Compositions and Methods for Depositing Silicon-Containing Films

Abstract

Compositions and methods for forming a dielectric film comprising silicon and carbon on at least one surface of a substrate are described, the method comprising introducing at least one silacycloalkane precursor selected from compounds represented by Formula IA and compounds represented by Formula IB as defined herein into the reactor: #imgabs0#

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of September 11, 2018, an application number of 201880071503.4, and an invention title of "Compositions and Methods for Depositing Silicon-Containing Films".

[0002] Cross - reference to related applications

[0003] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62 / 558,621, filed on September 14, 2017, the entire content of which is incorporated herein by reference. Technical Field

[0004] Described herein are methods and compositions for depositing conformal, stoichiometric, or non-stoichiometric silicon carbide or silicon carbonitride films using a silicon precursor comprising at least one silacycloalkane. More specifically, described herein are deposition processes for depositing dielectric films using silacycloalkane precursors and compositions comprising such precursors, such as, but not limited to, plasma-enhanced atomic layer deposition ("PEALD"), plasma-enhanced cyclic chemical vapor deposition ("PECCVD"), and plasma-enhanced flowable vapor deposition ("PEFCVD"). Background Art

[0005] Low-pressure chemical vapor deposition (LPCVD) processes are among the more widely accepted methods in the semiconductor industry for depositing silicon nitride films. Low-pressure chemical vapor deposition (LPCVD) using ammonia may require deposition temperatures above 650 °C to obtain reasonable growth rates and uniformity. Higher deposition temperatures are typically employed to provide improved film properties. One of the more common industrial methods for growing silicon nitride is by low-pressure chemical vapor deposition in a hot-wall reactor at temperatures above 750 °C using silane, dichlorosilane, and / or ammonia as precursors. However, there are several disadvantages to using this method. For example, certain precursors, such as silane, are pyrophoric. This can pose problems in handling and use. Also, films deposited from dichlorosilane may contain certain impurities, such as chlorine and ammonium chloride, which are formed as by-products during the deposition process.

[0006] U.S. Patent No. 9,455,138 discloses a method for forming a dielectric film in trenches on a substrate by plasma-enhanced atomic layer deposition (PEALD) for ≥ 1 process cycle,

[0007] Each process cycle includes (i) pulse-feeding a silicon precursor, (ii) supplying a hydrogen-containing reactant gas at a flow rate of 30 - 800 sccm in the absence of a nitrogen-containing gas, (iii) supplying a noble gas to the reaction space, and (iv) applying RF power in the presence of the reactant gas and the noble gas and in the absence of any precursor in the reaction space to form a single layer constituting a dielectric film on the substrate at a growth rate of less than 1 atomic layer thickness / cycle.

[0008] WO2012 / 039833A discloses a method for forming silicon carbide on a substrate. An atomic layer deposition method for forming silicon carbide is described, in which a first reactant gas of the formula Si n H a X b , where n = 1 - 5, a + b = 2n + 2, and X = F, Cl, Br, I; and a second reactant gas of the formula MR 3-b Y b , where R is a hydrocarbon-containing substituent, Y is a halide, hydride, or other ligand and b = 1 - 3 are successively deposited on the substrate, and then exposed to a plasma. This process can be repeated multiple times to deposit multiple silicon carbide layers.

[0009] U.S. Patent No. 9,234,276 discloses a method and system for providing a SiC film. A SiC layer can be provided under process conditions using one or more silicon precursors having ≥1 Si - H bond and / or Si - Si bond. The silicon precursor can also have ≥1 Si - O bond and / or Si - C bond. One or more radical species in a substantially low energy state can react with the silicon precursor

[0010] to form a SiC film. The ≥1 radical species can be formed in a remote plasma source. U.S. Patent No. 8,846,536 discloses a method for depositing and modifying a flowable dielectric film.

[0011] Through one or more integrated processes, the wet etching rate of the flowable dielectric film can be changed by at least 10 times.

[0012]

[0013] Auner, N. and Grobe, J. (1980). "Silaethenes. II. Preparation and characterization of 1,3 - disilacyclobutanes." J. Organomet. Chem. 188(2): 5 151 - 177 discloses 3 - disilacyclobutane I (R, R1 = Cl, Me, Me2N, CH2:CH, Ph) (a) by reacting from chloromethylchlorosilane RR 1 ​The ring synthesis of Si(CH2Cl)Cl, (b) by pyrolysis of monosilacyclobutane II; and (c) by substituting chlorine with an alkyl group in the SiCl-containing 1,3-disilacyclobutane obtained by the procedure of step (a) or (b). These synthetic methods were compared.

[0014] U.S. Publication No. 2013 / 0217241 discloses the deposition and treatment of a flowable layer containing Si-C-N. Si and C can be from a Si-C-containing precursor, and N can be from an N-containing precursor. The initial flowable layer containing Si-C-N is treated to remove the components that achieve flowability. Removing these components can improve etch tolerance, reduce shrinkage, and adjust film tension and electrical properties. The post-treatment can be thermal annealing, UV exposure, or high-density plasma.

[0015] U.S. Patent No. 8,889,566 discloses a method for depositing a flowable film by locally exciting a silicon precursor with a plasma and depositing with a second plasma. The silicon precursor can be a silylamine, a higher silane, or a halosilane. The second reactant gas can be NH3, N2, H2, and / or O2.

[0016] U.S. Patent No. 7,825,040 discloses a method for filling gaps by introducing an alkoxysilane or an aminosilane precursor and depositing a flowable silicon-containing film by plasma reaction. The precursor does not contain Si-C bonds or C-C bonds.

[0017] U.S. Patent Nos. 8,889,566, 7,521,378, and 8,575,040 describe methods for depositing a silicon oxide film using a flowable chemical vapor deposition process as gas-phase polymerization. Compounds such as trimethylsilylamine (TSA) are used to deposit oligomers containing Si, H, and N, which are then oxidized to SiO x film.

[0018] U.S. Patent No. 8,846,536 discloses a method for depositing and modifying a flowable dielectric film. By one or more integration processes, the wet etch rate of the flowable dielectric film can be changed by at least 10 times.

[0019] Accordingly, there is a need in the art to provide low-temperature (e.g., process temperatures of 400 °C or lower) methods for depositing conformal, high-quality silicon carbide or silicon carbonitride films, where the films have one or more of the following characteristics: a density of 2.2 grams per cubic centimeter (g / cc) or higher, a low wet etch rate (as measured in dilute hydrofluoric acid (HF)), and combinations thereof, compared to other silicon nitride films using other deposition methods or precursors.

[0020] The disclosures of the previously described patents, patent applications, and published publications are incorporated herein by reference. Summary of the Invention

[0021] The present disclosure describes methods for forming dielectric films comprising stoichiometric or non-stoichiometric silicon carbide, silicon carbonitride films, silicon oxycarbide, and silicon carbonitride oxide on at least a portion of a substrate.

[0022] In one aspect, the silicon precursors described herein include at least one silacycloalkane precursor selected from the compounds represented by the structure of Formula IA and the compounds represented by the structure of Formula IB:

[0023]

[0024] wherein R 1 is selected from hydrogen, straight-chain or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, straight-chain or branched C2 to C 10 alkenyl, and straight-chain or branched C2 to C 10 alkynyl; and R 2 is selected from straight-chain or branched C2 to C6 alkenyl, straight-chain or branched C2 to C6 alkynyl, and cyclic C3 to C 10 alkyl.

[0025] In another aspect, a composition is provided that comprises: (a) at least one silacycloalkane precursor selected from the compounds represented by the structure of Formula IA and the compounds represented by the structure of Formula IB:

[0026]

[0027] wherein R 1 is selected from hydrogen, straight-chain or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, straight-chain or branched C2 to C 10 alkenyl, and straight-chain or branched C2 to C 10 alkynyl; and R 2 is selected from straight-chain or branched C2 to C6 alkenyl, straight-chain or branched C2 to C6 alkynyl, and cyclic C3 to C 10 alkyl; and (b) a solvent. In certain embodiments of Formula I, R 1 and R 2 are each hydrogen. In other embodiments, R 1 is hydrogen. In certain embodiments of the compositions described herein, the solvent is at least one selected from ethers, tertiary amines, alkyl hydrocarbons, aromatic hydrocarbons, tertiary amino ethers, and combinations thereof. In certain embodiments, the difference between the boiling point of the silacycloalkane and the boiling point of the solvent is 40 °C or less.

[0028] In one aspect, a method for forming a silicon carbide film is provided, the method comprising the steps of:

[0029] a. Providing a substrate in a reactor;

[0030] b. Introduce at least one silacycloalkane precursor selected from the compound represented by the formula IA structure and the compound represented by the formula IB structure into the reactor:

[0031]

[0032] wherein R 1 is selected from hydrogen, straight-chain or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, straight-chain or branched C2 to C 10 alkenyl and straight-chain or branched C2 to C 10 alkynyl; and R 2 is selected from straight-chain or branched C2 to C6 alkenyl, straight-chain or branched C2 to C6 alkynyl and cyclic C3 to C 10 alkyl, wherein the at least one silacycloalkane precursor reacts on at least a part of the surface of the substrate to provide a chemisorbed layer;

[0033] c. Purge the reactor with a purge gas;

[0034] d. Introduce a plasma-containing source into the reactor to react with at least a part of the chemisorbed layer and provide at least one reactive site, wherein the plasma is generated at a power density of about 0.01 to about 1.5 W / cm 2 ; and

[0035] e. Optionally purge the reactor with an inert gas; and

[0036] wherein steps b to e are repeated until a silicon carbide film with a desired thickness is obtained.

[0037] In another aspect, there is provided a method for forming a dielectric film containing silicon and carbide using a deposition process selected from a plasma-enhanced atomic layer deposition process, a plasma-enhanced ALD-like process, or a plasma-enhanced flowing chemical vapor deposition, the method comprising the following steps:

[0038] a. Provide a substrate in a reactor;

[0039] b. Introduce at least one silacycloalkane precursor selected from the following into the reactor: 1,3-divinyl-1,3-disilacyclobutane, 1,3-divinyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetravinyl-1,3-disilacyclobutane, 1,3,5-trivinyl-1,3,5-trisilacyclohexane, 1,3,5-trivinyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexavinyl-1,3,5-trisilacyclohexane, 1,3-diallyl-1,3-disilacyclobutane, 1,3-diallyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraallyl-1,3-disilacyclobutane, 1,3,5-triallyl-1,3,5-trisilacyclohexane, 1,3,5-triallyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaallyl-1,3,5-trisilacyclohexane, 1,3-diethynyl-1,3-disilacyclobutane, 1,3-diethynyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraethynyl-1,3-disilacyclobutane, 1,3,5-triethynyl-1,3,5-trisilacyclohexane, 1,3,5-triethynyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaethynyl-1,3,5-trisilacyclohexane, 1,3-dicyclopropyl-1,3-disilacyclobutane, 1,3-dicyclopropyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetracyclopropyl-1,3-disilacyclobutane, and combinations thereof, wherein the at least one silacycloalkane precursor reacts on at least a portion of the surface of the substrate to provide a chemisorbed layer;

[0040] c. Purge the reactor with a purge gas comprising at least one selected from nitrogen, noble gases, and combinations thereof;

[0041] d. Introduce a plasma-containing source into the reactor to react with at least a portion of the chemisorbed layer and provide at least one reactive site, wherein the plasma is generated at a power density of about 0.01 to about 1.5 W / cm 2 ; and

[0042] e. Optionally purge the reactor with an inert gas; and

[0043] wherein steps b to e are repeated until a silicon carbide film of a desired thickness is obtained.

[0044] In another aspect, the present invention relates to a method for forming a dielectric film comprising silicon, nitrogen and carbon on at least one surface of a substrate using at least one deposition process selected from a plasma enhanced atomic layer deposition process, a plasma enhanced ALD-like process and a plasma enhanced flowable chemical vapor deposition, the method comprising the steps of:

[0045] a. Providing a substrate in a reactor;

[0046] b. Introducing at least one silacycloalkane precursor selected from the compounds represented by formula IA structure and the compounds represented by formula IB structure into the reactor:

[0047]

[0048] wherein R 1 is selected from hydrogen, straight-chain or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, straight-chain or branched C2 to C 10 alkenyl and straight-chain or branched C2 to C 10 alkynyl; and R 2 is selected from straight-chain or branched C2 to C6 alkenyl, straight-chain or branched C2 to C6 alkynyl and cyclic C3 to C 10 alkyl, wherein the at least one silacycloalkane precursor reacts on at least a portion of the surface of the substrate to provide a chemisorbed layer;

[0049] c. Purging the reactor with a purge gas comprising at least one selected from nitrogen, noble gases and combinations thereof;

[0050] d. Introducing a plasma comprising a nitrogen source into the reactor to react with at least a portion of the chemisorbed layer and provide at least one reactive site, wherein the plasma is generated at a power density of about 0.01 to about 1.5 W / cm 2 ; and

[0051] e. Optionally purging the reactor with an inert gas; and

[0052] wherein steps b to e are repeated until a silicon carbonitride film of a desired thickness is obtained.

[0053] A further aspect of the present invention relates to a silicon-containing film produced by any of the foregoing methods or from any of the foregoing compositions, wherein the silicon carbide or silicon carbonitride film has a density of 2.2 g / cc or higher.

[0054] The various aspects of the present invention can be used alone or in various combinations with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1is an SEM micrograph of a PEFCVD film deposited from the precursor 1,1,3,3 - tetravinyl - 1,3 - disilacyclobutane according to Example 4. Detailed Description

[0056] Depositing conformal, stoichiometric and non - stoichiometric silicon carbide or silicon carbonitride films at low temperatures (e.g., temperatures of 400 °C or lower) that meet one or more criteria considered to be high - quality films has been a long - standing industry challenge. There are various applications in the semiconductor field that require high - quality films, such as advanced patterning or spacers. A silicon carbide or silicon carbonitride film is considered a "high - quality" film if it has one or more of the following characteristics: a density of 2.2 grams per cubic centimeter (g / cc) or higher (e.g., from about 2.2 to about 3.0 g / cc, from about 2.4 to about 3.0 g / cc, and in some cases from about 2.5 to about 2.8 g / cc) compared to other silicon carbide or silicon carbonitride films, a low wet etch rate (as measured in dilute hydrofluoric acid (0.5 wt% HF in deionized water) according to the method described in more detail below), and combinations thereof. In these or other embodiments, the refractive index of the silicon nitride film as measured by ellipsometry should be 1.9 or higher (e.g., from about 1.9 to about 2.4, from about 2.0 to about 2.4, and in some cases from about 2.0 to about 2.2).

[0057] In one aspect, compositions for depositing silicon - containing films are described herein, wherein the compositions comprise: (a) at least one silacycloalkane precursor selected from the compounds represented by the formula IA structure and the compounds represented by the formula IB structure:

[0058]

[0059] wherein R 1 is selected from hydrogen, straight - chain or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, straight - chain or branched C2 to C 10 alkenyl and straight - chain or branched C2 to C 10 alkynyl; and R 2 is selected from straight - chain or branched C2 to C6 alkenyl, straight - chain or branched C2 to C6 alkynyl and cyclic C3 to C 10an alkyl group; and (b) optionally, at least one solvent. In certain embodiments of the compositions described herein, exemplary solvents include, but are not limited to, ethers, tertiary amines, alkyl hydrocarbons, aromatic hydrocarbons, tertiary amino ethers, and combinations thereof. In certain embodiments, the difference in boiling point between the silacycloalkane and the solvent is 40 °C or less. The weight percent of the silacycloalkane precursor compound in the solvent can vary between 1 and 99 wt%, or 10 and 90 wt%, or 20 and 80 wt%, or 30 and 70 wt%, or 40 and 60 wt%, or 50 and 50 wt%. In some embodiments, the composition can be delivered to a reaction chamber for a silicon-containing film by direct liquid injection.

[0060] In one embodiment, described herein is an atomic layer deposition (ALD) or ALD-like method using a silacycloalkane precursor of formula IA or IB described herein at one or more deposition temperatures in the range of low temperature or about 25 °C to about 400 °C in a plasma process comprising nitrogen and optionally a noble gas.

[0061] Described herein are methods for forming a stoichiometric or non-stoichiometric silicon carbide or silicon carbonitride film comprising silicon and nitrogen on at least a portion of a substrate. In certain embodiments, the silicon carbide or silicon carbonitride film further comprises oxygen, such as a silicon oxynitride film. In this or other embodiments, the silicon carbide film comprises oxygen and nitrogen, such as a silicon carbon oxynitride film having an oxygen content in the range of 0.1 to 30 atomic % and a carbon content in the range of 0.1 to 40 atomic % as measured by XPS.

[0062] Exemplary silacycloalkane precursors having the structure represented by formula IA or IB include, but are not limited to, the following precursors shown in Table 1.

[0063] Table 1. Precursors of formula IA or IB

[0064]

[0065]

[0066]

[0067] The silacycloalkane precursors having the structure represented by formula IA or IB described herein exhibit a balance of reactivity and stability, making them ideally suitable for use in semiconductor device manufacturing

[0068] PEALD, PECCVD, or PEFCVD precursors for the process. With respect to reactivity, some precursors may have too high a boiling point (e.g., above about 200 °C) to be vaporized and transported to the reactor for deposition as a film on a substrate. Precursors with relatively high boiling points require the delivery vessels and pipelines to be heated at or above the boiling point of the precursor under a given vacuum to prevent condensation or particle formation in the vessel, pipeline, or both. Importantly, the silacycloalkane precursors having the structure represented by Formula IA or IB preferably have at least two carbon-carbon double bonds or triple bonds or at least two cyclic alkyl groups, and are thus believed to be capable of depositing silicon carbide through crosslinking or polymerization of carbon-carbon double bonds or triple bonds or cyclic alkyl groups, especially cyclopropyl, under plasma conditions. In certain embodiments, the silacycloalkane precursors having the structure represented by Formula IA or IB herein contain 2 wt% or less, or 1 wt% or less, or 0.5 wt% or less of by-products (after storage for 6 months or longer, or one year or longer), indicating that it is storage stable. In certain embodiments, the silacycloalkane precursors having the structure represented by Formula IA or IB herein contain 100 ppm or less of impurities such as halides like chlorides, or 50 ppm or less of halide impurities, or 10 ppm or less of halide impurities. In addition to the foregoing advantages, in certain embodiments, for example, when depositing silicon carbide or silicon carbonitride films using PEALD, PECCVD, or PEFCVD deposition methods, the silacycloalkane precursors described herein may be capable of depositing high-density materials at one or more deposition temperatures, such as 400 °C or lower, 350 °C or lower, 300 °C or lower, or 250 °C or lower, 200 °C or lower, 150 °C or lower, 100 °C or lower, or 50 °C or lower.

[0069] Throughout the specification, the term "alkyl hydrocarbon" refers to straight-chain or branched C6 to C 20 hydrocarbons, cyclic C6 to C 20 hydrocarbons. Exemplary hydrocarbons include, but are not limited to, hexane, heptane, octane, nonane, decane, dodecane, cyclooctane, cyclononane, cyclodecane, and mixtures thereof.

[0070] Throughout the specification, the term "aromatic hydrocarbon" refers to C6 to C 20 aromatic hydrocarbons. Exemplary aromatic hydrocarbons include, but are not limited to, toluene and mesitylene.

[0071] In Formula IA or IB and throughout the specification, the term "cycloalkyl" represents a cyclic functional group having 3 to 10 or 4 to 10 or 5 to 10 carbon atoms. Exemplary cycloalkyls include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl, and preferably cyclopropyl due to its high reactivity.

[0072] In Formula IA or IB and throughout the specification, the term "aryl" refers to an aromatic cyclic functional group having 5 to 12 carbon atoms or 6 to 10 carbon atoms. Exemplary aryl groups include, but are not limited to, phenyl, benzyl, chlorobenzyl, tolyl, and o - xylyl.

[0073] In Formula IA or IB and throughout the specification, the term "alkyl" refers to a straight - chain or branched - chain functional group having 1 to 10 or 1 to 4 carbon atoms. Exemplary alkyl groups include, but are not limited to, methyl, ethyl, n - propyl, isopropyl, n - butyl, isobutyl, sec - butyl, tert - butyl, n - pentyl, isopentyl, tert - pentyl, hexyl, isohexyl, and neohexyl. In certain embodiments, the alkyl group may have one or more functional groups attached thereto, such as, but not limited to, alkoxy, dialkylamino, or a combination thereof. In other embodiments, the alkyl group does not have one or more functional groups attached thereto.

[0074] In Formula IA or IB and throughout the specification, the term "alkenyl" refers to a group having one or more carbon - carbon double bonds and having 2 to 10 or 2 to 6 or 2 to 4 carbon atoms. Exemplary alkenyl groups include, but are not limited to, vinyl (CH2═CH - ) or allyl (CH2═CHCH2 - ).

[0075] In Formula IA or IB and throughout the specification, the term "alkynyl" refers to a group having one or more carbon - carbon triple bonds and having 2 to 10 or 2 to 6 or 2 to 4 carbon atoms. Exemplary alkynyl groups include ethynyl.

[0076] Throughout the specification, as used herein, the term "organic amine" describes an organic compound having at least one nitrogen atom. Examples of organic amines include, but are not limited to, methylamine, ethylamine, propylamine, isopropylamine, tert - butylamine, sec - butylamine, tert - pentylamine, ethylenediamine, dimethylamine, trimethylamine, diethylamine, and triethylamine.

[0077] In certain embodiments, one or more of the alkyl, alkenyl, alkynyl, alkoxy, dialkylamino, aryl, and / or electron - withdrawing group in Formula IA or IB may be substituted or have one or more atoms or atomic groups replaced, for example, by a hydrogen atom. Exemplary substituents include, but are not limited to, oxygen, sulfur, halogen atoms (e.g., F, Cl, I, or Br), nitrogen, and phosphorus. Exemplary substituted substituents include, but are not limited to, straight - chain or branched C1 - C6 fluorinated alkyl groups. In one specific embodiment, R 1 to R 4 at least one of which is a straight - chain or branched C1 - C6 fluorinated alkyl group. In other embodiments, one or more of the alkyl, alkenyl, alkynyl, alkoxy, dialkylamino, aryl, and / or electron - withdrawing group in Formula IA or IB are unsubstituted.

[0078] In certain embodiments, the silacycloalkane precursors having the structures represented by Formula IA or IB can be prepared by reacting 1,3-dihalo-1,3-dialkyl-1,3-disilacyclobutane or 1,1,3,3-tetrahalo-1,3-disilacyclobutane or 1,3,5-trihalo-1,3,5-trialkyl-1,3,5-trisilacyclohexane or 1,1-dihalo-3,3-dialkyl-1,3-disilacyclobutane with various metal alkyl reagents such as XMR 2 (where M = magnesium) in an organic solvent or solvent mixture, as shown in Equations (1) to (3).

[0079]

[0080] In Equations (1)-(2), R 1 and R 2 are the same as the substituents described in Formula I, and X is selected from chlorine, bromine, and iodine. The following Equations (1)-(3) provide non-limiting examples of reaction schemes or synthetic routes that can be used to prepare the silacycloalkane precursors having the structures represented by Formula IA or IB as described herein. The reactions in Equations (1) to (3) can be carried out with an organic solvent (e.g., in the presence of an organic solvent) or without an organic solvent (e.g., in the absence of an organic solvent). In embodiments where an organic solvent is used, examples of suitable organic solvents include, but are not limited to, hydrocarbons such as hexanes, octane, toluene, and ethers such as diethyl ether and tetrahydrofuran (THF). In these or other embodiments, the reaction temperature is in the range of about -70 °C to the boiling point of the solvent used (if a solvent is used). The resulting silacycloalkane can be purified, for example, by vacuum distillation or sublimation after removing all by-products and any solvent (if present). Equations (1) to (2) are two examples of synthetic routes for preparing the silacycloalkane precursors having the structures represented by Formula IA or IB. Other synthetic routes involving cyclization can also be employed.

[0081] The silacycloalkane precursors having the structures represented by Formula IA or IB are preferably substantially free of halide ions such as chloride or metal ions such as Al. As used herein, the term "substantially free" when referring to halide ions (or halides) such as, for example, chloride and fluoride, bromide, iodide, and metal ions such as Li + , Mg 2+ , Al 3+ , Fe 2+ , Fe 3+ , Ni 2+ , Cr 3+When referring to <5 ppm (by weight), preferably <3 ppm as measured by ion chromatography (IC) or ICP-MS, more preferably <1 ppm as measured by ion chromatography (IC) or ICP-MS, and most preferably 0 ppm as measured by ion chromatography (IC). Chloride or metal ions are known to act as degradation catalysts for silacycloalkane precursors. A significant level of chloride in the final product can cause degradation of the silacycloalkane precursor. Gradual degradation of the silacycloalkane precursor can directly affect the film deposition process, making it difficult for semiconductor manufacturers to meet film specifications. Additionally, a higher degradation rate of the silacycloalkane precursor has a negative impact on shelf life or stability, making it difficult to guarantee a shelf life of 1-2 years. Therefore, the accelerated decomposition of the silacycloalkane precursor poses safety and performance issues related to the formation of these flammable and / or self-igniting gaseous by-products.

[0082] In some embodiments, a stabilizer compound or polymerization inhibitor is added to the distillable silacycloalkane precursor having the structure represented by Formula IA or IB. Exemplary stabilizer compounds include 2,6-di-tert-butyl-4-methylphenol (or BHT, representing butylated hydroxytoluene), 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), 2-tert-butyl-4-hydroxyanisole, 3-tert-butyl-4-hydroxyanisole, propyl 3,4,5-trihydroxybenzoate, 2-(1,1-dimethylethyl)-1,4-benzenediol, diphenylpicrylhydrazyl, 4-tert-butylcatechol, tert-butylhydroquinone, 1,4-benzoquinone, 6-tert-butyl-2,4-xylenol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 1,1-diphenyl-2-2-picrylhydrazyl radical, hydroquinone, 4-methoxyphenol, phenothiazine, N-methylaniline, p-methoxydiphenylamine, diphenylamine, N,N'-diphenyl-p-phenylenediamine, p-hydroxydiphenylamine, phenol, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tetrakis(methylene(3,5-di-tert-butyl)-4-hydroxy-hydrocinnamate)methane, phenothiazines, alkylamidoureas, thiodiethylene bis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamate, 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine, tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, cyclic neopentanetetrayl bis(octadecyl phosphite), 4,4'-thiobis(6-tert-butyl-m-cresol), 2,2'-methylenebis(6-tert-butyl-p-cresol), oxalyl bis(benzylidenehydrazide) and naturally occurring antioxidants such as raw seed oil, wheat germ oil, tocopherols and gums. The function of the stabilizer compound or polymerization inhibitor is to prevent the self-polymerization or oligomerization of the silacycloalkane precursor. Based on gas chromatography analysis (GC), the amount of the stabilizer compound or polymerization inhibitor is in the range of about 0.01 to about 10,000 ppm, preferably about 0.01 to about 500 ppm, and most preferably about 0.01 to about 100 ppm.In an important selection, the stabilizer compound or polymerization inhibitor should be volatile and not leave some residues in the pipeline or syringe during the transfer from the container to the CVD chamber by direct liquid injection.

[0083] A method for forming a silicon carbide or silicon carbonitride film or coating is a deposition process. Examples of suitable deposition processes for the methods disclosed herein include, but are not limited to, plasma-enhanced ALD (PEALD) or plasma-enhanced cyclic CVD (PECCVD) or plasma-enhanced flowing chemical vapor 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 that 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 that deposits a film of material onto a substrate having a different composition. Although the precursors, reagents, and sources used herein may sometimes be described as "gaseous," it should be understood that the precursors can be liquids or solids that are transported to the reactor by direct vaporization, bubbling, or sublimation, with or without an inert gas. In some cases, the vaporized precursor can pass through a plasma generator. In one embodiment, a silicon nitride film is deposited using an ALD process. In another embodiment, a silicon nitride film is deposited using a CCVD process. In another embodiment, a silicon nitride film is deposited using a thermal CVD process. As used herein, the term "reactor" includes, but is not limited to, a reaction chamber or a deposition chamber. An ALD-like process is defined herein as a cyclic CVD process that provides a highly conformal silicon nitride film, such as silicon nitride or silicon carbonitride, on a substrate, as shown by at least one of the following: a non-uniformity percentage of about 10% or less (e.g., about 1 to about 10%, about 1 to about 5%, and in some cases about 1 to about 3%) as measured by ellipsometry, per cycle or higher (e.g., about 1 to about about 1 to about per cycle and in some cases about 1 to about per cycle ) of deposition rate, or a combination thereof.

[0084] In certain embodiments, the methods disclosed herein avoid premature reaction of the precursors by using a PEALD or PECCVD or PEFCVD method that separates the precursors before and / or during introduction into the reactor. In this regard, deposition techniques such as PEALD or PECCVD or PEFCVD processes are used to deposit silicon nitride films. In one embodiment, the film is deposited by alternately exposing the substrate surface to one or more silicon nitride precursors, nitrogen-containing sources, or other precursors or reagents via a PEALD process. 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 surface of the substrate is saturated, film growth stops.

[0085] In certain embodiments, the methods described herein further include one or more additional silicon precursors other than the silacycloalkane precursors having the structures represented by Formula IA or IB. Examples of additional silicon nitride precursors include, but are not limited to, monochlorosilane, dichlorosilane, hexachloro-disilane, diisopropylaminosilane, di-sec-butylaminosilane, bis(tert-butylamino)silane, bis(diethylamino)silane, tris(dimethylamino)silane, bisdiisopropylamino-disilane, trimethylsilylamine, and bis(dimethylsilylamino)silane.

[0086] Depending on the deposition method, in certain embodiments, at least one silacycloalkane precursor can be introduced into the reactor in a predetermined molar volume or in an amount of from about 0.1 to about 1000 micromoles. In this or other embodiments, the at least one silacycloalkane precursor can be introduced into the reactor for a predetermined period of time. In certain embodiments, the period of time ranges from about 0.001 seconds to about 500 seconds. In yet another embodiment, the at least one silacycloalkane can be introduced at a fixed flow rate in the range of 100 mg / min to 5 g / min.

[0087] In certain embodiments, the silicon nitride film comprises silicon and nitrogen. In these embodiments, the silicon nitride film deposited using the methods described herein is formed in the presence of a nitrogen source. The nitrogen 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 in the deposition process. Suitable nitrogen source gases can include, for example, nitrogen / argon plasma. In certain embodiments, the nitrogen source includes a nitrogen / argon plasma source gas that is introduced into the reactor at a flow rate in the range of about 1 to about 2000 standard cubic centimeters per minute (sccm) or about 1 to about 1000 sccm. The nitrogen source can be introduced for a time in the range of about 0.1 to about 100 seconds. In embodiments where the film is deposited by ALD or cyclic CVD processes, the precursor pulse can have a pulse duration greater than 0.01 seconds, and the nitrogen source can have a pulse duration less than 0.01 seconds, while the water pulse duration can have a pulse duration less than 0.01 seconds. In yet another embodiment, the purge duration between pulses can be as low as 0 seconds or pulsed continuously without a purge therebetween.

[0088] In the methods described herein, a nitrogen-containing plasma comprising a nitrogen-containing gas (e.g., but not limited to nitrogen gas) and optionally a noble gas, preferably an inert gas having an atomic mass greater than the atomic mass of nitrogen (i.e., 28 amu), can be generated in-situ or remotely. The presence of a noble gas having an atomic mass greater than the atomic mass of nitrogen is believed to generate more atomic nitrogen radicals. The nitrogen plasma source gas is introduced into the reactor at a flow rate in the range of about 1 to about 2000 standard cubic centimeters per minute (sccm) or about 1 to about 1000 sccm or higher. The nitrogen-containing plasma can be introduced for a time in the range of about 0.01 to about 100 seconds or longer. In an embodiment, the precursor pulse can have a pulse duration greater than 0.01 seconds, and the nitrogen-containing plasma can have a pulse duration less than 0.01 seconds, while the water pulse duration can have a pulse duration less than 0.01 seconds. In yet another embodiment, the purge duration between the precursor pulse and the nitrogen plasma can be as low as 0 seconds. In yet another embodiment, when a hydrogen plasma can be used, a pure hydrogen gas (H2) mixed with a noble gas can be used to generate a hydrogen plasma in-situ or remotely. The weight percentage of the noble gas in the plasma comprising both nitrogen and the noble gas can vary from 1 wt% to 99 wt%, and the weight percentage of the noble gas in the plasma comprising both hydrogen and the noble gas can also vary from 1 wt% to 99 wt%. In yet another embodiment, when an ammonia plasma can be used, pure ammonia (NH3) mixed with a noble gas can be used to generate an ammonia plasma in-situ or remotely. The weight percentage of the noble gas in the plasma comprising both ammonia and the noble gas can also vary from 1 wt% to 99 wt%.

[0089] The deposition methods described herein can involve one or more purge gases. The purge gas used to purge away unconsumed reactants and / or reaction by-products is an inert gas that does not react with the precursors. Exemplary purge gases include, but are not limited to, argon (Ar), nitrogen (N2), helium (He), neon (Ne), hydrogen (H2), and mixtures thereof. In certain embodiments, the inert gas used as the purge gas comprises a noble gas. As used herein, the term "noble gas" refers to those gases found in Group 18 of the periodic table, including helium (He), neon (Ne), argon (Ar), xenon (Xe), krypton (Kr), and mixtures thereof. In a particular embodiment, the noble gas used as the purge gas comprises argon. In this or other embodiments, the purge gas comprising Ar is supplied to the reactor at a flow rate in the range of about 10 to about 2000 sccm for about 0.1 to 1000 seconds to purge any unreacted precursor material and any by-products that may remain in the reactor.

[0090] The corresponding steps of supplying the precursor, nitrogen source and / or other precursors, source gases and / or reagents can be carried out by changing the time of supplying them to change the stoichiometric composition of the resulting silicon nitride film.

[0091] Energy is applied to at least one of the precursor, nitrogen source, reducing agent, other precursors or combinations thereof to initiate a reaction and form a silicon nitride film or coating on a substrate. Such energy can be provided by, but not limited to, heat, plasma, pulsed plasma, helicon wave plasma, high density plasma, inductively coupled plasma, X-ray, electron beam, photon, remote plasma methods (including remote microwave plasma) and combinations thereof. In certain embodiments, a secondary RF source can be used to alter the plasma characteristics at the substrate surface. In embodiments where deposition involves plasma, the plasma generation process can include a direct plasma generation process (where plasma is generated directly in the reactor) or a remote plasma generation process (where plasma is generated outside the reactor and supplied into the reactor).

[0092] The silacycloalkane precursor can be delivered to a single wafer or batch reaction chamber, such as a PEALD or PECCVD or PEFCVD reactor, in various ways, such as bubbling, vapor pumping or direct liquid injection (DLI). In one embodiment, a liquid delivery system can be used. In alternative embodiments, a combined liquid delivery and flash evaporation processing unit, such as a Turbo Evaporator manufactured by MSP Corporation, 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 the liquid delivery mode, the precursors described herein can be delivered in pure liquid form or can be used in a solvent formulation or composition containing them. Thus, in certain embodiments, the precursor formulation can contain a solvent component having suitable properties (such as can be desirable and advantageous in a given end use application) to form a film on a substrate. Exemplary solvents can include, but are not limited to, ethers, tertiary amines, alkyl hydrocarbons, aromatic hydrocarbons, tertiary amino ethers and combinations thereof. In certain embodiments, the difference between the boiling point of the silacycloalkane precursor of formula IA or IB and the boiling point of the solvent is 40 °C or less. The weight % of the silacycloalkane precursor compound in the solvent can vary from 1 to 99 wt%, or 10 to 90 wt%, or 20 to 80 wt%, or 30 to 70 wt%, or 40 to 60 wt%, or 50 to 50 wt%. In some embodiments, the composition can be delivered to the reaction chamber for a silicon-containing film by direct liquid injection.

[0093] In certain embodiments, the gas line connecting the precursor canister to the reaction chamber is heated to one or more temperatures depending on process requirements, and the container of the silacycloalkane precursor having the structure represented by Formula IA or IB as described herein is maintained at one or more temperatures for bubbling. In other embodiments, a solution containing at least one silicon nitride precursor having the formula as described herein is injected into an evaporator maintained at one or more temperatures for direct liquid injection.

[0094] A flow of argon, noble gas, and / or other inert gas can be used as a carrier gas to assist in delivering the vapor of at least one silacycloalkane precursor to the reaction chamber during a precursor pulse. In certain embodiments, the reaction chamber process pressure is about 2 Torr or less. In other embodiments, the reaction chamber process pressure is about 10 Torr or less.

[0095] In a typical PEALD or PECCVD or PEALD-like process or PEFCVD, a substrate such as, but not limited to, silicon oxide, polysilicon, silicon doped with germanium, silicon doped with boron, germanium, carbon-doped silicon oxide, a flexible substrate, or a metal nitride substrate is heated on a heater stage in the reaction chamber and is initially exposed to the silicon nitride precursor to allow chemisorption of the silacycloalkane onto the surface of the substrate. A purge gas (e.g., nitrogen, argon, or other inert gas) purges the unabsorbed excess silacycloalkane from the processing chamber. After sufficient purging, a nitrogen source can be introduced into the reaction chamber to react with the adsorbed surface, followed by another gas purge to remove reaction by-products from the reaction chamber. This process cycle can be repeated to achieve the desired film thickness. In other embodiments, unabsorbed excess silacycloalkane can be removed from the process chamber using vacuum pumping, and after sufficient evacuation under pumping, a plasma source can be introduced into the reaction chamber to react with the adsorbed surface, followed by another pumping purge to remove reaction by-products from the chamber.

[0096] In one aspect, a method of forming a dielectric film comprising silicon and carbon is provided, the method comprising the steps of:

[0097] a. Providing a substrate in a reactor;

[0098] b. Introducing at least one silacycloalkane precursor selected from the compounds represented by Formula IA structure and the compounds represented by Formula IB structure into the reactor:

[0099]

[0100] wherein R 1 is selected from hydrogen, straight-chain or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, straight-chain or branched C2 to C 10 alkenyl, and straight-chain or branched C2 to C 10 alkynyl; and R2 Selected from linear or branched C2-C6 alkenyl, linear or branched C2-C6 alkynyl, and cyclic C3-C 10 alkyl, wherein at least one silacycloalkane precursor reacts on at least a portion of the surface of the substrate to provide a chemisorbed layer;

[0101] c. Purge the reactor with a purge gas;

[0102] d. Introduce a plasma-containing source into the reactor to react with at least a portion of the chemisorbed layer and provide at least one reactive site, wherein the plasma is generated at a power density in the range of about 0.01 to about 1.5 W / cm 2 ; and

[0103] e. Optionally purge the reactor with an inert gas; and

[0104] wherein steps b to e are repeated until a silicon carbide film of a desired thickness is obtained.

[0105] A flow of argon, noble gas, and / or other inert gas can be used as a carrier gas to assist in delivering the vapor of the at least one silacycloalkane precursor to the reaction chamber during the precursor pulse. In certain embodiments, the process pressure in the reaction chamber is about 10 Torr or less. In other embodiments, the process pressure in the reaction chamber is about 2 Torr or less. In certain embodiments of the method, the plasma comprises hydrogen selected from hydrogen plasma, hydrogen / helium, hydrogen / argon plasma, hydrogen / neon plasma, and mixtures thereof. In some embodiments, the plasma contains an inert gas selected from helium plasma, argon plasma, neon plasma, and mixtures thereof.

[0106] In another aspect, the present invention relates to a method for forming a dielectric film containing silicon, nitrogen, and carbon on at least one surface of a substrate, the method comprising the steps of:

[0107] a. Providing a substrate in a reactor;

[0108] b. Introducing at least one silacycloalkane precursor selected from the compounds represented by the formula IA structure and the compounds represented by the formula IB structure into the reactor:

[0109]

[0110] wherein R 1 is selected from hydrogen, linear or branched C1-C 10 alkyl, cyclic C3-C 10 alkyl, linear or branched C2-C 10 alkenyl, and linear or branched C2-C 10 alkynyl; and R 2Selected from linear or branched C2-C6 alkenyl, linear or branched C2-C6 alkynyl, and cyclic C3-C 10 alkyl, wherein at least one silacycloalkane precursor reacts on at least a portion of the surface of the substrate to provide a chemisorbed layer;

[0111] c. Purge the reactor with a purge gas comprising at least one selected from nitrogen, noble gases, and combinations thereof;

[0112] d. Introduce a nitrogen-containing source plasma into the reactor to react with at least a portion of the chemisorbed layer and provide at least one reactive site, wherein the plasma is generated at a power density of about 0.01 to about 1.5 W / cm 2 ; and

[0113] e. Optionally purge the reactor with an inert gas; and

[0114] wherein steps b to e are repeated until a silicon nitride film of a desired thickness is obtained. In some embodiments, the nitrogen-containing source plasma 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. Suitable nitrogen-containing source gases can include, for example, ammonia, hydrazine, monoalkylhydrazine, dialkylhydrazine, nitrogen plasma, nitrogen / hydrogen, nitrogen / helium, nitrogen / argon plasma, ammonia plasma, nitrogen / ammonia plasma, ammonia / helium plasma, ammonia / argon plasma, ammonia / nitrogen plasma, NF3 plasma, organic amine plasma, and mixtures thereof. In other embodiments, the plasma is selected from hydrogen plasma, helium plasma, neon plasma, argon plasma, xenon plasma, hydrogen / helium plasma, hydrogen / argon plasma, and mixtures thereof.

[0115] The above steps define one cycle of the method described herein, and the cycle can be repeated until a silicon nitride film of a desired thickness is obtained. In this or other embodiments, it should be understood that the steps of the method 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 corresponding steps of supplying the precursor and the oxygen-containing source can be carried out by changing the length of time for which they are supplied to vary the stoichiometric composition of the resulting silicon nitride film, although always using less nitrogen relative to the stoichiometric amount of available silicon.

[0116] In another aspect, the present invention relates to a method of forming a dielectric film comprising silicon, carbon, nitrogen, and hydrogen on the surface of a substrate or in features etched into the substrate surface, the method comprising the following steps:

[0117] a. Provide a substrate in a reactor;

[0118] b. Introduce at least one silacycloalkane precursor selected from the compounds represented by the formula IA structure and the compounds represented by the formula IB structure into the reactor:

[0119]

[0120] wherein R 1 is selected from hydrogen, linear or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, linear or branched C2 to C 10 alkenyl and linear or branched C2 to C 10 alkynyl; and R 2 is selected from linear or branched C2 to C6 alkenyl, linear or branched C2 to C6 alkynyl and cyclic C3 to C 10 alkyl, wherein the at least one silacycloalkane precursor reacts with radicals generated from a remote plasma source.

[0121] The silacycloalkane precursor is transported to the processing chamber through vapor extraction from the liquid, or is transported as a liquid to a heated syringe that vaporizes the liquid, which is purged by a carrier gas into a dual plenum showerhead that isolates the silacycloalkane precursor from the radicals before entering the processing space above the substrate. Meanwhile, the RPS is used to dissociate reactants such as ammonia (NH3), and these reactive radicals are transported to the process chamber through separate holes in the showerhead, so that they react with the silacycloalkane precursor to produce reactive species, which can be oligomers that condense upon impact with the cooled substrate and flow into the etched features. In certain embodiments, this process can be repeated to improve the mobility into the features.

[0122] After depositing the flowable film, the wafer is then heated to a temperature of about 200 °C to about 400 °C, preferably 300 °C, to evaporate low molecular weight reactive species. Subsequent exposure to a higher energy source such as UV is used to densify and crosslink the film. The PEFCVD film tends to have a density in the range of 1.2–2.2 g / cm 3 range.

[0123] In certain embodiments of the methods described herein, steps b to e are repeated to provide a thickness in the range of about 0.1 to about or about 0.1 to about or about 0.1 to about or about 0.1 to about or 0.1 to A dielectric film containing silicon and carbon or a dielectric film containing silicon, nitrogen and carbon within a certain range. In a specific embodiment of the method described herein, a hydrogen-containing plasma can be inserted before step d to help remove hydrocarbons generated from the reaction between silacycloalkanes and the surface. The hydrogen-containing plasma is selected from hydrogen plasma, hydrogen / helium, hydrogen / argon plasma, hydrogen / neon plasma, and mixtures thereof.

[0124] In one aspect, a method for depositing a dielectric film containing silicon and carbon by plasma-enhanced flowable chemical vapor deposition is provided. The method includes:

[0125] Placing a substrate having surface features in a reactor at one or more temperatures in the range of -20°C to about 200°C;

[0126] Introducing at least one silacycloalkane precursor selected from the compounds represented by the formula IA structure and the compounds represented by the formula IB structure into the reactor:

[0127]

[0128] wherein R 1 is selected from hydrogen, linear or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, linear or branched C2 to C 10 alkenyl, and linear or branched C2 to C 10 alkynyl; and R 2 is selected from linear or branched C2 to C6 alkenyl, linear or branched C2 to C6 alkynyl, and cyclic C3 to C 10 alkyl; and

[0129] Providing a plasma source to the reactor to cause at least partial reaction of the first and second compounds to form a flowable liquid, wherein the flowable liquid at least partially fills a part of the surface features. The flowable liquid contains at least one oligomer.

[0130] The above steps define a cycle of the method described herein; and this cycle can be repeated until a silicon-containing film of the desired thickness is obtained. In a particular embodiment, the substrate temperature is from about -20 °C to about 200 °C, preferably from about -20 °C to about 100 °C or lower, to maintain the resulting polymeric material with a small molecular weight compared to those formed at higher temperatures, and thus higher fluidity to allow filling of smaller features. In this embodiment, the plasma source can be generated in-situ or remotely. When a remote plasma source is employed, the plasma must be delivered through the holes in the showerhead into the processing chamber, which is independent of the delivery of the vapor of the silacycloalkane precursor. In a portion of this embodiment, one plasma source, either in-situ or remote, is employed. In this or other embodiments, both in-situ and remote plasmas can be employed. In this or other embodiments, it should be understood that the steps of the method 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 corresponding steps of supplying the compound and other reagents can be carried out by varying the length of time of supplying them to vary the stoichiometric composition of the resulting silicon-containing film.

[0131] In one aspect, there is provided a method for depositing a dielectric film comprising silicon and carbon or a dielectric film comprising silicon, nitrogen, and carbon by plasma-enhanced flowable chemical vapor deposition, the method comprising:

[0132] Placing a substrate comprising surface features in a reactor at one or more temperatures in the range of -20 °C to about 400 °C;

[0133] Introducing at least one silacycloalkane precursor selected from the compounds represented by Formula IA and the compounds represented by Formula IB into the reactor:

[0134]

[0135] wherein R 1 is selected from hydrogen, straight-chain or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, straight-chain or branched C2 to C 10 alkenyl, and straight-chain or branched C2 to C 10 alkynyl; and R 2 is selected from straight-chain or branched C2 to C6 alkenyl, straight-chain or branched C2 to C6 alkynyl, and cyclic C3 to C 10 alkyl;

[0136] Introducing a second compound having at least one Si-H bond into the reactor, wherein the at least one second compound is selected from Formulas IIA to IIH and III:

[0137] IIA. Having the formula Si xH 2x+2 polysilane compound, where x is a number from 2 to 6;

[0138] IIB. A compound having the formula R 1 m SiH 4-m , where R 1 is selected from hydrogen and straight-chain or branched C1 to C 10 alkyl; and m is a number selected from 1, 2, and 3;

[0139] IIC. A compound having the formula SiH3-R 2 -SiH3, where R 2 is a straight-chain or branched C1 to C6 alkylene;

[0140] IID. A compound having the formula R 3 SiH2-R 2 -SiH2R 4 , where R 2 is a straight-chain or branched C1 to C6 alkylene; R 3 is selected from hydrogen, straight-chain or branched C1 to C 10 alkyl, and C4 to C 10 aryl; and R 4 is selected from straight-chain or branched C1 to C 10 alkyl;

[0141] IIE. A compound having the formula (R 3 R 4 N) n SiH 3-n R 1 , where R 1 is selected from hydrogen and straight-chain or branched C1 to C 10 alkyl; R 3 is selected from hydrogen, straight-chain or branched C1 to C 10 alkyl, and C4 to C 10 aryl; and R 4 is selected from straight-chain or branched C1 to C 10 alkyl;

[0142] IIF. Silylcycloalkyl compounds, such as 1,3-disilacyclobutane or its derivatives, or 1,3,5-trisilacyclohexane and its derivatives;

[0143] IIG. Trimethylsilylamine compounds or their derivatives; and

[0144] IIH. A compound having the formula [(R 3 R 4 N) p SiH 3-p 2NR 1 or [R 3p SiH 2-p NR 1 q The silazane compound of, wherein R 1 is selected from hydrogen and linear or branched C1 to C 10 alkyl; R 3 is selected from hydrogen, branched C1 to C 10 alkyl and C4 to C 10 aryl; and R 4 is selected from linear or branched C1 to C 10 alkyl; p = 0, 1, 2; q = 2 or 3; and

[0145] III. The organoamino disilane having the formula (R 3 R 4 N)SiH2SiH3, wherein R 3 is selected from hydrogen, branched C1 to C 10 alkyl and C4 to C 10 aryl; and R 4 is selected from linear or branched C1 to C 10 alkyl; and

[0146] A plasma source is provided to the reactor to cause at least partial reaction of the first and second compounds to form a flowable liquid or oligomer, wherein the flowable liquid or oligomer at least partially fills a portion of the surface features.

[0147] The above steps define one cycle of the method described herein; and the cycle can be repeated until a silicon-containing film of a desired thickness is obtained. In a particular embodiment, the substrate temperature is about 100 °C or lower to maintain the resulting polymerized polysilazane material having a small molecular weight compared to those formed at higher temperatures, and thus higher fluidity to allow filling of smaller features. In this or other embodiments, it should be understood that the steps of the method 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 corresponding steps of supplying the compound and other reagents can be carried out by changing the length of time of supplying them to change the stoichiometric composition of the resulting silicon-containing film. In certain embodiments, after depositing the silicon-containing film, the substrate is optionally treated with an oxygen-containing source under certain process conditions sufficient to form a silicon oxide, silicon oxynitride, or carbon-doped silicon oxide film from the silicon nitride or silicon carbide film. The oxygen-containing source can be selected from water (H2O), oxygen (O2), hydrogen peroxide (H2O2), oxygen plasma, ozone (O3), NO, N2O, carbon monoxide (CO), carbon dioxide (CO2), N2O plasma, carbon monoxide (CO) plasma, carbon dioxide (CO2) plasma, and combinations thereof.

[0148] ​In any of the above or alternative embodiments, the flowable liquid or oligomer is treated at one or more temperatures in the range of about 100 °C to about 1000 °C to densify at least a portion of the material.

[0149] In some embodiments, the heat-treated material is exposed to plasma, infrared light, chemical treatment, electron beam, or UV light to form a dense film. In one embodiment of the present invention, the post-treatment including exposure to UV light is carried out under conditions that emit hydrocarbon or silane gaseous by-products to densify the dielectric film.

[0150] In certain embodiments, the resulting silicon carbide or silicon carbonitride-containing film or coating can be exposed to post-deposition treatments such as, but not limited to, plasma treatment, chemical treatment, ultraviolet light exposure, vacuum UV exposure, excimer laser exposure, electron beam exposure, and / or other treatments that affect one or more properties of the film. In a specific embodiment of the methods described herein, a hydrogen-containing plasma can be used as a post-deposition treatment for such deposited silicon nitride films to increase density and reduce the etch rate. The hydrogen-containing plasma is selected from hydrogen plasma, hydrogen / helium, hydrogen / argon plasma, hydrogen / neon plasma, and mixtures thereof.

[0151] In certain embodiments, the silicon carbide or silicon carbonitride-containing films described herein have a dielectric constant of 6 or less. In these or other embodiments, the film can have a dielectric constant of about 5 or less, or about 4 or less, or about 3.5 or less as measured by mercury probe techniques. However, it is contemplated that depending on the desired end use of the film, films with other dielectric constants (e.g., higher or lower) can be formed. Examples of silicon carbide or silicon carbonitride films formed using the silacycloalkane precursors and methods described herein have the formula Si x O y C z N v H w , where Si is in the range of about 10% to about 50%; O is in the range of about 0% to about 10%; C is in the range of about 0% to about 20%; and N is in the range of about 10% to about 75% or about 10% to 60%; and H is in the range of about 0% to about 10% by atomic weight percentage %, where x + y + z + v + w = 100 atomic weight percentage, as determined, for example, by X-ray photoelectron spectroscopy (XPS) or secondary ion mass spectrometry (SIMS).

[0152] In one specific embodiment in which the film is deposited using a plasma comprising a noble gas, the silicon nitride film comprises from about 5% to about 50% carbon atomic weight percent as determined by XPS or other means. In this specific embodiment, the silicon nitride film further comprises Si in the range of from about 10% to about 40%; O in the range of from about 0% to about 5%; N in the range of from about 10% to about 75% or from about 10% to 50%; and H in the range of from about 0% to about 10% atomic weight percent, wherein the total weight percents of the film add up to 100 atomic weight percent.

[0153] Throughout the specification, as used herein, the term "dielectric film" refers to a film selected from stoichiometric or non-stoichiometric silicon carbide, silicon carbonitride, silicon carbon oxynitride, and mixtures thereof.

[0154] Throughout the specification, as used herein, the term "metal alkyl" refers to a reagent having at least one metal-carbon bond, such as MR 2 , wherein M is a metal selected from Li, Na, K, or XMR 2 , wherein X=Cl, Br or I, M=Mg or Ca.

[0155] As previously mentioned, the methods described herein can be used to deposit a silicon nitride film on at least a portion of a substrate. Examples of suitable substrates include, but are not limited to, silicon, silicon / germanium, germanium, III / V materials, SiO2, Si3N4, OSG, FSG, silicon carbide, hydrogenated silicon carbide, silicon nitride, hydrogenated silicon nitride, silicon carbonitride, hydrogenated silicon carbonitride, boron nitride, antireflective coatings, photoresists, flexible substrates such as IGZO, organic polymers, porous organic and inorganic materials, metals such as copper and aluminum, and diffusion barriers such as, but not limited to, TiN, Ti(C)N, TaN, Ta(C)N, Ta, W, or WN. The film is compatible with a variety of subsequent processing steps, such as chemical mechanical planarization (CMP) and anisotropic etching processes.

[0156] The deposited films have applications including, but not limited to, computer chips, optical devices, magnetic information storage, coatings on support materials or substrates, microelectromechanical systems (MEMS), nanoelectromechanical systems, thin film transistors (TFT), light emitting diodes (LED), organic light emitting diodes (OLED), IGZO, and liquid crystal displays (LCD).

[0157] Therefore, the present invention provides at least the following:

[0158] 1. A method for forming a dielectric film comprising silicon and carbon on at least one surface of a substrate, the method comprising the steps of:

[0159] a. providing a substrate in a reactor;

[0160] b. Introduce at least one silacycloalkane precursor selected from the compounds represented by the formula IA structure and the compounds represented by the formula IB structure into the reactor:

[0161]

[0162] wherein R 1 is selected from hydrogen, linear or branched C1 to C 10 alkyl, cyclic C3 to C 10 alkyl, linear or branched C2 to C 10 alkenyl and linear or branched C2 to C 10 alkynyl; and R 2 is selected from linear or branched C2 to C6 alkenyl, linear or branched C2 to C6 alkynyl and cyclic C3 to C 10 alkyl, wherein the at least one silacycloalkane precursor reacts on at least a portion of the surface of the substrate to provide a chemisorbed layer;

[0163] c. Purge the reactor with a purge gas;

[0164] d. Introduce a plasma-containing source and an inert gas into the reactor to react with at least a portion of the chemisorbed layer and provide at least one reactive site, wherein the plasma is generated at a power density of about 0.01 to about 1.5 W / cm 2 ; and

[0165] e. Optionally, purge the reactor with an inert gas; and

[0166] wherein steps b to e are repeated until the dielectric film of the desired thickness is obtained.

[0167] 2. The method according to item 1, wherein the at least one silacycloalkane precursor is selected from 1,3-divinyl-1,3-disilacyclobutane, 1,3-divinyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetravinyl-1,3-disilacyclobutane, 1,3,5-trivinyl-1,3,5-trisilacyclohexane, 1,3,5-trivinyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexavinyl-1,3,5-trisilacyclohexane, 1,3-diallyl-1,3-disilacyclobutane, 1,3-diallyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraallyl-1,3-disilacyclobutane, 1,3,5-triallyl-1,3,5-trisilacyclohexane, 1,3,5-triallyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaallyl-1,3,5-trisilacyclohexane, 1,3-diethynyl-1,3-disilacyclobutane, 1,3-diethynyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraethynyl-1,3-disilacyclobutane, 1,3,5-triethynyl-1,3,5-trisilacyclohexane, 1,3,5-triethynyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaethynyl-1,3,5-trisilacyclohexane, 1,3-dicyclopropyl-1,3-disilacyclobutane, 1,3-dicyclopropyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetracyclopropyl-1,3-disilacyclobutane, and combinations thereof.

[0168] 3. The method according to item 1, wherein the plasma-containing source is selected from hydrogen plasma, hydrogen / helium, hydrogen / argon plasma, hydrogen / neon plasma, helium plasma, argon plasma, neon plasma, and mixtures thereof.

[0169] 4. The method according to item 1, wherein the dielectric film has a density of 2.2 g / cc or higher.

[0170] 5. The method according to item 1, wherein the method is at least one vapor deposition process selected from plasma-enhanced atomic layer deposition, plasma-enhanced cyclic chemical vapor deposition, and plasma-enhanced flowable chemical vapor deposition.

[0171] 6. The method according to item 1, wherein the method is carried out at one or more temperatures of about 400 °C or lower.

[0172] 7. The method according to item 1, wherein the method is carried out at one or more temperatures of about 300 °C or lower.

[0173] 8. A method for forming a silicon carbide or silicon carbonitride film on at least one surface of a substrate, the method comprising the following steps:

[0174] a. Providing a substrate in a reactor;

[0175] b. Introducing at least one silacycloalkane precursor selected from the group consisting of: 1,3-divinyl-1,3-disilacyclobutane, 1,3-divinyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetravinyl-1,3-disilacyclobutane, 1,3,5-trivinyl-1,3,5-trisilacyclohexane, 1,3,5-trivinyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexavinyl-1,3,5-trisilacyclohexane, 1,3-diallyl-1,3-disilacyclobutane, 1,3-diallyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraallyl-1,3-disilacyclobutane, 1,3,5-triallyl-1,3,5-trisilacyclohexane, 1,3,5-triallyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaallyl-1,3,5-trisilacyclohexane, 1,3-diethynyl-1,3-disilacyclobutane, 1,3-diethynyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraethynyl-1,3-disilacyclobutane, 1,3,5-triethynyl-1,3,5-trisilacyclohexane, 1,3,5-triethynyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaethynyl-1,3,5-trisilacyclohexane, 1,3-dicyclopropyl-1,3-disilacyclobutane, 1,3-dicyclopropyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetracyclopropyl-1,3-disilacyclobutane, and combinations thereof, wherein the at least one silacycloalkane reacts on at least a portion of the surface of the substrate to provide a chemisorbed layer;

[0176] c. Purging the reactor with a purge gas comprising at least one selected from the group consisting of nitrogen, noble gases, and combinations thereof;

[0177] d. Introducing a plasma-containing source into the reactor to react with at least a portion of the chemisorbed layer and provide at least one reactive site, wherein the plasma is generated at a power density of about 0.01 to about 1.5 W / cm 2 ; and

[0178] e. Optionally purging the reactor with an inert gas; and

[0179] Repeat steps b to e until the silicon nitride film with the desired thickness is obtained.

[0180] 9. The method according to item 8, wherein the silicon carbide or silicon carbonitride film has a density of 2.2 g / cc or higher.

[0181] 10. The method according to item 8, wherein the method is a vapor deposition process selected from plasma-enhanced atomic layer deposition, plasma-enhanced cyclic chemical vapor deposition, and plasma-enhanced flowable chemical vapor deposition.

[0182] 11. The method according to item 8, wherein the method is carried out at a temperature of 400 °C or lower.

[0183] 12. The method according to item 8, wherein the method is carried out at a temperature of 300 °C or lower.

[0184] 13. The method according to item 8, wherein the method is carried out at a temperature of 100 °C or lower.

[0185] 14. The method according to item 8, wherein the plasma-containing source is selected from hydrogen plasma, hydrogen / helium, hydrogen / argon plasma, hydrogen / neon plasma, helium plasma, argon plasma, neon plasma, nitrogen / argon plasma, ammonia plasma, nitrogen / ammonia plasma, ammonia / helium plasma, ammonia / argon plasma, ammonia / nitrogen plasma, NF3 plasma, organic amine plasma, and mixtures thereof.

[0186] 15. A composition for the chemical vapor deposition of a silicon-containing dielectric film, comprising at least one silacycloalkane precursor selected from: 1,3-bis(tert-butyl)silacycloalkane, 1,3-bis(tert-butyl)-2-methylsilacycloalkane, 1,3-bis(tert-butyl)-2,4-dimethylsilacycloalkane, 1,3-bis(tert-amyl)silacycloalkane, 1,3-bis(tert-amyl)-2-methylsilacycloalkane, 1,3-bis(tert-amyl)-2,4-dimethylsilacycloalkane, 1,3-bis(tert-butyl)-2-chlorocyclodisilazane, 1,3-bis(tert-butyl)-2,4-dichlorosilacycloalkane, 1,3-bis(tert-amyl)-2-chlorocyclodisilazane, 1,3-bis(tert-amyl)-2,4-dichlorosilacycloalkane, 1,3-bis(tert-butyl)-2,4,4-trichlorosilacycloalkane, 1,3-bis(tert-butyl)-2-dimethylsilacycloalkane, 1,3-bis(tert-butyl)-2-chloro-2-methylsilacycloalkane, 1,3-bis(tert-amyl)-2-dimethylsilacycloalkane, 1,3-bis(tert-amyl)-2-chloro-2-methylsilacycloalkane, 1,3-bis(tert-butyl)-2-vinylsilacycloalkane, 1,3-bis(tert-butyl)-2-ethynylsilacycloalkane, 1,3-dicyclopropyl-1,3-disilacyclobutane, 1,3-dicyclopropyl-1,3-dimethyl-1,3-disilacyclobutane, and 1,1,3,3-tetracyclopropyl-1,3-disilacyclobutane, wherein the silacycloalkane precursor is substantially free of one or more impurities selected from halides, water, metal ions, and combinations thereof.

[0187] 16. The composition according to item 15, wherein the halide comprises chloride ions.

[0188] 17. The composition according to item 15, wherein the chloride ion concentration is less than 50 ppm.

[0189] 18. The composition according to item 13, wherein the chloride ion concentration is less than 10 ppm.

[0190] 19. The composition according to item 13, wherein the chloride ion concentration is less than 5 ppm.

[0191] 20. A container for delivering a silacycloalkane precursor for the deposition of a silicon-containing film, the container comprising:

[0192] A silacycloalkane precursor selected from the following: 1,3-bis(tert-butyl)silacycloalkane, 1,3-bis(tert-butyl)-2-methylsilacycloalkane, 1,3-bis(tert-butyl)-2,4-dimethylsilacycloalkane, 1,3-bis(tert-pentyl)silacycloalkane, 1,3-bis(tert-pentyl)-2-methylsilacycloalkane, 1,3-bis(tert-pentyl)-2,4-dimethylsilacycloalkane, 1,3-bis(tert-butyl)-2-chlorocyclodisilazane, 1,3-bis(tert-butyl)-2,4-dichlorosilacycloalkane, 1,3-bis(tert-pentyl)-2-chlorocyclodisilazane, 1,3-bis(tert-pentyl)-2,4-dichlorosilacycloalkane, 1,3-bis(tert-butyl)-2,4,4-trichlorosilacycloalkane, 1,3-bis(tert-butyl)-2-dimethylsilacycloalkane, 1,3-bis(tert-butyl)-2-chloro-2-methylsilacycloalkane, 1,3-bis(tert-pentyl)-2-dimethylsilacycloalkane, 1,3-bis(tert-pentyl)-2-chloro-2-methylsilacycloalkane, 1,3-bis(tert-butyl)-2-vinylsilacycloalkane, 1,3-bis(tert-butyl)-2-ethynylsilacycloalkane, 1,3-bis(tert-butyl)-2-vinylsilacycloalkane, 1,3-bis(tert-butyl)-2-ethynylsilacycloalkane, 1,3-dicyclopropyl-1,3-disilacyclobutane, 1,3-dicyclopropyl-1,3-dimethyl-1,3-disilacyclobutane, and 1,1,3,3-tetracyclopropyl-1,3-disilacyclobutane, wherein the silacycloalkane precursor is substantially free of one or more impurities selected from halides, water, metal ions, and combinations thereof, wherein the purity of the precursor is about 98% or higher, and

[0193] wherein the container has a headspace comprising at least one inert gas selected from helium, argon, nitrogen, and combinations thereof.

[0194] 21. The container according to item 20, wherein the container is made of stainless steel.

[0195] 22. A method for depositing a dielectric film containing silicon and carbon by plasma-enhanced flowable chemical vapor deposition, the method comprising the steps of:

[0196] Placing a substrate having surface features in a reactor at one or more temperatures in the range of -20 °C to about 200 °C;

[0197] Introducing at least one silacycloalkane precursor selected from the compounds represented by formula IA and the compounds represented by formula IB into the reactor:

[0198]

[0199] wherein R 1 is selected from hydrogen, straight-chain or branched C1 to C 10alkyl, cyclic C3 to C 10 alkyl, straight-chain or branched C2 to C 10 alkenyl and straight-chain or branched C2 to C 10 alkynyl; and R 2 selected from straight-chain or branched C2 to C6 alkenyl, straight-chain or branched C2 to C6 alkynyl and cyclic C3 to C 10 alkyl; and

[0200] A plasma source is provided to the reactor to cause at least partial reaction of the first and second compounds to form a flowable liquid, wherein the flowable liquid at least partially fills a portion of the surface feature.

[0201] 23. The method according to item 22, wherein the at least one silacycloalkane precursor is selected from 1,3-divinyl-1,3-disilacyclobutane, 1,3-divinyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetravinyl-1,3-disilacyclobutane, 1,3,5-trivinyl-1,3,5-trisilacyclohexane, 1,3,5-trivinyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexavinyl-1,3,5-trisilacyclohexane, 1,3-diallyl-1,3-disilacyclobutane, 1,3-diallyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraallyl-1,3-disilacyclobutane, 1,3,5-triallyl-1,3,5-trisilacyclohexane, 1,3,5-triallyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaallyl-1,3,5-trisilacyclohexane, 1,3-diethynyl-1,3-disilacyclobutane, 1,3-diethynyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraethynyl-1,3-disilacyclobutane, 1,3,5-triethynyl-1,3,5-trisilacyclohexane, 1,3,5-triethynyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaethynyl-1,3,5-trisilacyclohexane, 1,3-dicyclopropyl-1,3-disilacyclobutane, 1,3-dicyclopropyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetracyclopropyl-1,3-disilacyclobutane, and combinations thereof.

[0202] 24. The method according to item 22, wherein the deposition process is plasma-enhanced chemical vapor deposition and the plasma is generated in situ.

[0203] 25. The method according to item 22, wherein the deposition process is plasma enhanced chemical vapor deposition, and the plasma is remotely generated.

[0204] 26. The method according to item 22, wherein the deposition process is plasma enhanced chemical vapor deposition, and the plasma comprises a dual plasma source, one source being in-situ generated and one source being remotely generated.

[0205] 27. The method according to item 22, wherein the reactor is at one or more temperatures in the range of -20 °C to about 100 °C.

[0206] 28. The method according to item 22, wherein the flowable liquid comprises at least one oligomer.

[0207] 29. A silicon-containing film produced by the method according to item 1.

[0208] 30. A silicon-containing film produced by the method according to item 22.

[0209] The following examples illustrate the method for depositing a silicon nitride film described herein and are not intended to limit in any way the appended claims herein.

[0210] Embodiment

[0211] In the following examples, unless otherwise stated, properties were obtained from sample films deposited on a medium resistivity (14 - 17 Ω-cm) single crystal silicon wafer substrate. All film depositions were carried out using a commercial reactor with a showerhead design having a 13.56 MHz direct plasma. Under typical process conditions, unless otherwise stated, the chamber pressure was fixed at a pressure in the range of about 1 to about 10 Torr. An additional inert gas was used to maintain the chamber pressure. The silacycloalkane precursor was delivered using vapor pumping (i.e., without using argon at all). The typical RF power used was 125 W over the electrode area of a 150 mm wafer to provide a power density of 0.7 W / cm 2 The power density. Film deposition includes the steps listed in Table 1 for thermal ALD and plasma enhanced ALD respectively. Steps 1 to 4 in Table 1 constitute one PEALD cycle and are repeated (unless otherwise stated) a total of 300 times to obtain the desired film thickness.

[0212] Table 1. Steps used in PEALD silicon carbide film

[0213]

[0214] The refractive index (RI) and thickness of the deposited film were measured using an ellipsometer. The non-uniformity of the film was calculated using a standard equation: % 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 using X-ray reflectometry (XRR).

[0215] Embodiment 1 : Synthesis of 1,1,3,3 - Tetravinyl - 1,3 - disilacyclobutane

[0216] A solution of vinylmagnesium chloride in THF (4 L, 1.6 M) was charged into a 12 L flask equipped with a mechanical stirrer, thermocouple well, condenser, and addition funnel. A solution of 1,1,3,3 - tetrachloro - 1,3 - disilacyclobutane (339.0 g, 1.5 mol) in hexane (500 ml) was slowly added to the flask at an addition rate that kept the reaction temperature below 60 °C. After the addition was complete, the flask was heated to 60 °C for 4 hours and cooled to room temperature. With stirring, cold water (1.5 L) was slowly added to the flask through the addition funnel. Two liquid layers formed. The organic layer was separated and dried over Na2SO4. After removing the solvent by distillation, the product was distilled under vacuum. 185.0 g of the product was obtained, yield: 65.4%. The normal boiling point measured by DSC was 201.5 °C.

[0217] Embodiment 2 : Synthesis of 1,3 - Divinyl - 1,3 - dimethyl - 1,3 - disilacyclobutane

[0218] A solution of vinylmagnesium chloride in THF (3 L, 1.6 M) was charged into a 12 L flask equipped with a mechanical stirrer, thermocouple well, condenser, and addition funnel. A solution of 1,3 - diethoxy - 1,3 - dimethyl - 1,3 - disilacyclobutane (408.0 g, 2.0 mol) in hexane (500 ml) was slowly added to the flask at an addition rate that kept the reaction temperature below 60 °C. After the addition was complete, the flask was heated to 60 °C for 4 hours and cooled to room temperature. With stirring, cold water (1.5 L) was slowly added to the flask through the addition funnel. Two liquid layers formed. The organic layer was separated and dried over Na2SO4. After removing the solvent by distillation, the product was distilled under vacuum. 261.5 g of the product was obtained, having b.p. 62 °C / 20 mmHg, yield: 78.0%.

[0219] Embodiment 3 : Plasma - enhanced atomic layer deposition (PEALD) of silicon carbide films using 1,3 - divinyl - 1,3 - dimethyl - silacyclobutane and hydrogen plasma (preliminary)

[0220] Load a silicon wafer into a commercial reactor equipped with a showerhead design with 13.56 MHz direct plasma and heat it to 300 °C at a chamber pressure of 2 Torr. Deliver 1,3-divinyl-1,3-dimethyl-silacyclobutane, a silicon heterocycloalkane precursor, to the reactor using vapor pumping at a temperature of 72 °C. The ALD cycle consists of the process steps provided in Table 1 and uses the following process parameters:

[0221] a. Introduce the silicon heterocycloalkane precursor into the reactor

[0222] Nitrogen gas flow: 1000 sccm

[0223] Silicon heterocycloalkane precursor pulse: 1 second

[0224] b. Inert gas purge

[0225] Nitrogen gas flow: 1000 sccm

[0226] Purge time: 10 seconds

[0227] c. Introduce hydrogen plasma

[0228] Hydrogen gas flow: 1000 sccm

[0229] Hydrogen plasma pulse: 10 seconds, plasma power 125 W

[0230] d. Purge

[0231] Nitrogen gas flow: 1000 sccm

[0232] Purge time: 10 seconds

[0233] Steps a to d are repeated 500 cycles to provide a silicon carbide film.

[0234] Embodiment 4 : PEFCVD of silicon carbide film using 1,1,3,3-tetravinyl-1,3-disilacyclobutane

[0235] Load a silicon wafer into a commercial reactor equipped with a dual-pressurized showerhead design and a microwave-based remote plasma source. Deliver 1,1,3,3-tetravinyl-1,3-disilacyclobutane, a silicon heterocycloalkane precursor, through a liquid flow meter and a heated syringe to deliver the vapor through the holes in the showerhead to the processing chamber, which is independent of the delivery of radicals generated from the dissociation of ammonia (NH3) by the remote plasma source. The process conditions for depositing a flowable film are:

[0236]

[0237] After deposition, the film was cured by transferring the wafer to an annealing chamber where it was annealed at 300 °C for 5 minutes without a vacuum break and then to another chamber where it was cured by UV exposure for 10 minutes at a susceptor temperature of 400 °C. The resulting film is shown in Figure 1 , which shows that the flowable silicon carbide completely fills the features from the bottom up, with a planar overcoat above the features. As determined by X-ray photoelectron spectroscopy (XPS), Figure 1 the film shown has the following composition: 74.0 atomic % carbon, <1.0 atomic % nitrogen, 5.0 atomic % oxygen, and 20.0 atomic % silicon. Unexpectedly, ammonia was used as a remote plasma source, but the resulting film has less than 1.0 atomic % nitrogen.

[0238] The precursor has a carbon-silicon ratio of 5:1. The deposited and cured film has a carbon-silicon ratio of <4:1. The combination of the precursor and the process conditions deployed allows for a reduction in the total carbon content of the film relative to the precursor.

[0239] Although the specific principles of the present invention have been described above in connection with various aspects or embodiments, it should be clearly understood that this description is made by way of example only and not as a limitation on the scope of the present invention.

Claims

1. A composition for chemical vapor deposition of a silicon-containing dielectric film, comprising at least one silacycloalkane precursor selected from: 1,3-divinyl-1,3-disilacyclobutane, 1,3-divinyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetravinyl-1,3-disilacyclobutane, 1,3,5-trivinyl-1,3,5-trisilacyclohexane, 1,3,5-trivinyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,3-diallyl-1,3-disilacyclobutane, 1,3-diallyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraallyl-1,3-disilacyclobutane, 1,3,5-triallyl-1,3,5-trisilacyclohexane, 1,3,5-triallyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaallyl-1,3,5-trisilacyclohexane, 1,3-diethynyl-1,3-disilacyclobutane, 1,3-diethynyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraethynyl-1,3-disilacyclobutane, 1,3,5-triethynyl-1,3,5-trisilacyclohexane, 1,3,5-triethynyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaethynyl-1,3,5-trisilacyclohexane, wherein the silacycloalkane precursor comprises less than 5 ppm by weight of one or more impurities selected from halides, water, metal ions, and combinations thereof.

2. The composition according to claim 1, wherein the halide comprises chloride ions.

3. The composition according to claim 2, wherein the chloride ion concentration is less than 50 ppm.

4. The composition according to claim 2, wherein the chloride ion concentration is less than 10 ppm.

5. The composition according to claim 2, wherein the chloride ion concentration is less than 5 ppm.

6. A container for delivering a silacycloalkane precursor for depositing a silicon-containing film, the container comprising: A silacycloalkane precursor selected from the following: 1,3-divinyl-1,3-disilacyclobutane, 1,3-divinyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetravinyl-1,3-disilacyclobutane, 1,3,5-trivinyl-1,3,5-trisilacyclohexane, 1,3,5-trivinyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,3-diallyl-1,3-disilacyclobutane, 1,3-diallyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraallyl-1,3-disilacyclobutane, 1,3,5-triallyl-1,3,5-trisilacyclohexane, 1,3,5-triallyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaallyl-1,3,5-trisilacyclohexane, 1,3-diethynyl-1,3-disilacyclobutane, 1,3-diethynyl-1,3-dimethyl-1,3-disilacyclobutane, 1,1,3,3-tetraethynyl-1,3-disilacyclobutane, 1,3,5-triethynyl-1,3,5-trisilacyclohexane, 1,3,5-triethynyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane, 1,1,3,3,5,5-hexaethynyl-1,3,5-trisilacyclohexane, wherein the silacycloalkane precursor contains one or more impurities selected from halides, water, metal ions, and combinations thereof in an amount less than 5 ppm by weight, wherein the purity of the precursor is 98% or higher, and wherein the container has a headspace containing at least one inert gas selected from helium, argon, nitrogen, and combinations thereof.

7. The container according to claim 6, wherein the container is made of stainless steel.

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