Method for preparing films containing silicon and nitrogen

Abstract

Disclosed are a composition for use in the manufacture of electronic devices and a method for using the composition. Also disclosed are compounds, compositions and methods for depositing high-quality silicon nitride or carbon-doped silicon nitride.

Description

[0001] This case is a divisional application of the patent application with application number 201910809779.4 filed by the present applicant on August 29, 2019 and entitled “Method for Preparing Silicon and Nitrogen-Containing Films”. The entire contents of the parent case are incorporated into this divisional application by reference.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Application No. 62 / 724,205, filed on August 29, 2018, the entire contents of which are incorporated herein by reference for all permitted purposes. Technical Field

[0004] 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 with high dielectric constant (<7.0) and high oxygen ash resistance, such as but not limited to stoichiometric silicon nitride, carbon-doped silicon nitride films and carbon-doped silicon oxynitride films. Background Art

[0005] Silicon nitride films are used in semiconductors for various applications. For example, silicon nitride films are used as final passivation and mechanical protection layers for integrated circuits, mask layers for selective silicon oxidation, as one of the dielectric materials in the stacked oxide-nitride-oxide (ONO) layers 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 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 above 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 SiliconDioxide and SiliconOxynitride 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 in the temperature range of 600-850° C. The deposited silicon dioxide and silicon oxynitride films exhibit 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) describes a low temperature process with good step coverage of silicon nitride (SiN) formed by low pressure chemical vapor deposition (LPCVD) using hexachlorodisilane (HCD).

[0009] JP2000100812 describes a method for depositing films using SiCl4 and NH3 as source gases. Before deposition, the substrate surface can be nitrided using NH3. An extremely thin film with improved insulator properties is formed. Silicon nitride films can be used as capacitor insulator films for semiconductor integrated circuits.

[0010] US Patent No. 6,355,582 describes a method of forming a silicon nitride film, in which a substrate to be subjected to film formation 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 including silicon nitride on the structure with a height difference. Forming the first dielectric layer includes supplying a first gas including pentachlorodisilane (PCDS) or diisopropylamine pentachlorodisilane (DPDC) as a silicon precursor and a second gas including a nitrogen component into a chamber including 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, devices containing the silicon-heteroatom compounds, methods for preparing chlorodisilazanes, silicon-heteroatom compounds and devices; and uses of chlorodisilazanes, silicon-heteroatom compounds and devices.

[0013] PCT Publication No. WO2018057677 discloses a composition comprising trichlorodisilane as a silicon precursor for forming a film. The composition comprises 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 publication also discloses a method for forming a silicon-containing film on a substrate using a silicon precursor compound and a 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 halogen silane 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. Publication No. 2009 / 0155606 discloses a cyclic method for depositing a silicon nitride film on a substrate. In one embodiment, the 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 a high deposition rate. The resulting silicon nitride film has relatively few impurities and a higher quality. In addition, a silicon nitride film having good step coverage on features with a high aspect ratio and having a thin and uniform thickness can be formed.

[0016] There is a need in the art to provide compositions and methods 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 within 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 silicon 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) to improve one or more film properties, such as, but not limited to, purity and / or density, in a CVD, ALD, or ALD-like process.

[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 compositions for depositing silicon nitride or carbon-doped silicon nitride and methods of using the same having the following characteristics: a) a carbon content of about 5 atomic % or less, about 3 atomic % or less, preferably about 2 atomic % or less, about 1 atomic % or less, as measured by X-ray photoelectron spectroscopy (XPS), preferably stoichiometric silicon nitride; 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); a step coverage of 90% or more, 95% or more, 99% or more, and a dielectric constant of 7.0 or less, 6.0 or less, and 5.0 or less. Summary of the invention

[0020] The above needs are met in one aspect by providing a method for forming a carbon-doped silicon nitride film via a plasma ALD process. According to the method, a substrate including surface features is introduced into a reactor. The reactor is heated to one or more temperatures in a temperature range of up to about 550°C, preferably one or more temperatures of 300°C or less. The reactor can be maintained at a pressure of 100 Torr or less. At least one silicon precursor having two Si-C-Si bonds is introduced into the reactor to form a silicon-containing material on the substrate, the silicon precursor being selected from 1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-1,3-disilacyclobutane, 1,3-dibromo-1,3-disilacyclobutane, 1,1,3-trichloro-1,3-disilacyclobutane, 1,1,3- 3-Tribromo-1,3-disilacyclobutane, 1,1,3,3-tetrachloro-1,3-disilacyclobutane, 1,1,3,3-tetrabromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane, 1,3-dibromo-1,3-dimethyl-1,3-disilacyclobutane, 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilane Heteropentane, 1,1,3,3,5,5-hexachloro-1,5-dimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane, 1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane, 1,1 ,5,5-tetrachloro-1,3,5-trisilapentane, 1-iodo-1,3-disilacyclobutane, 1,1-diiodo-1,3-disilacyclobutane, 1,3-diiodo-1,3-disilacyclobutane, 1,1,3-triiodo-1,3-disilacyclobutane, 1,1,3,3-tetraiodo-1,3-disilacyclobutane and 1,3-diiodo-1,3-dimethyl-1,3-disilacyclobutane.

[0021] The reactor is purged of any unconsumed precursor and / or reaction byproducts with a suitable inert gas. A plasma comprising nitrogen is introduced into the reactor to react with the silicon-containing species to form a carbon-doped silicon nitride film.

[0022] Next, the reactor is purged again with a suitable inert gas for any reaction byproducts. The steps of introducing precursors, purging as needed, introducing plasma, and purging again as needed are repeated as needed to deposit a carbon-doped silicon nitride film to a predetermined thickness.

[0023] The above needs and other needs are further met by a method for forming silicon nitride, carbon-doped silicon nitride or carbon-doped silicon oxynitride films via a plasma ALD process. According to the method, a substrate including surface features is introduced into a reactor. The reactor is heated to one or more temperatures in the range of up to about 550°C, preferably one or more temperatures of 300°C or less. The reactor can be maintained at a pressure of 100 Torr or less. At least one silicon precursor having two Si-C-Si bonds is introduced into the reactor to form a silicon-containing substance on the substrate, the silicon precursor being selected from 1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-1,3-disilacyclobutane, 1,3-dibromo-1,3-disilacyclobutane, 1,1,3-trichloro-1,3-disilacyclobutane, 1,1,3- 3-Tribromo-1,3-disilacyclobutane, 1,1,3,3-tetrachloro-1,3-disilacyclobutane, 1,1,3,3-tetrabromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane, 1,3-dibromo-1,3-dimethyl-1,3-disilacyclobutane, 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilane Heteropentane, 1,1,3,3,5,5-hexachloro-1,5-dimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane, 1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane, 1,1 ,5,5-tetrachloro-1,3,5-trisilapentane, 1-iodo-1,3-disilacyclobutane, 1,1-diiodo-1,3-disilacyclobutane, 1,3-diiodo-1,3-disilacyclobutane, 1,1,3-triiodo-1,3-disilacyclobutane, 1,1,3,3-tetraiodo-1,3-disilacyclobutane and 1,3-diiodo-1,3-dimethyl-1,3-disilacyclobutane.

[0024] The reactor is purged of any unconsumed precursor and / or reaction byproducts with a suitable inert gas. A plasma containing an ammonia source is introduced into the reactor to react with the silicon-containing species to form a silicon nitride or carbon-doped silicon nitride film.

[0025] Next, the reactor is purged again with a suitable inert gas for any reaction byproducts. The steps of introducing the precursor, purging as needed, introducing the 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.

[0026] Optionally, the resulting silicon nitride or carbon-doped silicon nitride film is then exposed to an oxygen source at one or more temperatures ranging from approximately 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.

[0027] The present invention also includes the following items:

[0028] 1. A method for forming a film containing silicon and nitrogen by a plasma enhanced ALD process, the method comprising:

[0029] a) providing a substrate comprising surface features in a reactor;

[0030] b) heating the reactor to one or more temperatures in the range of up to about 600° C. and optionally maintaining the reactor at a pressure of 100 Torr or less;

[0031] c) introducing into the reactor at least one silicon precursor having two Si-C-Si bonds and selected from the group consisting of 1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-disilacyclobutane, 1,3-dibromo-1,3-disilacyclobutane, 1,1,3-trichloro-1,3-disilacyclobutane, 1,1,3-tribromo-1,3-disilacyclobutane alkane, 1,1,3,3-tetrachloro-1,3-disilacyclobutane, 1,1,3,3-tetrabromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane, 1,3-dibromo-1,3-dimethyl-1,3-disilacyclobutane, 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane, 1,1,3,3,5, 5-Hexachloro-1,5-dimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-Hexachloro-3,3-dimethyl-1,3,5-trisilapentane, 1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-Hexachloro-1,3,5-trisilapentane, 1,1,5,5-Tetrachloro-1,3,5- trisilapentane, 1-iodine-1,3-disilacyclobutane, 1,1-diiodine-1,3-disilacyclobutane, 1,3-diiodine-1,3-disilacyclobutane, 1,1,3-triiodine-1,3-disilacyclobutane, 1,1,3,3-tetraiodine-1,3-disilacyclobutane and 1,3-diiodine-1,3-dimethyl-1,3-disilacyclobutane to form a silicon-containing substance on the substrate;

[0032] d) purging the reactor of any unreacted silicon precursor and / or any reaction byproducts from step c using a first inert gas;

[0033] e) providing a plasma containing an ammonia source into the reactor to react with the silicon-containing substance to form a silicon nitride film;

[0034] f) purging the reactor of any further reaction by-products from step e with a second inert gas; and

[0035] g) Repeat steps c to f as needed to make the silicon nitride film reach a predetermined thickness.

[0036] 2. The method according to item 1, wherein the silicon nitride film is a carbon-doped silicon nitride film.

[0037] 3. The method according to item 1 or 2, further comprising:

[0038] The silicon nitride film is treated with a spike anneal at a temperature ranging from 400 to 1000°C.

[0039] 4. The method according to any one of items 1 to 3, further comprising:

[0040] The silicon nitride film is exposed to a UV light source during or after deposition of the silicon nitride film.

[0041] 5. The method according to any one of items 1 to 4, further comprising:

[0042] The silicon nitride film is exposed to a plasma containing hydrogen or an inert gas or nitrogen.

[0043] 6. The method according to any one of items 1 to 5, further comprising:

[0044] The silicon nitride film is treated with an oxygen source 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.

[0045] 7. The method according to item 6, wherein the silicon nitride film is a carbon-doped silicon nitride film, and wherein the step of treating with an oxygen source converts the carbon-doped silicon nitride into a carbon-doped silicon oxynitride film.

[0046] 8. A film formed according to the method of any of items 1-7, having a dielectric constant (k) of about 7 or less, an oxygen content of about 5 at.% or less, and a carbon content of about 5 at.% or less, as measured by X-ray photoelectron spectroscopy.

[0047] 9. The film of item 8, having a carbon content of about 3 atomic weight % or less as measured by X-ray photoelectron spectroscopy.

[0048] 10. The film of item 9, having a carbon content of about 2 atomic weight % or less as measured by X-ray photoelectron spectroscopy.

[0049] 11. The film of item 10, having a carbon content of about 1 atomic weight % or less as measured by X-ray photoelectron spectroscopy.

[0050] 12. The method according to item 1 or 2, further comprising thermally annealing the silicon nitride film or the carbon-doped silicon nitride film at a temperature of 300°C to 1000°C.

[0051] 13. The method according to item 1, 2, 6 or 7 further includes plasma treating the silicon nitride film or the carbon-doped silicon nitride film or the silicon oxynitride film or the carbon-doped silicon oxynitride film with inert gas plasma or hydrogen / inert gas plasma or nitrogen plasma at a temperature in the range of 25°C to 600°C.

[0052] 14. The method according to any one of items 1-7 and 12-13, further comprising:

[0053] h) providing a plasma containing a nitrogen source into the reactor to react with the silicon-containing substance and further form the silicon nitride film; and

[0054] i) purging the reactor of any further reaction by-products with a second inert gas,

[0055] Step g) in which steps c to f are repeated further comprises repeating steps h and i, so that steps c to i are repeated as necessary to allow the silicon nitride film to reach a predetermined thickness.

[0056] 15. The film according to item 14, having a dielectric constant (k) of about 7 or less, an oxygen content of about 5 at.% or less, a carbon content of about 5 at.% or less, and a density of about 2.7 g / cm 3 or higher. DETAILED DESCRIPTION

[0057] 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 introduced into a reactor in sequence, such as 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 parts of the reactor, and each part is separated by an inert gas curtain, i.e., a spatial ALD reactor or a roll-to-roll ALD reactor.

[0058] Throughout the specification, the term "plasma comprising 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.

[0059] 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.

[0060] Throughout the specification, the term "ashing" refers to the process of removing photoresist or carbon hard mask in a semiconductor manufacturing process 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).

[0061] 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 7; bulk carbon content (more than 1% in the film) Depth) within 5at.% before ashing; less than The membrane is damaged, such as by approaching the surface (less than Depth) and body (greater than The difference in dilute HF etching rate between films with different depths was observed.

[0062] Throughout the specification, the term "alkyl hydrocarbon" refers to a linear or branched C1 to C 20 Hydrocarbons, cyclic C6 to C 20 Hydrocarbons. Exemplary hydrocarbons include, but are not limited to, heptane, octane, nonane, decane, dodecane, cyclooctane, cyclononane, cyclodecane.

[0063] Throughout the specification, the term "aromatic hydrocarbons" refers to C6 to C 20 Aromatic hydrocarbons. Exemplary aromatic hydrocarbons include, but are not limited to, toluene and mesitylene.

[0064] Throughout the specification, the term "inert gas" refers to a non-reactive gas. Exemplary inert gases include, but are not limited to, helium, argon, neon, nitrogen, and combinations thereof.

[0065] Throughout the specification, the term "step coverage" as used herein is defined as the percentage of two thicknesses of a deposited film in a structured or feature substrate having a via or trench or both, wherein the bottom step coverage is the ratio (in %) of the thickness at the bottom of the feature divided by the thickness at the top of the feature, and the intermediate step coverage is the ratio (in %) of the thickness at the sidewall of the feature divided by the thickness at the top of the feature. Films deposited using the methods described herein exhibit step coverage of about 80% or more, or about 90% or more, indicating that the film is conformal.

[0066] Throughout the specification, the term "plasma comprising nitrogen / nitrogen source" 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.

[0067] Described herein are silicon precursor compositions for depositing silicon nitride or carbon-doped silicon nitride having the following properties 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 less, as measured by X-ray photoelectron spectroscopy (XPS), preferably stoichiometric silicon nitride; 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.

[0068] In one aspect, the composition for depositing a silicon-containing film comprises: (a) at least one silicon precursor compound having one Si-C-Si or two Si-C-Si bonds selected from the group consisting of 1,1,1,3,3,3-hexachloro-1,3-disilapropane, 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, 1,1,1,3,3,3-hexachloro-2-ethyl-1,3-disilapropane Propane, 1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-1,3-disilacyclobutane, 1,3-dibromo-1,3-disilacyclobutane, 1,1,3-trichloro-1,3-disilacyclobutane, 1,1,3-tribromo-1,3-disilacyclobutane, 1,1,3,3-tetrachloro-1,3-disilacyclobutane, 1,1,3,3-tetrabromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-dimethyl-1,3 -disilacyclobutane, 1,3-dibromo-1,3-dimethyl-1,3-disilacyclobutane, 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane, 1,1,3,3,5,5-hexachloro-1,5-dimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane, 1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane, 1,1,1 ,5,5,5-hexachloro-1,3,5-trisilapentane, 1,1,5,5-tetrachloro-1,3,5-trisilapentane, 1-iodine-1,3-disilacyclobutane, 1,1-diiodine-1,3-disilacyclobutane, 1,3-diiodine-1,3-disilacyclobutane, 1,1,3-triiodine-1,3-disilacyclobutane, 1,1,3,3-tetraiodine-1,3-disilacyclobutane and 1,3-diiodine-1,3-dimethyl-1,3-disilacyclobutane, and (b) at least one solvent.

[0069] Table 1. Silicon precursors with one Si-C-Si bond

[0070]

[0071]

[0072] Table 2. Silicon precursors with two Si-C-Si bonds

[0073]

[0074]

[0075] And in at least one aspect of the present invention, (b) optionally at least one solvent. 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 lower. The wt% of the silicon precursor compound in the solvent may be 1 to 99wt%, or 10 to 90wt%, or 20 to 80wt%, or 30 to 70wt%, or 40 to 60wt%, or 50 to 50wt%. In some embodiments, the composition can be delivered by direct liquid injection into a reaction chamber for a silicon-containing film using conventional direct liquid injection equipment and methods.

[0076] In one embodiment of the method described herein, a silicon nitride or carbon-doped silicon nitride film having a carbon content of less than 5 at.% or less is deposited using a plasma enhanced ALD process. In this embodiment, the method comprises:

[0077] a. placing one or more substrates including surface features into a reactor;

[0078] b. 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;

[0079] c. introducing into the reactor at least one silicon precursor having one Si-C-Si bond selected from the group consisting of 1,1,1,3,3,3-hexachloro-1,3-disilapropane, 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 and 1,1,1,3,3,3-hexachloro-2-ethyl-1,3-disilapropane;

[0080] d. purging with an inert gas to remove any unreacted silicon precursor and forming a composition comprising a purge gas and a silicon precursor;

[0081] e. providing a plasma including ammonia source into the reactor to react with the surface to form silicon nitride or carbon-doped silicon nitride film;

[0082] f. purging with an inert gas to remove any reaction by-products;

[0083] g. Repeat steps c to f to provide a silicon nitride or carbon-doped silicon nitride film of the desired thickness;

[0084] h. Optionally, post-deposition treatment of the silicon nitride or carbon-doped silicon nitride film with thermal annealing or spike annealing at a temperature of 400 to 1000° C. or a UV light source, wherein the UV exposure step can be performed during film deposition or when deposition is completed;

[0085] i. Optionally, the silicon nitride or carbon-doped silicon nitride film is exposed to a plasma containing hydrogen or an inert gas or nitrogen after deposition to improve at least one physical property of the film.

[0086] In 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.% or less is deposited using a plasma enhanced ALD process. In this embodiment, the method comprises:

[0087] a. placing one or more substrates including surface features into a reactor;

[0088] b. 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;

[0089] c. Introducing into the reactor at least one silicon precursor having one Si-C-Si bond or two Si-C-Si bonds, which is selected from 1,1,1,3,3,3-hexachloro-1,3-disilapropane, 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, 1,1,1,3,3,3-hexachloro-2-ethyl-1,3-disilapropane, 1-chloro-1, 3-Disilacyclobutane, 1-bromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-1,3-disilacyclobutane, 1,3-dibromo-1,3-disilacyclobutane, 1,1,3-trichloro-1,3-disilacyclobutane, 1,1,3-tribromo-1,3-disilacyclobutane, 1,1,3,3-tetrachloro-1,3-disilacyclobutane, 1,1,3,3-tetrabromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane 1,3-Dibromo-1,3-dimethyl-1,3-disilacyclobutane, 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane, 1,1,3,3,5,5-hexachloro-1,5-dimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-hexachloro-3,3-dimethyl-1,3,5-trisilapentane, 1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-hexachloro-1,3,5-trisilapentane, 1,1,5,5-tetrachloro-1,3,5-trisilapentane, 1-iodo-1,3-disilacyclobutane, 1,1-diiodo-1,3-disilacyclobutane, 1,3-diiodo-1,3-disilacyclobutane, 1,1,3-triiodo-1,3-disilacyclobutane, 1,1,3,3-tetraiodo-1,3-disilacyclobutane, and 1,3-diiodo-1,3-dimethyl-1,3-disilacyclobutane;

[0090] d. purging with an inert gas to remove any unreacted silicon precursor and forming a composition comprising a purge gas and a silicon precursor;

[0091] e. providing a plasma including ammonia source into the reactor to react with the surface to form silicon nitride or carbon-doped silicon nitride film;

[0092] f. purging with an inert gas to remove any reaction by-products;

[0093] g. Repeat steps c to f to provide a silicon nitride or carbon-doped silicon nitride film of desired thickness.

[0094] In another embodiment of the method described herein, a silicon nitride or carbon-doped silicon nitride film having a carbon content of 5 at.% or less is deposited using a plasma enhanced ALD process. In this embodiment, the method comprises:

[0095] a. placing one or more substrates including surface features into a reactor (eg, into a conventional ALD reactor);

[0096] b. 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;

[0097] c. Introducing into the reactor at least one silicon precursor having two Si-C-Si bonds, which is selected from 1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-1,3-disilacyclobutane, 1,3-dibromo-1,3-disilacyclobutane, 1,1,3-trichloro-1,3-disilacyclobutane, 1,1,3-tribromo-1,3- Disilacyclobutane, 1,1,3,3-tetrachloro-1,3-disilacyclobutane, 1,1,3,3-tetrabromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane, 1,3-dibromo-1,3-dimethyl-1,3-disilacyclobutane, 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane, 1, 1,3,3,5,5-Hexachloro-1,5-dimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-Hexachloro-3,3-dimethyl-1,3,5-trisilapentane, 1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-Hexachloro-1,3,5-trisilapentane, 1,1,5, 5-tetrachloro-1,3,5-trisilapentane, 1-iodo-1,3-disilacyclobutane, 1,1-diiodo-1,3-disilacyclobutane, 1,3-diiodo-1,3-disilacyclobutane, 1,1,3-triiodo-1,3-disilacyclobutane, 1,1,3,3-tetraiodo-1,3-disilacyclobutane, and 1,3-diiodo-1,3-dimethyl-1,3-disilacyclobutane;

[0098] d. Purge with inert gas;

[0099] e. providing a plasma including ammonia source into the reactor to react with the surface to form silicon nitride or carbon-doped silicon nitride film;

[0100] f. purging with an inert gas to remove reaction by-products;

[0101] g. Repeat steps c to f to provide a silicon nitride or carbon-doped silicon nitride film of the desired thickness;

[0102] h. 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; wherein the UV exposure step may be performed during film deposition, or when deposition is completed;

[0103] i. Optionally, the silicon nitride or carbon-doped silicon nitride film is exposed to a plasma containing hydrogen or an inert gas or nitrogen after deposition to improve at least one physical property of the film.

[0104] In another embodiment of the method described herein, a carbon-doped silicon oxynitride film having a carbon content of 5 at.% or less is deposited using a plasma enhanced ALD process. In this embodiment, the method comprises:

[0105] a. placing one or more substrates including surface features into a reactor (eg, into a conventional ALD reactor);

[0106] b. 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;

[0107] c. Introducing into the reactor at least one silicon precursor having two Si-C-Si bonds, which is selected from 1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-1,3-disilacyclobutane, 1,3-dibromo-1,3-disilacyclobutane, 1,1,3-trichloro-1,3-disilacyclobutane, 1,1,3-tribromo-1,3- Disilacyclobutane, 1,1,3,3-tetrachloro-1,3-disilacyclobutane, 1,1,3,3-tetrabromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane, 1,3-dibromo-1,3-dimethyl-1,3-disilacyclobutane, 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane, 1, 1,3,3,5,5-Hexachloro-1,5-dimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-Hexachloro-3,3-dimethyl-1,3,5-trisilapentane, 1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-Hexachloro-1,3,5-trisilapentane, 1,1,5, 5-tetrachloro-1,3,5-trisilapentane, 1-iodo-1,3-disilacyclobutane, 1,1-diiodo-1,3-disilacyclobutane, 1,3-diiodo-1,3-disilacyclobutane, 1,1,3-triiodo-1,3-disilacyclobutane, 1,1,3,3-tetraiodo-1,3-disilacyclobutane, and 1,3-diiodo-1,3-dimethyl-1,3-disilacyclobutane;

[0108] d. Purge with inert gas;

[0109] e. providing a plasma including ammonia source into the reactor to react with the surface to form silicon nitride or carbon-doped silicon nitride film;

[0110] f. purging with an inert gas to remove reaction by-products;

[0111] g. Repeat steps c to f to provide a silicon nitride or carbon-doped silicon nitride film of the desired thickness;

[0112] h. post-deposition treating 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 silicon oxynitride or carbon-doped silicon oxynitride film in situ or in another chamber.

[0113] 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:

[0114] a. placing one or more substrates including surface features into a reactor;

[0115] b. 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;

[0116] c. introducing into the reactor at least one silicon precursor having one Si-C-Si bond selected from the group consisting of 1,1,1,3,3,3-hexachloro-1,3-disilapropane, 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 and 1,1,1,3,3,3-hexachloro-2-ethyl-1,3-disilapropane;

[0117] d. purging with an inert gas to remove any unreacted silicon precursor and forming a composition comprising a purge gas and a silicon precursor;

[0118] e. providing a first plasma including / comprising an ammonia source into the reactor to react with the surface to form silicon nitride or a carbon-doped silicon nitride film;

[0119] f. purging with an inert gas to remove any reaction by-products;

[0120] g. providing a second plasma comprising a nitrogen source into the reactor to react with the surface to form silicon nitride or a carbon-doped silicon nitride film;

[0121] h. purging with an inert gas to remove any reaction by-products; and

[0122] i. Repeat steps c to h to provide a silicon nitride or carbon-doped silicon nitride film of desired thickness.

[0123] 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:

[0124] a. placing one or more substrates including surface features into a reactor;

[0125] b. 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;

[0126] c. Introducing into the reactor at least one silicon precursor having two Si-C-Si bonds, which is selected from 1-chloro-1,3-disilacyclobutane, 1-bromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-1,3-disilacyclobutane, 1,3-dibromo-1,3-disilacyclobutane, 1,1,3-trichloro-1,3-disilacyclobutane, 1,1,3-tribromo-1,3- Disilacyclobutane, 1,1,3,3-tetrachloro-1,3-disilacyclobutane, 1,1,3,3-tetrabromo-1,3-disilacyclobutane, 1,3-dichloro-1,3-dimethyl-1,3-disilacyclobutane, 1,3-dibromo-1,3-dimethyl-1,3-disilacyclobutane, 1,1,1,3,3,5,5,5-octachloro-1,3,5-trisilapentane, 1, 1,3,3,5,5-Hexachloro-1,5-dimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-Hexachloro-3,3-dimethyl-1,3,5-trisilapentane, 1,1,3,5,5-pentachloro-1,3,5-trimethyl-1,3,5-trisilapentane, 1,1,1,5,5,5-Hexachloro-1,3,5-trisilapentane, 1,1,5, 5-tetrachloro-1,3,5-trisilapentane, 1-iodo-1,3-disilacyclobutane, 1,1-diiodo-1,3-disilacyclobutane, 1,3-diiodo-1,3-disilacyclobutane, 1,1,3-triiodo-1,3-disilacyclobutane, 1,1,3,3-tetraiodo-1,3-disilacyclobutane, and 1,3-diiodo-1,3-dimethyl-1,3-disilacyclobutane;

[0127] d. purging with an inert gas to remove any unreacted silicon precursor and forming a composition comprising a purge gas and a silicon precursor;

[0128] e. providing a first plasma comprising a nitrogen source into the reactor to react with the surface to form silicon nitride or a carbon-doped silicon nitride film;

[0129] f. purging with an inert gas to remove any reaction by-products;

[0130] g. providing a second plasma comprising ammonia source to the reactor to react with the surface to form silicon nitride or carbon-doped silicon nitride film;

[0131] h. purging with an inert gas to remove any reaction by-products; and

[0132] i. Repeat steps c to h to provide a silicon nitride or carbon-doped silicon nitride film of desired thickness.

[0133] In one embodiment, the substrate includes at least one feature, wherein the feature includes a patterned trench having an aspect ratio of 1:9 or greater and an opening of 180 nm or less.

[0134] In certain embodiments, the temperature of the reactor in the introducing step is one or more temperatures ranging from about room temperature (e.g., 20° C.) to about 600° C. Alternative ranges of substrate temperature have one or more of the following endpoints: 20, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, and 500° C. Exemplary temperature ranges include the following: 20 to 300° C., 100 to 300° C., or 100 to 350° C.

[0135] In yet another embodiment, the container for depositing the 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 as disclosed in U.S. Patent Nos. US7334595; US6077356; US5069244; and US5465766 (the disclosures of which are incorporated herein by reference). The container may include glass (borosilicate or quartz glass) or 316, 316L, 304 or 304L type stainless steel alloy (UNS designations S31600, S31603, S30400 S30403), which is equipped with appropriate valves and fittings to allow one or more precursors to be delivered to a reactor for a CVD or ALD process. 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% by weight 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+ , Fe 2+ , Fe3+ 、Ni 2+ Cr 3+ ions. As used herein, the term "substantially free" refers to Al 3+ , Fe 2+ , Fe 3+ 、Ni 2 + Cr 3+ ions refers to less than about 5ppm (by weight), preferably less than about 3ppm, more preferably less than about 1ppm, most preferably about 0.1ppm. The term "substantially free" refers to less than 5ppm (by weight) when it comes to Al, Fe, Ni, Cr, preferably less than 3ppm, more preferably less than 1ppm, most preferably 0.1ppm, as measured by ICP-MS. In certain embodiments, if necessary, such containers may also have a device for mixing the precursor with one or more other precursors. In these or other embodiments, the contents of the container may be premixed with other precursors. Alternatively, the silicon precursor and / or other precursors may be kept in a separate container or in a single container with a separator for keeping the silicon precursor and other precursors separated during storage.

[0136] The silicon-containing film is deposited on at least one surface of a substrate such as a semiconductor substrate. In the methods described herein, the substrate can be composed of and / or coated with various materials known in the art, including silicon films, such as crystalline silicon or amorphous silicon, silicon oxide, silicon nitride, amorphous carbon, silicon oxide, silicon nitride, 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 metals or metalloids such as GaAs, InP, GaP and GaN, and combinations thereof. These coatings can completely coat the semiconductor substrate, can be 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 has been exposed and developed with a pattern to partially coat the substrate. In certain embodiments, the semiconductor substrate comprises at least one surface feature selected from a hole, a through hole, a groove and a combination thereof. Potential applications of silicon-containing films include, but are not limited to, low-k spacers for FinFETs or nanosheets, sacrificial hard masks for self-aligned patterning processes (e.g., SADP, SAQP, or SAOP).

[0137] 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 material film onto a substrate of different compositions. Although the precursors, reagents, and sources used herein are sometimes described as "gaseous", it should be understood that the precursor can be a liquid or solid, which is transported to a reactor by direct evaporation, bubbling, or sublimation with or without an inert gas. In some cases, the vaporized precursor can be passed through a plasma generator.

[0138] In one embodiment, the silicon-containing film is deposited using an ALD process. In another embodiment, the silicon-containing film is deposited using a cyclic CVD (CCVD) process. In a further 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.

[0139] In certain embodiments, the method disclosed herein avoids the pre-reaction of the precursor by using ALD or cyclic CVD methods, and the ALD or cyclic CVD methods separate the precursors before and / or during the introduction into the reactor. In this regard, a deposition technique such as ALD or CCVD process is used to deposit a silicon-containing film. In one embodiment, the film is deposited by exposing the substrate surface alternately to one or more silicon-containing precursors, oxygen sources, nitrogen-containing sources or other precursors or reagents in a typical single-wafer ALD reactor, a semi-batch ALD reactor or a batch furnace ALD reactor by an ALD process. Film growth is carried out by self-limiting control of surface reactions, pulse length of each precursor or reagent, and deposition temperature. However, once the substrate surface is saturated, film growth 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 parts of the reactor, and each part is separated by an inert gas curtain, i.e., a space ALD reactor or a roll-to-roll ALD reactor.

[0140] Depending on the deposition method, in certain embodiments, the silicon precursors described herein and optionally other silicon-containing precursors can be introduced into the reactor at a predetermined molar volume or from about 0.1 to about 1000 micromoles. In this or other embodiments, the precursors can be introduced into the reactor for a predetermined time period. In certain embodiments, the time period is from about 0.001 to about 500 seconds.

[0141] In certain embodiments, the silicon nitride or carbon-doped silicon film deposited using the methods described herein is treated with an oxygen source, a reagent or precursor (i.e., water vapor) containing oxygen to be converted into carbon-doped nitrogen oxides. The oxygen source can be introduced into the reactor in the form of at least one oxygen source and / or can be incidentally present in other precursors used in 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, oxygenated water, air, a composition comprising water and other organic liquids), oxygen (O2), oxygen plasma, ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), nitrous oxide (N2O), carbon monoxide (CO), hydrogen peroxide (H2O2), plasma comprising water, 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 of about 1 to about 10,000 square cubic centimeters (sccm) or about 1 to about 1000 sccm. The oxygen source may be introduced for a time ranging from about 0.1 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.

[0142] 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, while the water pulse duration may have a pulse duration less than 0.01 seconds.

[0143] 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 range from 0.01 seconds to 100 seconds.

[0144] 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 and / or can be incidentally present in other precursors used in the deposition process.

[0145] 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.

[0146] In certain embodiments, the nitrogen source is introduced into the reactor at a flow rate ranging from about 1 to about 10,000 square cubic centimeters (sccm) or from about 1 to about 1000 sccm. The nitrogen-containing source may be introduced for a time period of about 0.1 to about 100 seconds. In embodiments where the film is deposited by an ALD or cyclic CVD process using a nitrogen and oxygen source, 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 a purge in between.

[0147] Deposition method disclosed herein includes one or more steps of purging unwanted or unreacted materials from the 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 the 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 for about 0.1 to 1000 seconds at a flow rate ranging from about 10 to about 10000sccm, thereby purging unreacted substances and any byproducts that may remain in the reactor.

[0148] 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 at which they are supplied to change the stoichiometric composition of the resulting film.

[0149] Energy is applied to at least one of the precursor, ammonia source, reducing agent such as hydrogen plasma, other precursors or a combination thereof to induce 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.

[0150] In certain embodiments, a secondary RF source may be used to change the plasma characteristics at the substrate surface. In embodiments where 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 external to the reactor and supplied to the reactor.

[0151] 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 used. In an alternative embodiment, a combined liquid delivery and flash process unit, such as a turbo evaporator manufactured by MSP Corporation of Shoreview, MN, can be used to enable quantitative delivery of low-volatility materials, which results in reproducible delivery and deposition without thermal decomposition of the precursor. In a liquid delivery configuration, the precursors described herein can be delivered in pure liquid form, or 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 suitable properties, such as may be desirable and advantageous in a given end-use application to form a film on a substrate.

[0152] 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 in any combination thereof. The respective steps of supplying the precursor and nitrogen-containing source gas can be performed by varying the duration of supplying them to vary the stoichiometric composition of the resulting silicon-containing film.

[0153] 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 in 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. Films deposited with the silicon precursors described herein having one or two Si-C-Si bonds have improved properties, such as, but not limited to, wet etch rate (which is lower than the wet etch rate of the film before the treatment step) or density (which is higher than the density before the treatment step) when compared to films deposited with previously disclosed silicon precursors under the same conditions. In a specific embodiment, the film so deposited is treated intermittently during the deposition process. These intermittent or intermediate 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.

[0154] In embodiments where the film is treated with a high temperature annealing step, the annealing temperature is at least 100° C. or above the deposition temperature. In this or other embodiments, the annealing temperature ranges from about 400° C. to about 1000° C. In this or other embodiments, the annealing treatment 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).

[0155] In the embodiment where the film is UV treated, the film is exposed to a broadband UV, or alternatively, a UV source having a wavelength range of 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.

[0156] 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 contaminants from penetrating the film during subsequent plasma treatment. The passivation layer can be deposited using atomic layer deposition or cyclic chemical vapor deposition.

[0157] 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 film dielectric constant and improves damage resistance to subsequent plasma ashing processes while still keeping the carbon content in the bulk almost unchanged.

[0158] The following examples illustrate certain aspects of the invention and are not intended to limit the scope of the appended claims.

[0159] Example

[0160] In the following examples, unless otherwise stated, properties were 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 with a showerhead design with 13.56 MHz direct plasma.

[0161] In typical process conditions, unless otherwise stated, the chamber pressure is fixed at a pressure of about 1 to about 5 Torr. Additional inert gas is used to maintain the chamber pressure.

[0162] Film deposition included the steps listed in Tables 3 and 4 for thermal ALD and plasma enhanced ALD ("PEALD"). Steps a to d in Table 3 constituted one PEALD cycle and were repeated. Steps a to f in Tables 4 or 5 constituted one PEALD cycle and were repeated. Unless otherwise stated, a total of 100 or 200 or 300 or 500 times were repeated to obtain the desired film thickness.

[0163] Table 3. Deposition steps of ALD silicon nitride films

[0164]

[0165]

[0166] Table 4. Deposition steps of ALD silicon nitride films

[0167]

[0168] Table 5: Deposition steps of ALD silicon nitride film

[0169]

[0170]

[0171] The refractive index (RI) and thickness of the deposited films were measured using an ellipsometer. The film inhomogeneity was calculated using the standard equation: % inhomogeneity = ((maximum thickness - minimum thickness) / (2*average (avg) thickness)). The film structure and composition were analyzed using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The density of the film was measured using X-ray reflectometry (XRR).

[0172] Example 1: ALD Silicon Nitride Using 1,1,3,3-Tetrachloro-1,3-Disilacyclobutane and NH3 / Argon Plasma

[0173] The silicon wafer was loaded into a CN-1 reactor equipped with a showerhead design with a 13.56 MHz direct plasma and heated to 300° C. at a chamber pressure of 1 Torr. 1,1,3,3-Tetrachloro-1,3-disilacyclobutane as a silicon precursor was delivered as a vapor into the reactor using bubbling or vapor pumping.

[0174] The ALD cycle consisted of the process steps provided in Table 3 except steps e and f; and the following process parameters were used:

[0175] a. Introduce the vapor of 1,1,3,3-tetrachloro-1,3-disilacyclobutane into the reactor

[0176] Argon flow: 100 sccm through the precursor container

[0177] Pulse: 2 seconds

[0178] Ar flow: 1000sccm

[0179] b.Purge

[0180] Argon flow: 1000sccm

[0181] Purge time: 10 seconds

[0182] c. Introducing ammonia plasma

[0183] Argon flow: 1000sccm

[0184] Ammonia flow: 100 sccm

[0185] Plasma power: 300W

[0186] Pulse: 10 seconds

[0187] d.Purge

[0188] Argon flow: 1000sccm

[0189] Purge time: 5 seconds

[0190] Steps a to d were repeated for 250 cycles to provide 30 nm of silicon nitride with a composition of 58.0 at.% nitrogen, 39.7 at.% silicon, 2.3 at.% oxygen, and 0.12 at.% chlorine. Carbon was undetectable. The refractive index (RI) was about 1.90. The silicon nitride thus deposited did not change when exposed to ambient air for more than 24 hours, indicating that it was a stable film.

[0191] Example 2: ALD Silicon Nitride Using 1,1,3,3-Tetrachloro-1,3-Disilacyclobutane and NH3 / Argon Plasma

[0192] The silicon wafer was loaded into a CN-1 reactor equipped with a showerhead design with a 13.56 MHz direct plasma and heated to 300°C at a chamber pressure of 1 Torr. 1,1,3,3-Tetrachloro-1,3-disilacyclobutane was delivered as a vapor into the reactor using bubbling. The ALD cycle consisted of the process steps provided in Table 3 except steps e and f; and the following process parameters were used:

[0193] a. Introduce the vapor of 1,1,3,3-tetrachloro-1,3-disilacyclobutane into the reactor

[0194] Argon flow: 100 sccm through the precursor container

[0195] Pulse: 2 seconds

[0196] Argon: 1000sccm

[0197] b. Inert gas purge

[0198] Argon flow: 1000sccm

[0199] Purge time: 10 seconds

[0200] c. Introducing ammonia plasma

[0201] Argon flow: 1000sccm

[0202] Ammonia flow: 25sccm

[0203] Plasma power: 300W

[0204] Pulse: 10 seconds

[0205] d.Purge

[0206] Argon flow: 1000sccm

[0207] Purge time: 5 seconds

[0208] Steps a to d were repeated for 250 cycles to provide 30 nm silicon nitride with a composition of 58.0 at.% nitrogen, 39.6 at.% silicon, 2.2 at.% oxygen and 0.27 at.% chlorine. Carbon was not detectable. The refractive index (RI) was about 1.90.

[0209] Example 3: ALD Silicon Nitride Using 1,1,3,3-Tetrachloro-1,3-Disilacyclobutane, NH3 / Ar Plasma and Nitrogen / Ar Plasma

[0210] The silicon wafer was loaded into a CN-1 reactor equipped with a showerhead design with a 13.56 MHz direct plasma and heated to 300 °C at a chamber pressure of 1 Torr. 1,1,3,3-Tetrachloro-1,3-disilacyclobutane was delivered as a vapor into the reactor using bubbling. The ALD cycle consisted of the process steps provided in Table 4 and used the following process parameters:

[0211] a. Introduce the vapor of 1,1,3,3-tetrachloro-1,3-disilacyclobutane into the reactor

[0212] Argon flow: 100 sccm through the precursor container

[0213] Pulse: 2 seconds

[0214] Argon: 1000sccm

[0215] b. Inert gas purge

[0216] Argon flow: 1000sccm

[0217] Purge time: 20 seconds

[0218] c. Introducing ammonia plasma

[0219] Argon flow: 1000sccm

[0220] Ammonia flow: 50sccm

[0221] Plasma power: 100W

[0222] Pulse: 10 seconds

[0223] d.Purge

[0224] Argon flow: 1000sccm

[0225] Purge time: 5 seconds

[0226] e. Introducing nitrogen plasma

[0227] Argon flow: 1000sccm

[0228] Nitrogen flow: 500sccm

[0229] Plasma power: 100W

[0230] Pulse: 5 seconds

[0231] f.Purge

[0232] Argon flow: 1000sccm

[0233] Purge time: 5 seconds

[0234] Steps a to f were repeated for 400 cycles to provide 24 nm of silicon nitride with a composition of 40.76 at.% nitrogen, 37.04 at.% silicon, 0.23 at.% oxygen and 0.17 at.% chlorine, 0.28 at.% carbon. Density 2.73 g / cm 3 The refractive index (RI) is about 1.90.

[0235] Example 4: ALD Silicon Nitride Using 1,1,3,3-Tetrachloro-1,3-Disilacyclobutane, Nitrogen / Ar Plasma and NH3 / Argon Plasma

[0236] The silicon wafer was loaded into a CN-1 reactor equipped with a showerhead design with a 13.56 MHz direct plasma and heated to 300 °C at a chamber pressure of 1 Torr. 1,1,3,3-Tetrachloro-1,3-disilacyclobutane was delivered as a vapor into the reactor using bubbling. The ALD cycle consisted of the process steps provided in Table 5 and used the following process parameters:

[0237] a. Introduce the vapor of 1,1,3,3-tetrachloro-1,3-disilacyclobutane into the reactor

[0238] Argon flow: 100 sccm through the precursor container

[0239] Pulse: 2 seconds

[0240] Argon: 1000sccm

[0241] b. Inert gas purge

[0242] Argon flow: 1000sccm

[0243] Purge time: 30 seconds

[0244] c. Introducing nitrogen plasma

[0245] Argon flow: 1000sccm

[0246] Nitrogen flow: 500sccm

[0247] Plasma power: 100W

[0248] Pulse: 5 seconds

[0249] d.Purge

[0250] Argon flow: 1000sccm

[0251] Purge time: 5 seconds

[0252] e. Introducing ammonia plasma

[0253] Argon flow: 1000sccm

[0254] Ammonia flow: 50sccm

[0255] Plasma power: 100W

[0256] Pulse: 10 seconds

[0257] f.Purge

[0258] Argon flow: 1000sccm

[0259] Purge time: 5 seconds

[0260] Steps a to f are repeated for 400 cycles to provide 40 nm of silicon nitride with a composition of 58.78 at.% nitrogen, 38.30 at.% silicon, 2.43 at.% oxygen and 0.50 at.% chlorine, 0.28 at.% carbon, and a density of 2.75 g / cm 3 The refractive index (RI) is about 1.90.

[0261] Although illustrated and described above with reference to certain specific embodiments and working examples, the present invention is not intended to be limited to the details shown. Rather, various modifications may be made to the details within the scope and range of equivalents of the claims without departing from the spirit of the present invention. For example, it is expressly intended that all ranges broadly recited herein include within their scope all narrower ranges falling within such broader ranges.

Claims

1. A method for forming a film containing silicon and nitrogen by a plasma enhanced ALD process, the method comprising: a) providing a substrate comprising surface features in a reactor; b) heating the reactor to one or more temperatures in the range of up to 600° C. and optionally maintaining the reactor at a pressure of 100 Torr or less; c) introducing at least one silicon precursor into the reactor to form a silicon-containing material on the substrate, the silicon precursor being selected from: d) purging the reactor of any unreacted silicon precursor and / or any reaction byproducts from step c using a first inert gas; e) providing a plasma containing an ammonia source into the reactor to react with the silicon-containing substance to form a silicon nitride film; f) purging the reactor of any further reaction by-products from step e with a second inert gas; and g) repeating steps c to f as needed to make the silicon nitride film reach a predetermined thickness; wherein the film has a dielectric constant (k) of 7 or less, an oxygen content of 5 at. % or less, and a carbon content of 3 at. % or less, as measured by X-ray photoelectron spectroscopy. 2 . The method according to claim 1 , wherein the silicon nitride film is a carbon-doped silicon nitride film.

3. The method according to claim 1 or 2, further comprising: The silicon nitride film is treated with a spike anneal at a temperature ranging from 400 to 1000°C.

4. The method according to claim 1 or 2, further comprising: The silicon nitride film is exposed to a UV light source during or after deposition of the silicon nitride film.

5. The method according to claim 1 or 2, further comprising: The silicon nitride film is exposed to a plasma containing hydrogen or an inert gas or nitrogen.

6. The method according to claim 1 or 2, further comprising: The silicon nitride film is treated with an oxygen source 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.

7. The method of claim 6, wherein the silicon nitride film is a carbon-doped silicon nitride film, and wherein the step of treating with an oxygen source converts the carbon-doped silicon nitride into a carbon-doped silicon oxynitride film.

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

9. The method of claim 2, further comprising thermally annealing the carbon-doped silicon nitride film at a temperature of 300°C to 1000°C.

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

11. The method according to claim 1 or 2, further comprising: h) providing a plasma containing a nitrogen source into the reactor to react with the silicon-containing substance and further form the silicon nitride film; and i) purging the reactor of any further reaction by-products with a second inert gas, Step g) wherein steps c to f are repeated further comprises repeating steps h and i, such that steps c to i are repeated to allow the silicon nitride film to reach a predetermined thickness.

12. A film formed according to the method of any one of claims 1 to 11, having a dielectric constant (k) of 7 or less, an oxygen content of 5 at.% or less, and a carbon content of 3 at.% or less, as measured by X-ray photoelectron spectroscopy.

13. The film of claim 12 having a carbon content of 2 atomic weight % or less as measured by X-ray photoelectron spectroscopy.

14. The film of claim 13 having a carbon content of 1 atomic weight % or less as measured by X-ray photoelectron spectroscopy.

15. The film according to claim 12, having a dielectric constant (k) of 7 or less, an oxygen content of 5 at.% or less, a carbon content of 3 at.% or less, and a density of 2.7 g / cm 3 or higher.

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