Method for preparing films containing silicon and nitrogen

Abstract

A method for forming a silicon nitride film that may be doped with carbon by a plasma ALD process comprises introducing a substrate into a reactor that is heated to a maximum of about 600°C. At least one silicon precursor as defined herein and having one or two Si-C-Si bonds is introduced to form a chemically adsorbed film on the substrate. Any unconsumed precursor and / or reaction byproducts in the reactor are then purged with a suitable inert gas. A plasma containing nitrogen is introduced into the reactor to react with the chemically adsorbed film to form a silicon nitride film that may be doped with carbon. Any reaction byproducts of the reactor are purged again with a suitable inert gas. These steps are repeated as needed to achieve a predetermined thickness of the deposited silicon nitride film that may be doped with carbon.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 740,478, filed on October 3, 2018, the entire contents of which are incorporated herein by reference. Field of the Invention

[0003] The present invention relates to compositions and methods for making electronic devices. More specifically, the present invention relates to compounds, compositions and methods for depositing silicon-containing films (such as, but not limited to, stoichiometric silicon nitride, carbon-doped silicon nitride films and carbon-doped silicon oxynitride films) with low dielectric constant (<6.0) and high oxygen ashing resistance. Background of the Invention

[0005] Silicon nitride films are used in various applications in semiconductors. For example, silicon nitride films are used as final passivation and mechanical protection layers for integrated circuits, mask layers for selective oxidation of silicon, as one of the dielectric materials in the oxide-nitride-oxide (ONO) layer of a stack of DRAM capacitors or 3D NAND flash memory chips, or as a CMP stop layer in shallow trench isolation applications. In one specific application, the ONO stack in 3D NAND flash memory requires silicon nitride with low stress and a high wet etch rate in phosphoric acid.

[0006] Olsen, "Analysis of LPCVD Process Conditions for the Deposition of Low Stress Silicon Nitride", 5 Materials Science in Semiconductor Process 51 (2002) describes a wide range of process conditions for optimizing the deposition of low stress silicon nitride films by low pressure chemical vapor deposition. The results show that increasing the refractive index to more than 2.3 by increasing the gas flow does not significantly reduce the residual stress, but has a significant adverse effect on thickness uniformity and deposition rate.

[0007] Taylor et al., "Hexachlorodisilane as a Precursor in the LPCVD of Silicon Dioxide and Silicon Oxynitride Films", 136 J. Electrochem. Soc. 2382 (1989) describe the growth of silicon dioxide and silicon oxynitride films by LPCVD using a gas phase mixture of Si2Cl6, N2 and NH3. Silicon dioxide and silicon oxynitride films were grown by LPCVD using a gas phase mixture of HCDS, N2O and NH3 in the temperature range of 600-850°C. The deposited silicon dioxide and silicon oxynitride films showed low chlorine content, typically <1% atomic percent.

[0008] M. Tanaka et al., "Film Properties of Low-k Silicon Nitride Films Formed by Hexachlorodisilane and Ammonia", 147 J. Electrochem. Soc. 2284 (2000) describe a low temperature process for forming silicon nitride (SiN) with good step coverage by low pressure chemical vapor deposition (LPCVD) using hexachlorodisilane (HCD).

[0009] JP2000100812 describes a method for depositing a film using SiCl4 and NH3 as source gases. NH3 can be used to nitride the substrate surface before deposition. An extremely thin film with improved insulating properties is formed. The silicon nitride film can be used as a capacitor insulator film for semiconductor integrated circuits.

[0010] US Patent No. 6,355,582 describes a method for forming a silicon nitride film, in which a substrate on which a film is to be formed is heated, and silicon tetrachloride and ammonia gas are supplied to the substrate heated to a predetermined temperature.

[0011] U.S. Patent No. 10,049,882 describes an atomic layer deposition (ALD) method for manufacturing a semiconductor device, including the step of forming a dielectric layer on a structure with a height difference. The method includes forming a structure with a height difference on a substrate, and forming a dielectric layer structure on the structure. Forming the dielectric layer structure includes forming a first dielectric layer containing silicon nitride on the structure with a height difference. Forming the first dielectric layer includes feeding a first gas containing pentachlorodisilane (PCDS) or diisopropylamine pentachlorodisilane (DPDC) as a silicon precursor and a second gas containing a nitrogen component into a chamber containing the substrate, so that the first dielectric layer is formed in situ on the structure with a height difference.

[0012] PCT Publication No. WO2018063907 discloses a class of chlorodisilazanes, silicon-heteroatom compounds synthesized therefrom, a device comprising the silicon-heteroatom compound, a method for preparing the chlorodisilazanes, the silicon-heteroatom compounds and the device; and uses of the chlorodisilazanes, the silicon-heteroatom compounds and the device.

[0013] PCT Publication No. WO2018057677 discloses a composition for film formation, which contains trichlorodisilane as a silicon precursor. The composition contains a silicon precursor compound and at least one of an inert gas, molecular hydrogen, a carbon precursor, a nitrogen precursor, and an oxygen precursor. The disclosure also discloses a method for forming a silicon-containing film on a substrate using the silicon precursor compound and the silicon-containing film formed thereby.

[0014] U.S. Patent No. 9,984,868 discloses a cyclic method for depositing a silicon nitride film on a substrate. In one embodiment, the method includes supplying a halosilane as a silicon precursor into a reactor; supplying a purge gas to the reactor; and providing an ionized nitrogen precursor into the reactor to react with the substrate and form a silicon nitride film.

[0015] Finally, U.S. Patent Publication No. 2009 / 0155606 discloses a cyclic method for depositing a silicon nitride film on a substrate. In one embodiment, a method includes supplying chlorosilane to a reactor in which a substrate is processed; supplying a purge gas to the reactor; and providing an ammonia plasma to the reactor. The method allows the formation of a silicon nitride film at a low process temperature and at a high deposition rate. The resulting silicon nitride film has relatively few impurities and relatively high quality. In addition, a silicon nitride film having good step coverage on high aspect ratio features and a thin and uniform thickness can be formed.

[0016] There is a need in the art to provide a composition and method of using the same for depositing high carbon content (eg, about 10 atomic % or more carbon content as measured by X-ray photoelectron spectroscopy (XPS)) doped silicon-containing films for certain applications in the electronics industry.

[0017] Therefore, it is desirable to develop a method for forming high quality silicon nitride or carbon-doped silicon nitride using a chemical vapor deposition (CVD) or atomic layer deposition (ALD) process or an ALD-like process (e.g., but not limited to a cyclic chemical vapor deposition process). A particular application, such as an ONO stack in a 3D NAND flash memory, requires a silicon nitride, silicon oxynitride, or carbon oxynitride film that exhibits low stress and / or a high wet etch rate in phosphoric acid. In addition, it may be desirable to develop low temperature deposition (e.g., deposition at one or more temperatures of about 500° C. or less) in a CVD, ALD, or ALD-like process to improve one or more film properties, such as, but not limited to, purity and / or density.

[0018] The disclosures of previously identified patents, patent applications, and publications are incorporated herein by reference.

[0019] There is a need in the art to provide a composition and a method of using the composition for depositing silicon nitride or carbon-doped silicon nitride having the following characteristics: a) a carbon content of about 5 atomic % or less, about 3 atomic % or less, about 2 atomic % or less, about 1 atomic % or even less, preferably stoichiometric silicon nitride, as measured by X-ray photoelectron spectroscopy (XPS); b) an oxygen content of about 5 atomic % or less, about 3 atomic % or less, about 2 atomic % or less, about 1 atomic % or less, as measured by X-ray photoelectron spectroscopy (XPS); and a step coverage of 90% or more, 95% or more, 99% or more. SUMMARY OF THE INVENTION

[0021] In one aspect, the above needs are met by providing a method for forming a silicon nitride film that may be carbon doped by a plasma ALD process. According to the method, a substrate comprising surface features is introduced into a reactor. The reactor is heated to one or more temperatures in the range of up to about 600° C. The reactor may be maintained at a pressure of 100 Torr or less. At least one silicon precursor is introduced into the reactor, wherein the silicon precursor has one or two Si-C-Si bonds and is selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-1,3-disilapentane The invention relates to a novel nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide, a nanostructured carbonyl oxide,

[0022] The reactor is then purged of any unconsumed precursors and / or reaction byproducts with a suitable inert gas.A plasma comprising nitrogen is introduced into the reactor to react with the chemisorbed film to form a silicon nitride film which may be carbon doped.

[0023] Next, any reaction byproducts in the reactor are purged again with a suitable inert gas. The steps of introducing the precursor, purging (as needed), introducing the plasma and purging again (as needed) are repeated as needed to allow the deposited carbon-doped silicon nitride film to reach a predetermined thickness.

[0024] The above needs and other needs can be further met by a method of forming a silicon nitride, carbon-doped silicon nitride or carbon-doped silicon oxynitride film via a plasma ALD process. According to the method, a substrate comprising surface features is introduced into a reactor. The reactor is heated to one or more temperatures in the range of up to about 600° C. The reactor can be maintained at a pressure of 100 Torr or less. At least one silicon precursor is introduced into the reactor to form a chemically adsorbed film on the substrate, wherein the silicon precursor has one or two Si-C-Si bonds and is selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1 , 1,1,3,3-pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane and 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane.

[0025] Any unconsumed precursors and / or reaction byproducts in the reactor are purged with a suitable inert gas. A plasma containing an ammonia source is introduced into the reactor to react with the chemisorbed film to form a silicon nitride or carbon-doped silicon nitride film.

[0026] Next, any reaction byproducts in the reactor are purged again with a suitable inert gas. The steps of introducing precursors, purging (as needed), introducing plasma, and purging again (as needed) are repeated as needed to achieve a predetermined thickness of the silicon nitride or carbon-doped silicon nitride film.

[0027] Optionally, the resulting silicon nitride or carbon-doped silicon nitride film is subsequently exposed to an oxygen source at one or more temperatures from about ambient temperature to 1000° C., preferably from about 100° C. to 400° C., to convert the silicon nitride film to a silicon oxynitride film, or to convert the carbon-doped silicon nitride film to a carbon-doped silicon oxynitride film. DETAILED DESCRIPTION OF THE INVENTION

[0029] Throughout the specification, the term "ALD or ALD-like" refers to a process including but not limited to the following processes: a) various reactants including silicon precursors and reactive gases are sequentially introduced into a reactor, for example, a single wafer ALD reactor, a semi-batch ALD reactor, or a batch furnace ALD reactor; b) various reactants including silicon precursors and reactive gases are exposed to the substrate by moving or rotating the substrate to different sections of the reactor, and each section is separated by an inert gas curtain, i.e., a spatial ALD reactor or a roll-to-roll ALD reactor.

[0030] Throughout the specification, the term "plasma containing / including ammonia" refers to a reactive gas or gas mixture generated in situ or remotely by a plasma generator. The gas or gas mixture is selected from ammonia, a mixture of ammonia and helium, a mixture of ammonia and neon, a mixture of ammonia and argon, a mixture of ammonia and nitrogen, a mixture of ammonia and hydrogen, and combinations thereof.

[0031] Throughout the specification, the term "inert gas plasma" refers to a reactive inert gas or inert gas mixture generated in situ or remotely by a plasma generator. The inert gas or gas mixture is selected from helium, neon, argon and combinations thereof.

[0032] Throughout the specification, the term "ashing" refers to the process of removing photoresist or carbon hard mask using a plasma containing an oxygen source (e.g., O2 / inert gas plasma, O2 plasma, CO2 plasma, CO plasma, H2 / O2 plasma, or a combination thereof) during semiconductor manufacturing.

[0033] Throughout this specification, the term "damage resistance" refers to the film properties after the oxygen ashing process. Good or high damage resistance is defined as the following film properties after oxygen ashing: film dielectric constant below 6; bulk (more than The carbon content in the depth is within 5at.% before ashing; near the surface (less than Depth) and body (greater than The difference in dilute HF etching rate between films with a depth of less than The membrane is damaged.

[0034] Throughout the specification, the term "alkyl hydrocarbon" refers to a linear or branched C1-C 20 Hydrocarbon or cyclic C6-C 20 Hydrocarbons. Exemplary hydrocarbons include, but are not limited to, heptane, octane, nonane, decane, dodecane, cyclooctane, cyclononane, and cyclodecane.

[0035] Throughout the specification, the term "aromatic hydrocarbons" refers to C6-C 20 Aromatic hydrocarbons. Exemplary aromatic hydrocarbons include, but are not limited to, toluene and mesitylene.

[0036] Throughout the specification, the term "step coverage" as used herein is defined as the percentage of two thicknesses of a film deposited in a structured or feature substrate having a via or trench or both, with a bottom step coverage being the ratio (%) of the thickness at the bottom of the feature divided by the thickness at the top of the feature, and an intermediate step coverage being the thickness on the feature sidewalls divided by the thickness at the top of the feature. Films deposited using the methods described herein exhibit a step coverage of about 80% or greater or about 90% or greater, indicating that the film is conformal.

[0037] Throughout the specification, the term "plasma containing ammonia" refers to a reactive gas or gas mixture generated in situ or remotely by a plasma generator. The gas or gas mixture is selected from ammonia, a mixture of ammonia and helium, a mixture of ammonia and neon, a mixture of ammonia and argon, a mixture of ammonia and nitrogen, a mixture of ammonia and hydrogen, nitrogen, a mixture of nitrogen and helium, a mixture of nitrogen and neon, a mixture of nitrogen and argon, and combinations thereof.

[0038] Throughout the specification, the term "plasma containing / including nitrogen" refers to a reactive gas or gas mixture generated in situ or remotely by a plasma generator. The gas or gas mixture is selected from nitrogen, a mixture of nitrogen and helium, a mixture of nitrogen and neon, a mixture of nitrogen and argon, a mixture of ammonia and nitrogen, a mixture of nitrogen and hydrogen, and combinations thereof.

[0039] Described herein are silicon precursor compositions for depositing silicon nitride or carbon-doped silicon nitride having the following characteristics and methods comprising such compositions: a) a carbon content of about 5 atomic % or less, about 3 atomic % or less, about 2 atomic % or less, about 1 atomic % or even less, preferably stoichiometric silicon nitride, as measured by X-ray photoelectron spectroscopy (XPS); b) an oxygen content of about 5 atomic % or less, about 3 atomic % or less, about 2 atomic % or less, about 1 atomic % or less, as measured by X-ray photoelectron spectroscopy (XPS); and a step coverage of 90% or more, 95% or more, or 99% or more.

[0040] In one aspect, a composition for depositing a silicon-containing film comprises: (a) at least one silicon precursor compound having one or two Si-C-Si bonds selected from the group consisting of 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, and 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapropane. ,3,3-pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane, 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane; and (b) at least one solvent.

[0041] Table 1. Silicon precursors with one Si-C-Si bond

[0042]

[0043] Table 2. Silicon precursors with two Si-C-Si bonds

[0044]

[0045] In certain embodiments of the compositions described herein, exemplary solvents may include, but are not limited to, ethers, tertiary amines, alkyl hydrocarbons, aromatic hydrocarbons, tertiary amino ethers, siloxanes, and combinations thereof. In certain embodiments, the difference between the boiling point of the compound having one Si-C-Si or two Si-C-Si bonds and the boiling point of the solvent is 40°C or less. The weight percent of the silicon precursor compound in the solvent may vary from 1 to 99 weight percent, or from 10 to 90 weight percent, or from 20 to 80 weight percent, or from 30 to 70 weight percent, or from 40 to 60 weight percent, to 50 to 50 weight percent. In some embodiments, the composition may be delivered to a reactor chamber for a silicon-containing film via direct liquid injection using conventional direct liquid injection equipment and methods. In one embodiment of the method described herein, the carbon content of the silicon nitride or carbon-doped silicon nitride film is less than 5 at.% or less, and is deposited using a plasma enhanced ALD process. In this embodiment, the method comprises:

[0046] a. placing one or more substrates comprising surface features into a reactor and heating the reactor to one or more temperatures in the range of ambient temperature to about 600° C., and optionally maintaining the reactor at a pressure of 100 Torr or less;

[0047] b. Introducing into the reactor at least one silicon precursor having one or two Si-C-Si bonds, which is selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapropane, 3-Pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane, 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane;

[0048] c. purging with an inert gas to remove any unreacted silicon precursor;

[0049] d. providing a plasma containing an ammonia source into the reactor to react with the surface to form a silicon nitride or carbon-doped silicon nitride film; and

[0050] e. Purge with inert gas to remove any reaction by-products;

[0051] Steps b to e are repeated until a film of desired thickness is deposited. In certain embodiments, the method described herein further comprises:

[0052] f. Optionally, the silicon nitride or carbon-doped silicon nitride film is subjected to post-deposition treatment with thermal annealing or spike annealing at a temperature of 400 to 1000° C. or a UV light source. In this or other embodiments, the UV exposure step can be performed during film deposition or once deposition is complete.

[0053] g. Optionally providing a post-deposition exposure step of exposing the carbon-doped silicon nitride film to a plasma containing hydrogen or an inert gas or nitrogen to improve at least one physical property of the film.

[0054] In another embodiment of the method described herein, the silicon nitride or carbon-doped silicon nitride film has a carbon content of 5 at.% or less and is deposited using a plasma enhanced ALD process. In this embodiment, the method includes:

[0055] a. placing one or more substrates comprising surface features into a reactor (e.g., a conventional ALD reactor) and heating the reactor to one or more temperatures ranging from ambient temperature to about 600° C., and optionally maintaining the reactor at a pressure of 100 Torr or less;

[0056] b. Introducing into the reactor at least one silicon precursor having one or two Si-C-Si bonds, which is selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapropane, 3-Pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane, 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane;

[0057] c. Purge with inert gas;

[0058] d. providing a plasma containing / including an ammonia source into the reactor to react with the surface to form a silicon nitride or carbon-doped silicon nitride film;

[0059] e. Purge with inert gas to remove reaction by-products;

[0060] wherein steps b to e are repeated until a film of desired thickness is deposited. In certain embodiments, the method described herein further comprises:

[0061] f. Optionally, post-deposition treatment of the silicon nitride or carbon-doped silicon nitride film with a spike anneal at a temperature of 400 to 1000° C. or a UV light source. In this or other embodiments, the UV exposure step may be performed during film deposition or once deposition is complete.

[0062] g. Optionally providing a post-deposition exposure to expose the silicon nitride or carbon-doped silicon nitride film to a plasma containing hydrogen or an inert gas or nitrogen to improve at least one film physical property.

[0063] In another embodiment of the method described herein, the carbon-doped silicon oxynitride has a carbon content of 5 at.% or less and is deposited using a plasma enhanced ALD process. In this embodiment, the method comprises:

[0064] a. placing one or more substrates comprising surface features into a reactor (e.g., a conventional ALD reactor) and heating the reactor to one or more temperatures ranging from ambient temperature to about 600° C., and optionally maintaining the reactor at a pressure of 100 Torr or less;

[0065] b. Introducing into the reactor at least one silicon precursor having one or two Si-C-Si bonds, which is selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapropane, 3-Pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane, 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane;

[0066] c. Purge with inert gas;

[0067] d. providing a plasma containing / including an ammonia source into the reactor to react with the surface to form a silicon nitride film;

[0068] e. Purge with inert gas to remove reaction by-products;

[0069] wherein steps b to e are repeated until a film of desired thickness is deposited. In certain embodiments, the method described herein further comprises:

[0070] f. providing a post-deposition treatment of the silicon nitride or carbon-doped silicon nitride film with an oxygen source at one or more temperatures in the range of about ambient temperature to 1000° C. or about 100° C. to 400° C. to convert the silicon nitride or carbon-doped silicon nitride film into a carbon-doped silicon oxynitride film in situ or in another chamber.

[0071] In yet another embodiment of the method described herein, a silicon nitride or carbon-doped silicon nitride film having a carbon content of less than 5 at.% is deposited using a plasma enhanced ALD process. In this embodiment, the method comprises:

[0072] a. placing one or more substrates comprising surface features into a reactor and heating the reactor to one or more temperatures ranging from ambient temperature to about 600° C., and optionally maintaining the reactor at a pressure of 100 Torr or less;

[0073] b. Introducing into the reactor at least one silicon precursor having one or two Si-C-Si bonds, which is selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapropane, 3-Pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane, 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane;

[0074] c. purging with an inert gas to remove any unreacted silicon precursor;

[0075] d. providing a first plasma containing / including an ammonia source into the reactor to react with the surface to form a silicon nitride or carbon-doped silicon nitride film;

[0076] e. Purge with inert gas to remove any reaction by-products;

[0077] f. providing a second plasma containing a nitrogen source to the reactor to react with the surface to form a silicon nitride or carbon-doped silicon nitride film;

[0078] g. purging with an inert gas to remove any reaction by-products; and

[0079] wherein steps b to g are repeated until a film of desired thickness is deposited. In certain embodiments, the method described herein further comprises.

[0080] In yet another embodiment of the method described herein, the silicon nitride or carbon-doped silicon nitride film has a carbon content of less than 5 at.% or less and is deposited using a plasma enhanced ALD process. In this embodiment, the method comprises:

[0081] a. placing one or more substrates comprising surface features into a reactor and heating the reactor to one or more temperatures ranging from ambient temperature to about 600° C., and optionally maintaining the reactor at a pressure of 100 Torr or less;

[0082] b. Introducing into the reactor at least one silicon precursor having one or two Si-C-Si bonds, which is selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3,3-hexachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3,3-hexachloro-2,2-dimethyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapropane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapropane, 3-Pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane, 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane;

[0083] c. purging with an inert gas to remove any unreacted silicon precursor;

[0084] d. providing a first plasma containing a nitrogen source into the reactor to react with the surface to form a silicon nitride or carbon-doped silicon nitride film;

[0085] e. Purge with inert gas to remove any reaction by-products;

[0086] f. providing a second plasma containing / including an ammonia source to the reactor to react with the surface to form a silicon nitride or carbon-doped silicon nitride film;

[0087] g. purging with an inert gas to remove any reaction by-products; and

[0088] Steps b to g are repeated until a film of desired thickness is deposited.

[0089] In one embodiment, the substrate comprises at least one feature, wherein the feature comprises a patterned trench having an aspect ratio of 1:9 or greater and an opening of 180 nm or less.

[0090] In yet another embodiment, a container for depositing a silicon-containing film comprises one or more silicon precursor compounds described herein. In a specific embodiment, the container is at least one pressurizable container (preferably a stainless steel container having a design such as disclosed in U.S. Patent Nos. US7334595; US6077356; US5069244; and US5465766, the disclosures of which are incorporated herein by reference). The container may comprise glass (borosilicate or quartz glass) or 316, 316L, 304 or 304L type stainless steel alloy (UNS designations S31600, S31603, S30400, S30403), equipped with suitable valves and fittings to deliver one or more precursors to the reactor for CVD or ALD processes. In this or other embodiments, the silicon precursor is provided in a pressurizable container composed of stainless steel, and the purity of the precursor is 98 wt % or more or 99.5 % or more, which is suitable for semiconductor applications. The silicon precursor compound is preferably substantially free of metal ions, such as Al 3+ Ion, Fe 2+ , Fe 3+ 、Ni 2+ Cr 3+. As used herein, the term "substantially free" when referring to Al, Fe, Ni, Cr means less than about 5ppm (weight) as determined by ICP-MS, preferably less than about 1ppm as determined by ICP-MS, and more preferably less than about 0.1ppm, and most preferably about 0.05ppm as determined by ICP-MS. In certain embodiments, if desired, such a container may also have a device for mixing the precursor with one or more additional precursors. In these or other embodiments, the contents of the container may be premixed with additional precursors. Alternatively, the silicon precursor and / or other precursors may be kept in separate containers, or in a single container having a separation device for keeping the silicon precursor and other precursors separate during storage.

[0091] The silicon-containing film is deposited on at least the surface of a substrate such as a semiconductor or display substrate. In the methods described herein, the substrate can be composed and / or coated with a variety of materials known in the art, including silicon such as crystalline silicon or amorphous silicon, silicon oxide, silicon nitride, amorphous carbon, silicon oxycarbide, silicon oxynitride, silicon carbide, germanium, germanium-doped silicon, boron-doped silicon, metals (such as copper, tungsten, aluminum, cobalt, nickel, tantalum), metal nitrides such as titanium nitride, tantalum nitride, metal oxides, III / V group metals or metalloids such as GaAs, InP, GaP and GaN, AMOLED (active matrix organic light emitting diode) flexible substrates (e.g., plastic substrates) and combinations thereof. These coatings can completely coat the semiconductor substrate, can be in multiple layers of various materials, and can be partially etched to expose the underlying material layer. The surface can also have a photoresist material thereon, which is exposed with a pattern and developed to partially coat the substrate. In certain embodiments, the semiconductor substrate comprises at least one surface feature selected from holes, through holes, grooves and combinations thereof. Potential applications of silicon-containing films include, but are not limited to, low-k spacers for FinFETs or nanosheets, sacrificial hardmasks for self-aligned patterning processes (eg, SADP, SAQP, or SAOP).

[0092] The deposition method for forming a silicon-containing film or coating is a deposition process. Examples of suitable deposition processes for the methods disclosed herein include, but are not limited to, chemical vapor deposition or atomic layer deposition processes. As used herein, the term "chemical vapor deposition process" refers to any process in which a substrate is exposed to one or more volatile precursors, which react and / or decompose on the substrate surface to produce the desired deposition. As used herein, the term "atomic layer deposition process" refers to a self-limiting (e.g., the amount of film material deposited in each reaction cycle is constant), sequential surface chemistry, which deposits a film of material onto a substrate of different composition. As used herein, the term "thermal atomic layer deposition process" refers to an atomic layer deposition process performed at a substrate temperature ranging from room temperature to 600°C without an in-situ or remote plasma. Although the precursors, reagents, and sources used herein may sometimes be described as "gaseous", it should be understood that the precursor may be a liquid or solid, which may be delivered to the reactor by direct vaporization, bubbling, or sublimation with or without an inert gas. In some cases, the vaporized precursor may be passed through a plasma generator.

[0093] In one embodiment, the silicon-containing film is deposited using an ALD process. In another embodiment, the silicon-containing film is deposited using a CCVD process. In another embodiment, the silicon-containing film is deposited using a thermal ALD process. As used herein, the term "reactor" includes, but is not limited to, a reaction chamber or a deposition chamber.

[0094] In certain embodiments, the method disclosed herein avoids the pre-reaction of the precursor by using an ALD or cyclic CVD method that separates the precursor before and / or during the introduction into the reactor. Preferably, a deposition technique such as an ALD or CCVD process is used to deposit a silicon-containing film. In one embodiment, the film is deposited in a typical single-chip ALD reactor, a semi-batch ALD reactor or a batch furnace ALD reactor by an ALD process by exposing the substrate surface alternately to one or more silicon-containing precursors, oxygen sources, nitrogen-containing sources or other precursors or reagents. Film growth is carried out by self-limiting control of surface reactions, the pulse length of each precursor or reagent, and the deposition temperature. However, once the substrate surface is saturated, the growth of the film stops. In another embodiment, each reactant including a silicon precursor and a reactive gas is exposed to the substrate by moving or rotating the substrate to different sections of the reactor, and each section is separated by an inert gas curtain (i.e., a spatial ALD reactor or a roll-to-roll ALD reactor).

[0095] In certain embodiments, depending on the deposition method, the silicon precursors described herein and optionally other silicon-containing precursors may be introduced into the reactor in predetermined molar amounts (e.g., from about 0.1 to about 1000 micromoles). In this or other embodiments, the precursors may be introduced into the reactor within a predetermined time period. In certain embodiments, the time period is in the range of from about 0.001 seconds to about 500 seconds.

[0096] In certain embodiments, the silicon nitride or carbon-doped silicon film deposited by the methods described herein is treated with an oxygen source, an oxygen-containing reagent or precursor (e.g., water vapor) to convert such a film into a carbon-doped oxynitride. The oxygen source may be introduced into the reactor in the form of at least one oxygen source and / or may be incidentally present in other precursors used during the deposition process. Suitable oxygen source gases may include, for example, air, water (H2O) (e.g., deionized water, purified water, distilled water, water vapor, water vapor plasma, hydrogen peroxide, oxidized water, air, a composition comprising water and other organic matter), oxygen (O2), oxygen plasma, ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), nitrous oxide (N2O), carbon monoxide (CO), hydrogen peroxide (H2O2), a plasma comprising water, a plasma comprising water and argon, hydrogen peroxide, a composition comprising hydrogen, a composition comprising hydrogen and oxygen, carbon dioxide (CO2), air, and combinations thereof. In certain embodiments, the oxygen source comprises an oxygen source gas introduced into the reactor at a flow rate ranging from about 1 to about 10,000 standard cubic centimeters (sccm) or from about 1 to about 1000 sccm. The oxygen source may be introduced for a time ranging from about 0.1 seconds to about 100 seconds. The catalyst is selected from a Lewis base, such as pyridine, piperazine, trimethylamine, tert-butylamine, diethylamine, trimethylamine, ethylenediamine, ammonia or other organic amines.

[0097] In embodiments where the film is deposited by an ALD or cyclic CVD process, the precursor pulse may have a pulse duration greater than 0.01 seconds, and the oxygen source may have a pulse duration less than 0.01 seconds, and the water pulse duration may have a pulse duration less than 0.01 seconds.

[0098] In certain embodiments, the oxygen source flows continuously into the reactor while the precursor pulse and plasma are introduced sequentially. The precursor pulse may have a pulse duration greater than 0.01 seconds, while the plasma duration may be in the range of 0.01 seconds to 100 seconds.

[0099] In certain embodiments, the silicon-containing film comprises silicon and nitrogen. In these embodiments, the silicon-containing film deposited using the methods described herein is formed in the presence of a nitrogen-containing source. The nitrogen-containing source can be introduced into the reactor in the form of at least one nitrogen source gas and / or can be incidentally present in other precursors used during the deposition process.

[0100] Suitable ammonia-containing gases may include, for example, ammonia, a mixture of ammonia and an inert gas, a mixture of ammonia and nitrogen, a mixture of ammonia and hydrogen, and combinations thereof.

[0101] In certain embodiments, a nitrogen source is introduced into the reactor at a flow rate ranging from about 1 to about 10,000 standard cubic centimeters (sccm) or from about 1 to about 1000 sccm. The nitrogen-containing source may be introduced for a time range of from about 0.1 to about 100 seconds. In embodiments where a film is deposited by an ALD or cyclic CVD process using nitrogen and oxygen sources, the precursor pulse may have a pulse duration greater than 0.01 seconds, and the nitrogen source may have a pulse duration less than 0.01 seconds, and the water pulse duration may have a pulse duration less than 0.01 seconds. In yet another embodiment, the purge duration between pulses may be as low as 0 seconds or continuous pulses without purging in between.

[0102] Deposition methods disclosed herein include one or more steps of purging unwanted or unreacted materials from a reactor using a purge gas. The purge gas used to purge unconsumed reactants and / or reaction byproducts is an inert gas that does not react with a precursor. Exemplary purge gases include, but are not limited to, argon (Ar), nitrogen (N2), helium (He), neon (Ne), hydrogen (H2) and combinations thereof. In certain embodiments, a purge gas such as Ar is supplied to the reactor at a flow rate from about 10 to about 10000sccm for about 0.1 to 1000 seconds, thereby purging unreacted materials and any byproducts that may remain in the reactor.

[0103] The respective steps of supplying precursors, oxygen sources, ammonia-containing sources and / or other precursors, source gases and / or reagents may be performed by varying the time for supplying them to change the stoichiometric composition of the resulting film.

[0104] Energy is applied to at least one of the precursor, the ammonia source, the reducing agent (e.g., hydrogen plasma), other precursors, or a combination thereof to induce a reaction and form a film or coating on the substrate. Such energy can be provided by, but is not limited to, thermal, plasma, pulsed plasma, helicon plasma, high density plasma, inductively coupled plasma, X-ray, electron beam, photon, remote plasma methods, and combinations thereof.

[0105] In certain embodiments, a secondary RF source may be used to change the plasma characteristics at the substrate surface. In embodiments where the deposition involves plasma, the plasma generation process may include a direct plasma generation process where the plasma is generated directly in the reactor, or alternatively, a remote plasma generation process where the plasma is generated outside the reactor and supplied to the reactor.

[0106] Silicon precursors and / or other silicon-containing precursors can be delivered to a reaction chamber, such as a CVD or ALD reactor, in various ways. In one embodiment, a liquid delivery system can be utilized. In an optional embodiment, a combined liquid delivery and flash processing unit can be used, such as, for example, a turbo vaporizer manufactured by MSP Corporation of Shoreview, MN, so that low-volatile materials can be quantitatively delivered, which results in repeatable delivery and deposition without thermal decomposition of the precursor. In the liquid delivery mode, the precursors described herein can be delivered in pure liquid form, or alternatively, can be used in a solvent formulation or a composition comprising the same. Therefore, in certain embodiments, the precursor formulation may include a solvent component having appropriate properties, such as may be desired and advantageous in a given end-use application, to form a film on a substrate.

[0107] In this or other embodiments, it should be understood that the steps of the methods described herein can be performed in various orders, can be performed sequentially or simultaneously (e.g., during at least a portion of another step), and any combination thereof. The respective steps of supplying the precursor and nitrogen-containing source gas can be performed by varying the duration for supplying them to change the stoichiometric composition of the resulting silicon-containing film.

[0108] In still further embodiments of the methods described herein, the film or the film so deposited is subjected to a treatment step. The treatment step may be performed during at least a portion of the deposition step, after the deposition step, and combinations thereof. Exemplary treatment steps include, but are not limited to, treatment by high temperature thermal annealing; plasma treatment; ultraviolet (UV) light treatment; laser; electron beam treatment, and combinations thereof, to affect one or more properties of the film. The film deposited with the silicon precursor having one or two Si-C-Si bonds described herein has improved properties, such as, but not limited to, a wet etch rate that is lower than the wet etch rate of the film before the treatment step or a density that is higher than the density before the treatment step, compared to a film deposited with a previously disclosed silicon precursor under the same conditions. In a specific embodiment, the film so deposited is subjected to intermittent treatments during the deposition process. These intermittent or in-deposition treatments may be performed, for example, after each ALD cycle, after a certain number of ALD cycles, such as, but not limited to, after one (1) ALD cycle, two (2) ALD cycles, five (5) ALD cycles, or after every ten (10) or more ALD cycles.

[0109] In embodiments where the film is treated with a high temperature annealing step, the annealing temperature is at least 100° C. greater than the deposition temperature. In this or other embodiments, the annealing temperature is in the range of about 400° C. to about 1000° C. In this or other embodiments, the annealing process can be performed in a vacuum (<760 Torr), an inert environment, or an oxygen-containing environment (e.g., ozone, H2O, H2O2, N2O, NO2, or O2).

[0110] In embodiments where the film is UV treated, the film is exposed to a broadband UV or alternatively a UV source having a wavelength ranging from about 150 nanometers (nm) to about 400 nm. In a specific embodiment, after the desired film thickness is reached, the film so deposited is exposed to UV in a chamber different from the deposition chamber.

[0111] In embodiments where the film is treated with plasma, a passivation layer such as carbon doped silicon oxide is deposited to prevent chlorine and nitrogen contamination from penetrating the film during subsequent plasma treatment. The passivation layer may be deposited using atomic layer deposition or cyclic chemical vapor deposition.

[0112] In embodiments where the film is treated with plasma, the plasma source is selected from hydrogen plasma, plasma containing hydrogen and helium, plasma containing hydrogen and argon. Hydrogen plasma reduces the dielectric constant of the film and enhances resistance to damage by subsequent plasma ashing processes, while still leaving the carbon content in the bulk almost unchanged.

[0113] The following examples illustrate certain aspects of the invention and do not limit the scope of the appended claims. Example

[0114] In the following examples, unless otherwise stated, properties are obtained from sample films deposited on silicon wafers with a resistivity of 5-20 Ω-cm as substrate.All film depositions were performed using a CN-1 reactor of showerhead design with a 13.56 MHz direct plasma.

[0115] Under typical process conditions, unless otherwise stated, the chamber pressure is fixed at a pressure ranging from about 1 to about 5 Torr. Additional inert gas is used to maintain the chamber pressure.

[0116] Film deposition included the steps listed in Tables 3, 4 and 5 for plasma enhanced ALD. Unless otherwise stated, a total of 100 or 200 or 300 or 500 deposition cycles were used to obtain the desired film thickness.

[0117] Table 3. Deposition steps in PEALD silicon nitride or carbon-doped silicon nitride films

[0118]

[0119] Table 4. Deposition steps in PEALD silicon nitride or carbon-doped silicon nitride films

[0120]

[0121]

[0122] Table 5: Deposition steps in PEALD silicon nitride or carbon-doped silicon nitride films

[0123]

[0124] The refractive index (RI) and thickness of the deposited film were measured using an ellipsometer. The film non-uniformity was calculated using the standard formula: % non-uniformity = ((maximum thickness - minimum thickness) / (2 * average (avg) thickness)). The structure and composition of the film were analyzed using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The density of the film was measured by X-ray reflectometry (XRR).

[0125] Example 1: ALD Silicon Nitride Using 1,1,1,3,3-Pentachloro-1,3-Disilabutane and NH3 / Argon Plasma

[0126] The silicon wafer was loaded into a CN-1 reactor equipped with a showerhead design with a 13.56 MHz direct plasma with a chamber pressure of 1 Torr. 1,1,1,3,3-pentachloro-1,3-disilabutane as a silicon precursor was delivered into the reactor in vapor form using bubbling or vapor pumping.

[0127] The ALD cycle consisted of the process steps provided in Table 3 and used the following process parameters:

[0128] a. Provide a substrate in a reactor and heat the substrate to about 300°C

[0129] b. Introducing 1,1,1,3,3-pentachloro-1,3-disilabutane vapor into the reactor

[0130] Argon flow: 100 sccm through the precursor container

[0131] Pulse: 2 seconds

[0132] Ar gas flow: 1000 sccm

[0133] c.Purge

[0134] Argon flow: 1000sccm

[0135] Purge time: 10 seconds

[0136] d. Introducing ammonia plasma

[0137] Argon flow: 1000sccm

[0138] Ammonia flow: 300sccm

[0139] Plasma power: 300W

[0140] Pulse: 15 seconds

[0141] e.Purge

[0142] Argon flow: 1000sccm

[0143] Purge time: 5 seconds

[0144] Steps b to e were repeated for 1000 cycles to provide 32 nm of silicon nitride with a composition of 58.66 at.% nitrogen, 38.96 at.% silicon and 2.37 at.% oxygen. Chlorine and carbon were both undetectable. The refractive index was about 1.9.

[0145] Example 2: ALD Silicon Nitride Using 1,1,1,3,3-Pentachloro-1,3-Disilabutane and NH3 / Argon Plasma

[0146] The silicon wafers were loaded into a CN-1 reactor equipped with a showerhead design with a 13.56 MHz direct plasma with a chamber pressure of 1 Torr. 1,1,1,3,3-pentachloro-1,3-disilabutane was delivered to the reactor in vapor form using bubbling.

[0147] The ALD cycle consisted of the process steps given in Table 1 and used the following process parameters:

[0148] a) providing a substrate in a reactor and heating the substrate to about 400° C.;

[0149] b) introducing 1,1,1,3,3-pentachloro-1,3-disilabutane vapor into a reactor;

[0150] Argon flow: 100 sccm through the precursor container

[0151] Pulse: 2 seconds

[0152] Argon: 1000sccm

[0153] c) Inert gas purge

[0154] Argon flow: 1000sccm

[0155] Purge time: 15 seconds

[0156] d) Introducing ammonia plasma

[0157] Argon flow: 1000sccm

[0158] Ammonia flow: 50sccm

[0159] Plasma power: 300W

[0160] Pulse: 10 seconds

[0161] e) Purge

[0162] Argon flow: 1000sccm

[0163] Purge time: 10 seconds

[0164] Steps b to e were repeated for 1000 cycles to provide 26 nm of silicon nitride with a composition of 58.30 at.% nitrogen, 39.15 at.% silicon, 2.55 at.% oxygen. Chlorine and carbon were not detectable by XPS measurement. The composition of the resulting film in this working example was close to stoichiometric silicon nitride. The refractive index was about 1.9.

[0165] Although the present invention has been illustrated and described above with reference to certain specific embodiments and working examples, it is not intended that the present invention be limited to the details shown. Rather, various modifications may be made in detail within the limits and scope of equivalents of the claims without departing from the spirit of the present invention. It is expressly intended that, for example, all ranges broadly referred to herein include within their limits all narrower ranges falling within the broader ranges.

Claims

1. A method for forming silicon nitride by a plasma enhanced ALD process, the method comprising: a) providing a substrate comprising surface features in a reactor and heating the reactor to one or more temperatures up to 600° C.; b) at least one compound having one or two Si-C-Si bonds and selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilapentane, introducing a silicon precursor of methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane, 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane into the reactor, thereby reacting the silicon precursor on at least a portion of the surface features of the substrate to provide a chemical adsorption layer; c) purging any unreacted silicon precursor and / or reaction byproducts in the reactor with an inert gas; d) providing plasma containing an ammonia source into the reactor to react with the chemical adsorption layer to form a silicon nitride film; and e) purging the reactor of any further reaction byproducts with an inert gas; Steps b to e are repeated until a desired thickness of the silicon nitride film is deposited, wherein the formed film has a carbon content of less than 5 atomic weight % as measured by X-ray photoelectron spectroscopy.

2. The method of claim 1, further comprising maintaining the reactor at a pressure of 100 Torr or less. The method according to claim 1 , wherein the silicon nitride film is a carbon-doped silicon nitride film.

4. The method according to claim 1, further comprising: The silicon nitride film is treated with a spike anneal at a temperature ranging from 400 to 1000°C.

5. The method according to claim 1, further comprising: During or after deposition of the silicon nitride film, the silicon nitride film is exposed to a UV light source.

6. The method according to claim 1, further comprising: The silicon nitride film is exposed to a plasma comprising one or more gases selected from the group consisting of hydrogen, an inert gas, nitrogen, and combinations thereof.

7. The method according to claim 1, further comprising: The silicon nitride film is treated with an oxygen source, either in situ or in a chamber separate from the reactor, at one or more temperatures ranging from ambient temperature to 1000° C. to convert the silicon nitride into a silicon oxynitride film.

8. The method of claim 7, wherein the silicon nitride film is a carbon-doped silicon nitride film, and wherein the step of treating the silicon nitride film with an oxygen source converts the carbon-doped silicon nitride into a carbon-doped silicon oxynitride film.

9. The method of claim 1, wherein the formed film has a dielectric constant (k) of 6 or less.

10. The method of claim 9, wherein the formed film has a carbon content of 3 atomic weight percent or less as measured by X-ray photoelectron spectroscopy.

11. The method of claim 10, wherein the formed film has a carbon content of 2 atomic weight percent or less as measured by X-ray photoelectron spectroscopy. 12 . The method according to claim 11 , wherein the formed film has a carbon content of 1 atomic weight percent or less as measured by X-ray photoelectron spectroscopy.

13. The method of claim 1, further comprising thermally annealing the silicon nitride film at a temperature of 300 to 1000°C.

14. The method of claim 1, further comprising plasma treating the silicon nitride film with an inert gas plasma or a hydrogen / inert plasma or a nitrogen plasma at a temperature ranging from 25°C to 600°C.

15. The method of claim 3, further comprising plasma treating the carbon-doped silicon nitride film with an inert gas plasma or a hydrogen / inert plasma or a nitrogen plasma at a temperature in a range of 25°C to 600°C.

16. The method of claim 7, further comprising plasma treating the silicon oxynitride film with inert gas plasma or hydrogen / inert plasma or nitrogen plasma at a temperature in a range of 25°C to 600°C.

17. The method of claim 8, further comprising plasma treating the carbon-doped silicon oxynitride film with inert gas plasma or hydrogen / inert plasma or nitrogen plasma at a temperature in a range of 25°C to 600°C.

18. A method for forming silicon nitride by a plasma enhanced ALD process, the method comprising: a) providing a substrate comprising surface features in a reactor; b) introducing into the reactor at least one solvent having one or two Si-C-Si bonds and selected from 1,1,1,3,3-pentachloro-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2,2-dimethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilabutane, 1,1,1,3,3-pentachloro-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-methyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, a silicon precursor of chloro-2,2-dimethyl-1,3-disilapentane, 1,1,1,3,3-pentachloro-2-ethyl-1,3-disilapentane, 1,1,1,3,3,5,5-heptachloro-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-3,3-dimethyl-1,3,5-trisilahexane, 1,1,1,5,5-pentachloro-1,3,5-trisilahexane, and 2,2,4,6,6-pentachloro-4-methyl-2,4,6-trisilaheptane, thereby reacting the silicon precursor on at least a portion of a surface feature of the substrate to provide a chemisorbed layer; c) purging any unreacted silicon precursor and / or any reaction byproducts in the reactor with an inert gas; d) providing a first plasma source into the reactor to react with the chemical adsorption layer to form a silicon nitride film or a carbon-doped silicon nitride film; e) purging the reactor of any further reaction byproducts with an inert gas; f) providing a second plasma source into the reactor to further react and form a silicon nitride film or a carbon-doped silicon nitride film; g) purging the reactor with an inert gas for any further reaction byproducts; wherein steps b to g are repeated until the silicon nitride film or carbon-doped silicon nitride film reaches a desired thickness, and wherein the reactor is maintained at one or more temperatures in the range of 25° C. to 600° C., wherein the formed film has a carbon content of less than 5 atomic weight % as measured by X-ray photoelectron spectroscopy.

19. The method of claim 18, wherein the plasma is a plasma comprising an ammonia source, and the second plasma is a plasma comprising a nitrogen source.

20. The method of claim 18, wherein the first plasma is a plasma comprising a nitrogen source, and the second plasma is a plasma comprising an ammonia source.

21. The method of claim 1 or 18, wherein the formed film is suitable for use in semiconductor industry or display applications.

22. The method of claim 18, wherein the silicon nitride film is a carbon-doped silicon nitride film.

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