examples, any other suitable nitrogen concentration can be used to form the silicon oxynitride film.

[0102] Continuing, at 320, method 300 includes deciding whether to perform an additional CVD cycle 302. If an additional CVD cycle is to be performed, method 300 returns to 302 and performs another CVD cycle. Any appropriate number of CVD cycles 302 can be performed during substrate processing. On the other hand, if it is decided at 320 not to perform an additional CVD cycle, method 300 terminates at 324.

[0103] Figure 4 shows a flowchart illustrating an exemplary method 400 for depositing a film on a substrate using a cyclic CVD process including sputtering.

[0104] CVD step 404 includes exposing a substrate to a silicon-containing precursor under conditions configured to convert a silicon-containing precursor into a silicon-containing film. Exemplary silicon-containing films include silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbide, silicon carbonitride, and silicon carbonitride. Any suitable silicon-containing precursor can be used. In some examples, at 406, CVD step 404 includes depositing a silicon-containing film using a silyl precursor. In some such examples, the silicon-containing film includes silicon oxide, silicon oxynitride, or silicon nitride. Examples of silyl precursors include partially substituted and substituted variants of silanes and polysilanes. For example, silanes, ammonia, and nitrous oxide can be used as precursors for depositing silicon oxynitride films. Further examples of silicon-containing precursors for forming silicon-containing films include those listed above.

[0105] In some examples, thermal CVD can be used as CVD step 404. In other examples, PECVD can be used. For example, the silane precursor introduced at 406 can be introduced into the plasma. Examples of plasma conditions are as described above. In some examples, using relatively low-power radio frequency energy can facilitate the deposition of relatively low-density silicon-containing films. Relatively low-density silicon-containing films are more susceptible to sputtering effects than relatively high-density silicon-containing films.

[0106] After executing CVD step 404, method 400 includes determining at 408 whether to execute a modification step. If a modification step is to be executed, method 400 proceeds to 410 to execute the modification step. Otherwise, for the selected CVD cycle, modification step 410 can be omitted.

[0107] Modified step 410 includes using an inert gas to form a plasma to sputter at least a portion of the silicon-containing film. This reduces the concave structure of the silicon-containing film. Any suitable inert gas can be used. Examples include Ar, He, Ne, Kr, and Xe. Any suitable sputtering conditions can be used. Examples of suitable pressures include pressures from 0.5 Torr to 5 Torr. Examples of suitable temperatures include temperatures from 250ºC to 650ºC. In some examples, the silicon-containing precursor flows into the processing chamber via a nozzle to react with the substrate on a substrate support. In some such examples, the substrate support is heated to a first temperature, and the nozzle can be heated to a second temperature lower than the first temperature.

[0108] Any suitable plasma conditions can be used to sputter the film. Exemplary frequencies for radio frequency plasmas include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the plasma is formed using both the HF and LF components of radio frequency energy. In a more specific example, a 27 MHz HF component and a 400 kHz LF component can be used to form the radio frequency plasma. Using the LF component in addition to the HF component provides a higher sputtering rate compared to examples where the LF radio frequency energy is omitted. In some examples, the HF component may include 50 W to 6000 W of radio frequency power. Alternatively or additionally, in some examples, the LF component may include 0 to 4000 W of radio frequency power. Increasing the power of the HF component can help increase the concentration of inert gas ions in the plasma to improve the sputtering rate. Increasing the power of the LF component can increase the kinetic energy of the inert gas ions in the plasma to help improve the sputtering rate. In some examples, at 412, the modification step 410 includes modifying the silicon-containing film deposited in CVD step 404. In this way, method 400 can be used to deposit and etch silicon oxynitride films.

[0109] Continuing, at 420, method 400 includes determining whether to perform an additional CVD cycle 402. If an additional CVD cycle is to be performed, method 400 returns to 402 and performs another CVD cycle. Any appropriate number of CVD cycles 402 can be performed during substrate processing. On the other hand, if it is decided at 420 not to perform an additional CVD cycle, method 400 terminates at 424.

[0110] Figures 5A-5G schematically illustrate exemplary structures formed during a cyclic CVD process, which includes cycles of deposition and modification steps to avoid void formation. Figures 5A-5G illustrate examples of method 200 or method 400 including step 212. Referring first to Figure 5A, substrate 500 includes gap 502. Substrate 500 may comprise any suitable material. Gap 502 comprises an aspect ratio of approximately 1:1. In other examples, the gap may comprise any other suitable aspect ratio. In some examples, the gap comprises an aspect ratio up to 5:1. In some such examples, the gap comprises an aspect ratio of 0.5:1 or greater.

[0111] Figure 5B shows a substrate 500 after a CVD step, such as CVD step 204 or CVD step 404. During the CVD step, the substrate 500 is exposed to a silicon-containing precursor under conditions configured to convert the silicon-containing precursor into a silicon-containing film 504. Examples of silicon-containing films include silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbide, silicon carbonitride, and silicon carbonitride. For example, a silicon carbide film can be deposited using silane, carbon tetrafluoride, and nitrous oxide. As another example, a silicon oxynitride film can be deposited using silane, ammonia, and nitrous oxide as precursors. In some examples, plasma is used to form the silicon-containing film (i.e., PECVD).

[0112] Due to the adhesion coefficient of the silicon-containing precursor in a plasma environment, a top-heavy deposition occurs. Therefore, the silicon-containing film 504 grows faster on the upper sidewall surface 506 of the gap 502 than it grows deeper within the gap. This forms a recessed structure 508. The recessed structure 508 narrows the opening of the gap 502. This makes it more difficult for the silicon-containing precursor to form a film at the bottom of the gap 502. Therefore, a modification step is performed. Figure 5C shows the substrate 500 after the modification step, for example, step 212 or step 410, has been performed to etch the contour of the silicon-containing film 504 by sputtering. The modification step includes forming a plasma comprising gas ions. In the example shown, argon ions 510 are used to sputter the silicon-containing film 504. In other examples, other suitable inert gases can be used. Furthermore, in some examples, a nitrogen-containing gas can be used to etch and nitride the film, as detailed below. The result of the modification step is the removal of the recessed structure 508, and the contour of the silicon-containing film 504 is etched into a V-shape.

[0113] Additional deposition cycles can be performed to continue filling the gaps 502 of the substrate 500. Figure 5D shows an additional layer of silicon-containing film 504 deposited on the substrate 500 after the CVD step of a subsequent deposition cycle. Similarly, the film grows faster on the upper sidewalls 506 of the gaps 502. This forms a recessed structure 508. Continuing to refer to Figure 5E, a modification step in the subsequent deposition cycle modifies the profile of the silicon-containing film 504 by sputtering argon ions 510. This removes the recessed structure 508 in Figure 5D and modifies the profile of the silicon-containing film 504 to a V-shape.

[0114] Figure 5F shows the substrate 500 after another deposition cycle, with an additional layer of silicon-containing film 504 deposited and modified on the substrate. The silicon-containing film 504 includes a V-shaped profile that allows the gap to be filled before it closes. This helps to avoid the formation of voids. Figure 5G shows the substrate 500 after an additional deposition cycle. The silicon-containing film 504 is deposited into the void-free gap 502. Therefore, a deposition cycle including both CVD and modification steps can be used for void-free gap filling.

[0115] Figures 6A-6E schematically illustrate exemplary structures formed during a CVD process that includes modification steps to alter the composition of the film. Figures 6A-6E illustrate examples of method 200 or method 300 including step 214. Referring first to Figure 6A, substrate 600 comprises any suitable material to which a silicon oxide film can be deposited. Figure 6B shows substrate 600 after a CVD step, such as step 206 or step 306, in which TEOS 602 is introduced into the plasma. The CVD step may also include introducing an oxidant, such as nitrous oxide or molecular oxygen, into the plasma. This forms a silicon oxide film 604. In some examples, PECVD deposition of silicon oxide film 604 uses RF power from 200W to 3000W. As mentioned above, using relatively low RF power (e.g., less than or equal to 3000W) can facilitate the deposition of a relatively low-density silicon oxide film compared to using relatively high RF power. A relatively low-density silicon oxide film may be more susceptible to nitriding than a relatively high-density silicon oxide film.

[0116] Next, modification steps are performed, such as steps 214, 216, or 310. Figure 6C shows the substrate 600 after the modification steps. The modification steps include forming a plasma comprising a nitrogen source 606. In the depicted example, the nitrogen source comprises molecular nitrogen and ammonia. In other examples, either nitrogen or ammonia may be omitted. In further examples, any other suitable nitrogen source, such as hydrazine or a CN-containing substance (e.g., hydrogen cyanide), may be used alternatively or additionally. The plasma is used to bombard the layer of silicon oxide 604 with nitrogen ions, causing the layer of silicon oxide film 604 to nitrid. This forms a first layer of oxide nitride 610A.

[0117] The first layer of oxide nitride 610A can be formed using any suitable plasma conditions. Examples include RF power ranging from 50 to 6000 W and frequencies of 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the plasma is formed using both the HF and LF components of the RF energy. Examples of HF RF energy include RF power ranging from 50 W to 6000 W. Examples of LF RF energy include RF power ranging from 0 to 3000 W.

[0118] The first oxide nitride layer 610A comprises silicon oxynitride. As described above, the nitrogen concentration can be varied in the silicon oxynitride. In some examples, the nitrogen concentration in the silicon oxynitride film can reach 30% atomically. Furthermore, the processing conditions of the modification step can be adjusted to control the nitrogen concentration in the first oxide nitride layer 610A. For example, using higher power radio frequency energy helps to increase the concentration of nitrogen ions in the plasma and increase the nitridation of the silicon oxide film. Additionally, using a modification step with a longer duration can help to increase nitridation.

[0119] As mentioned above, relatively low-density silicon oxide films are more susceptible to nitriding than relatively high-density silicon oxide films. Therefore, in some examples, the silicon oxide film is deposited in a CVD step using RF power of 3000W or lower. This facilitates the deposition of a relatively low-density silicon oxide film 604 compared to silicon oxide films deposited at RF power greater than 3000W.

[0120] The deposition cycles shown in Figures 6B-6C can be repeated to form an additional silicon oxynitride layer. Figure 6D shows the substrate 600 after the CVD step of a subsequent deposition cycle. The CVD step involves introducing a TEOS 602 plasma to deposit a silicon oxide film 604 onto a first layer of oxide nitride 610A. A modification step is then performed to convert the silicon oxide into silicon oxynitride. Figure 6E shows the result of the modification step in a subsequent deposition cycle. The modification step involves forming a plasma including a nitrogen source 606. Nitrogen ions in the plasma bombard the silicon oxide film 604, causing the silicon oxide film 604 to nitride. This forms a second layer of oxide nitride 610B on top of the first layer of oxide nitride 610A. Additional deposition cycles can be performed to achieve any suitable film thickness. In this way, a silicon oxynitride film can be deposited using a TEOS precursor.

[0121] Figures 7A-7F schematically illustrate exemplary structures formed during a CVD process, which includes modification steps to simultaneously modify both the film profile and the film composition. Figures 7A-7F illustrate an example of method 200 including steps 212 and 214. Referring first to Figure 7A, substrate 700 includes gap 702. Substrate 700 may comprise any suitable material. Figure 7B shows substrate 700 after a CVD step, for example, including CVD step 204, step 206.

[0122] During the CVD step, substrate 700 is exposed to plasma and TEOS 704 is introduced into the plasma to deposit a layered silicon oxide film 706. In some examples, the silicon oxide film 706 is deposited in a PECVD step using an electrical frequency power to form the plasma. In some such examples, an RF power of 200W to 3000W is used to form the plasma. As mentioned above, using relatively low RF power ≤3000W can facilitate the deposition of a relatively low-density silicon oxide film that is more easily nitrided than using RF power greater than 3000W. In other such examples, the plasma may have an RF power greater than 1500W.

[0123] TEOS704 facilitates top-heavy deposition within the gap 702 in a plasma environment. Therefore, the silicon oxide film 706 grows faster on the upper sidewall surface 708 of the gap 702 than deeper within it. This creates a concave structure 710 and narrows the opening of the gap 702.

[0124] Therefore, a modification step is then performed to etch the silicon oxide film 706 to reduce or remove the recessed structure 710. Figure 7C shows the substrate 700 after the modification steps, including steps 212 and 214 of method 200. The modification step includes forming a plasma containing a nitrogen source 712. The plasma is used to modify the silicon oxide film 706 by nitriding and sputtering. In the example shown, the nitrogen source 712 includes nitrogen and ammonia. In other examples, any other suitable nitrogen source can be used. Examples include hydrazine and cyanide. Nitrogen ions in the plasma can be used to sputter the silicon oxide film 706. In some examples, the plasma further includes an inert gas to facilitate the sputtering of the silicon oxide film 706. Exemplary inert gases include helium, neon, argon, krypton, and xenon. Through the modification step, the silicon oxide film 706 is chemically modified to form a first layer of oxide nitride 714A. Furthermore, the recessed structure 710 is removed, and the contour of the oxide nitride 714A is modified to a V-shape.

[0125] Any suitable plasma conditions can be used to perform the modification step and form the first layer of oxide nitride 714A. Examples include RF power ranging from 50 W to 6000 W, and frequencies of 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the plasma is formed using both the HF and LF components of the RF energy. Exemplary powers of the HF RF energy include 50 W to 6000 W, and exemplary powers of the LF RF energy include 0 to 3000 W. Furthermore, the modification step can be performed at any suitable pressure (e.g., 0.5 Torr to 20 Torr). In some examples, using relatively lower pressures during the modification step provides a higher sputtering rate compared to examples using higher pressures during the modification step.

[0126] Additional deposition cycles can be performed to continue filling gap 702 using oxide nitride. Figure 7D shows substrate 700 after the CVD step in a subsequent deposition cycle. The CVD step again involves introducing TEOS 704 into the plasma to deposit an additional silicon oxide film 706 on the first layer of oxide nitride 714A. The film grows faster on the upper sidewall 708 of gap 702. This forms a recessed structure 710 in the silicon oxide film 706.

[0127] Continuing, Figure 7E shows the substrate 700 after the modification step in a subsequent deposition cycle. The modification step again involves forming a plasma including a nitrogen source 712. Nitrogen ions in the plasma bombard the silicon oxide film 706 layer to modify the film by nitriding and sputtering. As shown in Figure 7E, sputtering removes the recessed structure 710. Furthermore, the silicon oxide film 706 is nitrided to form a second layer of oxide nitride 714B.

[0128] Additional deposition cycles can be performed to deposit and modify additional layers of the silicon-containing film. Figure 7F shows substrate 700 after further CVD processing, with gaps 702 filled with oxide nitride 714. By performing a deposition cycle with modification steps including sputtering, gaps 702 are filled without voids. Furthermore, silicon oxide can be nitrided to form silicon oxynitride by modifying the silicon oxide film using plasma including a nitrogen source. In this way, gaps 702 can be filled with silicon oxynitride via CVD processing using a TEOS precursor.

[0129] Figure 8 shows a flowchart of another example method 800 for processing a substrate. Method 800 includes, at 802, performing multiple CVD cycles to deposit a silicon-containing film on the substrate. Example silicon-containing films include silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxycarbonate, silicon carbonitride, and silicon carbonitride.

[0130] In some examples, method 800 includes depositing a silicon-containing film into the feature, such as a gap. In some examples, at 804, the substrate includes a feature with an aspect ratio as high as 5:1. In other examples, the feature may have any other suitable aspect ratio.

[0131] Each CVD cycle includes, at 808, performing a CVD step by exposing the substrate to the silicon-containing precursor under conditions configured to convert the silicon-containing precursor into a silicon-containing film. Exemplary CVD processes include PECVD and thermal CVD. Performing the CVD step at 808 may include depositing any suitable silicon-containing film. In some examples, at 810, method 800 includes depositing one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbide, silicon carbonitride, or silicon carbonitride. In some examples, at 812, method 800 includes exposing the substrate to TEOS. In examples including PECVD, TEOS may be introduced into a plasma. As described above, TEOS can be used to deposit a silicon oxide film that can be nitrided in a modified step. In other examples, any other suitable silicon-containing precursor may be used. Examples include those listed above. In some examples, an oxidant is used to react with the silicon-containing precursor. Examples include molecular oxygen, nitrous oxide, water, hydrogen peroxide, and carbon dioxide. An example precursor for providing nitrogen to form a silicon oxynitride film is nitrous oxide. When using TEOS, the silicon oxynitride film can be formed on the substrate by nitriding the silicon oxynitride film using a nitrogen source to form plasma in a modified step.

[0132] In some examples, at 814, the CVD step includes depositing a silicon-containing film with a thickness of 1 nm to 10 nm. In other examples, thicknesses outside this range may be used.

[0133] In an example of CVD step 808 using PECVD, example plasma conditions include RF power ranging from 50 to 6000 W. Example frequencies of the RF plasma include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. Example frequencies of the HF component include 3 MHz to 300 MHz. Example frequencies of the LF component may include frequencies of 3 MHz and below. Any suitable RF power can be used. Examples include HF RF power of 50 to 6000 W and LF RF power of 0 to 3000 W.

[0134] As described above, using relatively low-power radio frequency (RF) energy (e.g., 50 W to 3000 W) facilitates the deposition of relatively low-density silicon oxide films, which are more easily nitrided than high-density films. Furthermore, relatively low-density silicon-containing films are easier to sputter than relatively high-density films. Therefore, in some examples, the CVD step involves forming a plasma using RF power from 50 W to 3000 W. In some more specific examples, RF power from 500 to 1000 W can be used. In other examples, RF power outside these ranges can be used. Additionally, any suitable pressure can be used to perform the CVD step at 804. Examples include pressures from 0.5 Torr to 20 Torr.

[0135] Continuing, the CVD cycle further includes performing a modification step at 820 by using plasma to bombard the silicon-containing film with ions to modify the film. Modifying the silicon-containing film includes at least modifying the contour of the silicon-containing film or modifying its composition. Therefore, in some examples, step 820 includes modifying the contour of the silicon-containing film. Additionally or alternatively, in some examples, step 820 includes modifying the composition of the silicon-containing film.

[0136] Modification step 820 can be performed in any suitable manner. In some examples, at 822, step 820 includes forming a plasma using an inert gas to alter the profile of the concave structure of the silicon-containing film by sputtering. Any suitable inert gas can be used. Examples include Ar, He, Ne, Kr, and Xe. Any suitable sputtering conditions can be used. Examples of suitable pressures include pressures from 0.5 Torr to 20 Torr. Examples of suitable temperatures include 250ºC to 650ºC. Exemplary frequencies of the radio frequency plasma include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, radio frequency energy is provided at several different frequencies and / or powers. For example, as described above, the plasma may contain an LF component and an HF component. Examples of HF component frequencies may include frequencies from 3 MHz to 300 MHz. In some examples, the HF component may include power from 50 to 6000 W. Examples of LF component frequencies may include frequencies from 3 MHz to lower. In some examples, the LF component may include power from 0 to 3000 W. Compared to examples that omit LF RF energy, using the LF component in addition to the HF component provides a higher sputtering rate. Furthermore, using the HF component (e.g., 27 MHz or 13 MHz) can help provide a higher concentration of inert gas ions and a higher sputtering rate compared to using the LF component (e.g., 400 kHz). Increasing the power of the HF component helps increase the concentration of inert gas ions in the plasma, thereby improving the sputtering rate. Additionally, increasing the power of the LF component increases the kinetic energy of the inert gas ions in the plasma, which also helps improve the sputtering rate.

[0137] In some examples, at 824, the silicon-containing film deposited in the CVD step at 804 is a silicon oxide film. In such examples, the modified step 820 may alternatively or additionally include nitriding the silicon oxide film. In some such examples, at 826, the modified step includes forming a plasma using one or more of molecular nitrogen or ammonia. In other examples, different nitrogen sources, such as hydrazine or CN-containing substances (e.g., hydrogen cyanide), may be used alternatively or additionally. Nitrogen ions in the plasma bombard the silicon-containing film to implant nitrogen into the silicon oxide film. Any suitable plasma conditions can be used. Example plasma frequencies include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the plasma is formed using an HF radio frequency energy component and an LF radio frequency energy component. Any suitable radio frequency power can be used. In some examples, the HF component may include 50 W to 6000 W of radio frequency power. Furthermore, in some examples, the LF component may include 0 to 3000 W of radio frequency power. In other examples, silicon nitride or silicon oxynitride films formed from silane precursors can be further nitrided. In many more examples, any other suitable silicon-containing film can be nitrided.

[0138] In some examples, the processing conditions of the modification step can be adjusted to control the nitrogen concentration in the silicon oxynitride film. For example, increasing the power of the HF component can help increase the concentration of nitrogen ions in the plasma and improve the nitridation rate. Furthermore, increasing the power of the LF component can increase the kinetic energy of nitrogen ions in the plasma, which helps to break the Si-O bonds in the silicon oxide film. This helps to improve the nitridation rate. In a more specific example, a 13.56 MHz HF component and a 400 kHz LF component are used to form the plasma. Using the LF component in addition to the HF component provides a higher nitridation rate compared to examples that omit the LF RF energy. Furthermore, using a modification step with a longer duration can help improve the nitridation rate. In some examples, at 828, the modification step includes nitriding and sputtering of the silicon oxide film. Examples of CVD processes that include nitriding and sputtering in the modification step have been illustrated above with reference to Figures 7A-5E. This facilitates the deposition of a silicon oxynitride film in a void-free gap-filling process using TEOS as a precursor.

[0139] Method 800 may include performing any appropriate number of CVD cycles at 802. In some examples, at 830, method 800 may optionally include performing CVD cycles with the modification step omitted.

[0140] Figure 9 schematically shows an exemplary processing tool 900 that can implement the examples described above with reference to Figures 2-6. The processing tool 900 includes a processing chamber 902 and a substrate support 904 within the processing chamber. The substrate support 904 is configured to support a substrate 906 disposed within the processing chamber 902. The substrate support 904 includes a substrate heater 908. In other examples, the heater may be omitted, or may be located at another location within the processing chamber 902.

[0141] The processing tool 900 further includes a nozzle 910. In other examples, the processing tool may include a nozzle or other means for introducing gas into the processing chamber 902, rather than a nozzle or as a supplement to a nozzle. In some examples, the processing tool 900 includes a heater configured to heat the nozzle 910. The processing tool 900 further includes flow control hardware 912. The flow control hardware 912 connects a processing gas source to the processing chamber. In the depicted example, the flow control hardware 912 connects a silicon-containing film precursor source 916, an optional nitrogen source 918, an optional oxidant source 920, and an inert gas source 924 to the processing chamber. The flow control hardware 912 may include any suitable components. Examples include mass flow controllers, valves, and conduits. For example, the flow control hardware 912 may include one or more controllable valves to fluidly connect one or more selected gas sources to the nozzle 910. The flow control hardware 912 may also include one or more mass flow controllers or other controllers for controlling the mass flow rate of the gas.

[0142] Silicon-containing membrane precursor source 916 includes any precursor compound suitable for forming a silicon-containing membrane. Example silicon-containing membranes include membranes comprising silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbide, silicon carbonitride, and silicon carbonitride. In some examples, the silicon-containing precursor source includes TEOS 916A. As mentioned above, using TEOS helps deposit high-quality membranes at a relatively low cost. Further examples of silicon-containing membrane precursors include those listed above. In some examples, two or more membrane precursor sources may be used to provide two or more corresponding membrane precursors. An exemplary precursor for providing nitrogen to form a silicon nitride or silicon oxynitride membrane is nitrous oxide. Alternatively, a carbon-containing precursor source (not shown) may be used to provide a carbon-containing precursor to form a silicon-containing membrane comprising carbon. Examples of such silicon-containing membranes include silicon carbide, silicon carbide, silicon carbonitride, and silicon carbonitride. Examples of carbon-containing precursors for forming such membranes include alkanes, alkenes, alkynes, cyclic hydrocarbons, aromatics, alkyl halides, alkylamines, and alkyl diamines.

[0143] Optional nitrogen source 918 includes any suitable nitrogen source that can be introduced into the plasma for nitriding of the membrane. In some examples, the nitrogen source includes molecular nitrogen 918A. In some examples, the nitrogen source includes ammonia 918B. Further examples of nitrogen sources include hydrazine and cyanide. In some examples, nitrogen source 918 includes two or more nitrogen-containing compounds. In examples involving modifying the membrane profile by sputtering without nitriding, nitrogen source 918 may be omitted.

[0144] Optional oxidant source 920 includes any oxidant suitable for forming silicon oxide, silicon oxynitride, silicon carbon oxynitride, or silicon carbonitride films. Examples of oxidants may include molecular oxygen, nitrous oxide, water, hydrogen peroxide, and carbon dioxide.

[0145] The inert gas source 924 may include any suitable inert gas. Examples include argon, helium, neon, krypton, and xenon. In some examples, using a heavier inert gas (such as Ar, Kr, or Xe) helps to increase the sputtering rate of the silicon-containing film compared to using a lighter inert gas (such as He or Ne).

[0146] The processing tool 900 further includes a venting system 932. The venting system 932 is configured to vent gases from the processing chamber 902. The venting system 932 may include any suitable hardware, including one or more low-vacuum pumps, one or more high-vacuum pumps, and one or more valves for controlling the venting flow rate. The flow control hardware 912 and the venting system 932 may operate together to achieve a selected pressure in the processing chamber 902 during substrate processing. Exemplary pressures include pressures from 0.5 Torr to 20 Torr. Furthermore, the venting system 932 may be operated to purge the processing chamber 902.

[0147] The processing tool 900 further includes a radio frequency power supply 934 electrically connected to the nozzle 910. The radio frequency power supply 934 is configured to form plasma using a gas mixture.

[0148] For example, during a CVD step, an RF power supply 934 can be operated to form a plasma using a gas mixture comprising one or more film precursors to deposit a silicon-containing film. Additionally, during a modification step, the RF power supply 934 can be operated to form a plasma using an inert gas to modify the profile of the silicon-containing film by sputtering. Alternatively or additionally, during a modification step, the RF power supply 934 can be operated to form a plasma including a nitrogen source to modify the composition of the silicon-containing film by nitriding. In the depicted example, a capacitively coupled plasma can be formed between a nozzle 910 and a substrate support 904 in a processing chamber 902. In various examples, the RF power supply can be supplied to either the nozzle electrode or the substrate support electrode. As shown in FIG9, RF energy is supplied to the nozzle 910, and the substrate support 904 is configured as a grounded opposite electrode. In other examples, the RF power supply 934 can provide RF energy to the substrate support 904, and the nozzle 910 can be grounded. In such examples, supplying RF power to the substrate support 904 can increase the sputtering rate of the silicon-containing film. In some examples, the radio frequency power supply 934 is operable to pulse the plasma using any suitable duty cycle. In other examples, the radio frequency power supply 934 is operable to form a continuous wave plasma, rather than a pulsed plasma. In some examples, a remote plasma chamber can be used to form a remote plasma. During the modification step, the remote plasma can be introduced into the processing chamber.

[0149] The processing tool 900 further includes a matching network 936 comprising impedance matching for an RF power supply 934. The RF power supply 934 can be configured to provide RF energy of any suitable frequency and power. Exemplary frequencies include 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz. In some examples, the RF power supply 934 is configured to operate at multiple different frequencies and / or powers. For example, as described above, the plasma may include an LF RF energy component and an HF RF energy component. Examples of frequencies for the LF RF energy component may include 3 MHz and lower. In some examples, the LF RF energy component may include power from 0 to 3000 W. Furthermore, the HF RF energy component may include frequencies from 3 MHz to 300 MHz. In some examples, the HF RF energy component may include power from 50 W to 6000 W.

[0150] The processing tool 900 further includes a controller 950 configured to control the operation of the processing tool. The controller 950 is operatively coupled to a substrate heater 908, flow control hardware 912, an exhaust system 932, and an RF power supply 934. The controller 950 is configured to control various functions of the processing tool 900 to perform deposition cycles including CVD steps and modification steps. For example, the controller 950 is configured to control the processing tool 900 to operate the substrate heater 908 to heat the substrate to a desired temperature. Examples include temperatures from 250ºC to 1200ºC. The controller 950 is also configured to operate the flow control hardware 912 to allow selected gases or gas mixtures to flow into the processing chamber 902 at a selected rate. The controller 950 is further configured to operate the exhaust system 932 to remove gases from the processing chamber 902. For example, the controller 950 may control the exhaust system 932 and / or the flow control hardware 912 to purge the processing chamber 902. The controller 950 is configured to operate the radio frequency power supply 934 to form plasma, and to control any other appropriate functions of the processing tool 900.

[0151] Controller 950 is operable to process tool 900 to perform multiple deposition cycles to process substrate 906. Controller 950 is operable to process tool 900 to perform CVD steps and modification steps. For example, in the CVD step, controller 950 is configured to operate flow control hardware 912 to introduce a silicon-containing precursor from silicon-containing precursor source 916 into processing chamber 902. This is performed under conditions configured to convert the silicon-containing precursor into a silicon-containing film on substrate 906. For example, during the CVD step, controller 950 is operable to operate substrate heater 908 to heat the substrate to a desired temperature to promote the formation of the silicon-containing film. Additionally or alternatively, during the CVD step, controller 950 is operable to operate RF power supply 934 to form a plasma to promote the formation of the silicon-containing film. During the modification step, controller 950 is operable to operate flow control hardware 912 and RF power supply 934 to form a plasma to bombard the silicon-containing film with ions. This can modify the profile of the silicon-containing film by sputtering or modify the composition of the silicon-containing film by nitriding. The controller 950 may include any suitable computing system. An example computing system is described below with reference to FIG10.

[0152] Therefore, gaps in the substrate can be filled without creating voids by performing a CVD cycle that includes modifying the film profile via sputtering. This provides gap filling with relatively high aspect ratios (e.g., 0.5:1 or greater) using CVD, compared to examples that omit the modification step. Furthermore, silicon oxynitride films can be deposited in a cyclic CVD process using TEOS by performing a CVD cycle that includes modifying the film composition via nitriding. This reduces costs compared to examples using more expensive aminosilane precursors. Additionally, the modification step can include both sputtering and nitriding to deposit a silicon oxynitride film into the gaps using a cyclic CVD process.

[0153] Figure 10 schematically shows a non-limiting example of a computing system 1000 that can perform one or more of the methods and processes described above. The computing system 1000 is shown in a simplified form. The computing system 1000 may take the form of one or more personal computers, workstations, computers integrated with wafer processing tools, and / or network-accessible server computers.

[0154] The computing system 1000 includes a logic subsystem 1002 and a storage subsystem 1004. The computing system 1000 may optionally include a display subsystem 1006, an input subsystem 1008, a communication subsystem 1010, and / or other components not shown in Figure 10. The controller 950 is an example of the computing system 1000.

[0155] The logic subsystem 1002 includes one or more physical devices configured to execute instructions. For example, a logic machine may be configured to execute instructions that are part of one or more application programs, services, programs, routines, libraries, objects, components, data structures, or other logical constructs. Such instructions may be implemented to perform tasks, implement data types, transition the state of one or more components, achieve technical effects, or otherwise achieve desired results.

[0156] A logic machine may include one or more processors configured to execute software instructions. Additionally or alternatively, a logic machine may include one or more hardware or firmware logic machines configured to execute hardware or firmware instructions. The processor of the logic machine may be single-core or multi-core, and the instructions executed on it may be configured for sequential, parallel, and / or distributed processing. The various components of the logic machine may optionally be distributed across two or more separate devices that can be remotely located and / or configured for coordinated processing. The various aspects of the logic machine can be virtualized and executed via remotely accessible networked computing devices configured in a cloud computing configuration.

[0157] Storage subsystem 1004 includes one or more physical devices configured to store instruction 1012, which is executable by a logic machine to implement the methods and processes described herein. When such methods and processes are implemented, the state of storage subsystem 1004 can be transformed—for example, to store different data.

[0158] Storage subsystem 1004 may include removable and / or built-in devices. Storage subsystem 1004 may include optical storage (e.g., CD, DVD, HD-DVD, Blu-ray disc, etc.), semiconductor storage (e.g., RAM, EPROM, EEPROM, etc.), and / or magnetic storage (e.g., hard disk drive, floppy disk drive, magnetic tape drive, MRAM, etc.). Storage subsystem 1004 may include volatile, non-volatile, dynamic, static, read / write, read-only, random access, sequential access, location-addressable, file-addressable, and / or content-addressable devices.

[0159] It should be understood that the storage subsystem 1004 includes one or more physical devices. However, alternatively, aspects of the instructions described herein may be propagated via a communication medium (e.g., electromagnetic signals, optical signals, etc.) that is not held by a physical device for a limited duration.

[0160] Aspects of the logic subsystem 1002 and the storage subsystem 1004 can be integrated together into one or more hardware logic components. For example, such hardware logic components may include field-programmable gate arrays (FPGAs), program-specific and application-specific integrated circuits (PASICs / ASICs), program-specific and application-specific standard products (PSSPs / ASSPs), systems-on-a-chip (SOCs), and complex programmable logic devices (CPLDs).

[0161] When included, the display subsystem 1006 can be used to present a visual representation of the data stored by the storage subsystem 1004. This visual representation may take the form of a graphical user interface (GUI). Since the methods and processes described herein alter the data held by the storage device and thus change the state of the storage device, the state of the display subsystem 1006 can also be transformed to visually represent the changes in the underlying data. The display subsystem 1006 may include one or more display devices using virtually any type of technology. Such display devices may be combined with the logical subsystem 1002 and / or the storage subsystem 1004 in a shared enclosure, or such display devices may be peripheral display devices.

[0162] When included, the input subsystem 1008 may include or interact with one or more user input devices (e.g., a keyboard, mouse, or touchscreen). In some examples, the input subsystem may include or interact with selected Natural User Input (NUI) components. Such components may be integrated or peripheral, and the translation and / or processing of input actions may be performed on-board or off-board. Exemplary NUI components may include microphones for speech and / or voice recognition, and infrared, color, stereo, and / or depth cameras for machine vision and / or gesture recognition.

[0163] When included, the communication subsystem 1010 can be configured to communicatively couple the computing system 1000 to one or more other computing devices. The communication subsystem 1010 may include wired and / or wireless communication devices compatible with one or more different communication protocols. As a non-limiting example, the communication subsystem may be configured to communicate using a wireless telephone network, or a wired or wireless local area network or wide area network. In some examples, the communication subsystem may allow the computing system 1000 to send messages to and / or receive messages from other devices using a network such as the Internet.

[0164] It should be understood that the configurations and / or methods described herein are exemplary in nature, and these particular examples (one or more) should not be considered limiting, as many variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Therefore, the various actions shown and / or described may be performed in the order shown and / or described, in another order, in parallel, or omitted. Similarly, the order of the above processes may be changed.

[0165] The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of various processes, systems and configurations, as well as other features, functions, behaviors and / or characteristics disclosed herein, and any and all equivalent schemes thereof.

Claims

1. A method for performing chemical vapor deposition (CVD), the method comprising: Performing multiple CVD cycles to form a silicon-containing film on a substrate, each of the multiple CVD cycles comprising: The CVD step is performed by exposing the substrate to a gas flow of the silicon-containing precursor, under conditions configured to convert a silicon-containing precursor into the silicon-containing film on the substrate, and... The modification steps are performed by using plasma to bombard the silicon-containing film with ions to at least modify the contour of the silicon-containing film or modify the composition of the silicon-containing film.

2. The method according to claim 1, wherein the modification step includes: The plasma is formed using an inert gas to alter the contour of the concave structure of the silicon-containing film via sputtering.

3. The method according to claim 2, wherein the silicon-containing precursor comprises a silane precursor, and the silicon-containing film comprises silicon oxide, silicon oxynitride, or silicon nitride.

4. The method of claim 1, wherein the plasma in the modified step is formed using radio frequency energy comprising a low-frequency energy component of 3 MHz or lower and a high-frequency energy component of 3 MHz to 300 MHz.

5. The method of claim 1, wherein the plasma in the CVD step is formed using radio frequency energy comprising a high-frequency component of 3 MHz to 300 MHz and omitting the low-frequency component.

6. The method of claim 1, wherein the silicon-containing film deposited in the CVD step is a silicon oxide film, wherein the silicon-containing precursor comprises tetraethoxysilane, and wherein the modification step comprises nitriding the silicon oxide film.

7. The method of claim 6, wherein nitriding the silicon oxide film comprises forming the plasma using one or more of ammonia, molecular nitrogen, hydrazine, or a CN-containing substance.

8. The method of claim 6, wherein the modification step includes sputtering and modifying the composition of the silicon-containing film.

9. The method of claim 1, wherein modifying the composition of the silicon-containing film comprises nitriding the silicon-containing film.

10. The method of claim 1, wherein the CVD step comprises forming a silicon oxide film, a silicon oxynitride film, or a silicon nitride film using a silane precursor, and wherein modifying the composition of the silicon-containing film by nitriding the silicon-containing film comprises nitriding the silicon oxide film, the silicon oxynitride film, or the silicon nitride film.

11. The method of claim 1, further comprising performing a CVD cycle that omits the modification step.

12. A method for performing plasma-enhanced chemical vapor deposition (CVD), the method comprising: Execute multiple CVD cycles, wherein the CVD cycles in the multiple CVD cycles include: The CVD step is performed by introducing a gas stream of tetraethoxysilane (TEOS) into a plasma to deposit a silicon oxide film on a substrate, and After the CVD step is performed, a nitriding step is performed by exposing the substrate to a plasma including a nitrogen source to nitrid the silicon oxide film, thereby forming a silicon oxynitride film.

13. The method according to claim 12, wherein the nitrogen source comprises one or more of nitrogen, ammonia, hydrazine, or a CN-containing substance.

14. The method of claim 12, wherein the plasma comprising the nitrogen source is formed using radio frequency power comprising a low-frequency energy component of 3 MHz or lower and a high-frequency energy component of 3 MHz to 300 MHz.

15. The method of claim 12, wherein the silicon oxynitride film comprises up to 30% nitrogen by atomic percentage.

16. The method of claim 12, wherein exposing the substrate to the plasma further comprises sputtering a concave structure of the silicon oxide film.

17. A chemical vapor deposition (CVD) tool comprising: Processing room; A substrate support is disposed in the processing chamber; Flow control hardware configured to control the flow rate of gas flowing into the processing chamber from one or more gas sources; as well as A controller configured to execute multiple CVD cycles, each of the multiple CVD cycles including a CVD step and a modification step, the controller being configured to: In each CVD step, the flow control hardware is operated to introduce a silicon-containing precursor from a silicon-containing precursor source into the processing chamber, thereby exposing the substrate to the silicon-containing precursor under conditions configured to convert the silicon-containing precursor into a silicon-containing film on the substrate. In each modification step, the flow control hardware and radio frequency power supply are operated to form plasma so that ions bombard the surface of the silicon-containing film to at least modify the contour of the silicon-containing film or modify the composition of the silicon-containing film.

18. The CVD tool of claim 17, wherein the controller is configured to operate the flow control hardware and the radio frequency power supply to form the plasma using an inert gas, thereby altering the profile of the silicon-containing recessed portion by sputtering.

19. The CVD tool of claim 17, further comprising the silicon-containing precursor source, wherein the silicon-containing precursor source comprises tetraethoxysilane or silane, and wherein the controller is further configured to, in the modification step, operate the flow control hardware and the radio frequency power supply to modify the deposited silicon-containing film using one or more of argon, helium, nitrous oxide, ammonia, oxygen, or molecular nitrogen.

20. The CVD tool of claim 17, further comprising the silicon-containing precursor source, wherein the silicon-containing precursor source comprises silane, and wherein the controller is further configured to, in the modification step, operate the flow control hardware and the radio frequency power supply to modify the deposited silicon-containing film using one or more of argon, helium, nitrous oxide, ammonia, or molecular nitrogen.

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