Compositions and methods of using the same for thermal deposition silicon-containing films

Abstract

To provide compositions and methods that solve problems with the prior art by providing a composition or formulation for depositing a silicon-containing film formed without any halogenated precursor (i.e., chlorosilane) or strong oxidizer, such as oxygen plasma or ozone.SOLUTION: A composition used for depositing a silicon oxide film or a carbon-doped silicon oxide film using a deposition process contains at least one silicon precursor having a structure represented by Formula I described herein.SELECTED DRAWING: None

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 62 / 850,717, filed May 21, 2019, the entire contents of which are incorporated herein by reference for all permitted purposes. [Background technology]

[0002] Disclosed herein are compositions and methods for the manufacture of electronic devices. More specifically, disclosed herein are compounds for the deposition of silicon-containing films, such as, but not limited to, silicon oxide films, carbon-doped silicon oxide films, carbon-doped silicon nitride films, carbon-doped silicon oxynitride films, or silicon carbide films, and compositions and methods including the same.

[0003] There is a need in the art to provide compositions and methods using non-halogenated precursors and mild oxidizers for the deposition of silicon-containing films, such as silicon oxide films or carbon-doped silicon oxide films, for specific applications in the semiconductor industry.

[0004] US Pat. Nos. 7,084,076 and 6,992,019 describe methods for the deposition of silicon dioxide films using atomic layer deposition (ALD), in which halogen or NCO substituted siloxanes are used as the Si source.

[0005] U.S. Patent Publication No. 2013 / 022496 teaches a method for forming a dielectric film having Si-C bonds on a semiconductor substrate by ALD, the method including (i) adsorbing a precursor onto a surface of the substrate, (ii) reacting the adsorbed precursor and a reactant gas on the surface, and (iii) repeating steps (i) and (ii) to form a dielectric film having at least Si-C bonds on the substrate.

[0006] US 2014 / 302688 A describes a method for forming a dielectric layer on a patterned substrate, which can include combining a silicon- and carbon-containing precursor with a radical oxygen precursor in a plasma-free substrate processing region in a chemical vapor deposition chamber. The silicon- and carbon-containing precursor and the radical oxygen precursor react to deposit a flowable silicon-carbon-oxygen layer on the patterned substrate.

[0007] US 2014 / 302690 describes a method for forming a low-k dielectric material on a substrate. The method can include flowing an unexcited precursor into a remote plasma region to generate a radical precursor, and reacting the radical precursor with a gas-phase silicon precursor to deposit a flowable film on the substrate. The gas-phase silicon precursor can include at least one silicon and oxygen-containing compound and at least one silicon and carbon binder. The flowable film can be cured to form a low-k dielectric material.

[0008] US 2014 / 051264 describes a method for depositing an initially flowable dielectric film on a substrate. The methods include introducing a silicon-containing precursor into a deposition chamber that contains the substrate. The methods further include generating at least one excited precursor, such as a radical nitrogen or oxygen precursor, in a remote plasma system located outside the deposition chamber. The excited precursor is also introduced into the deposition chamber, where it reacts with the silicon-containing precursor in a reaction zone to deposit an initially flowable film on the substrate. The flowable film can be treated, for example, in a steam environment to form a silicon oxide film.

[0009] International Publication WO 2011 / 043139 A1 describes a raw material containing triisocyanate silane (HSi(NCO) 3 ) for the formation of silicon-containing films.

[0010] International Publication WO2014 / 134476A1 describes a method for depositing a film comprising SiCN and SiCON. A particular method includes exposing a substrate surface to a first and a second precursor, the first precursor being a compound of the formula (X y H 3-y Si) z CH 4-z , (X y H 3-y Si)(CH2)(SiX p H 2-p )(CH2)(SiX y H 3-y ) or (X y H 3-y Si)(CH2) n (SiX y H 3-y ), where X is a halogen, y has a value ranging from 1 to 3, z has a value ranging from 1 to 3, p has a value ranging from 0 to 2, and n has a value ranging from 2 to 5, and the second precursor comprises a reducible amine. Certain methods also include exposing a surface of the substrate to an oxygen source to provide a film comprising SiCON.

[0011] The reference entitled "Quasi-monolayer deposition of silicon dioxide" by Gasser, W, Z. et al., Thin Solid Films, 1994, 250, 213, discloses SiO2 films deposited layer-by-layer from a novel silicon source gas, namely tetraisocyanatosilane (Si(NCO)4).

[0012] The reference entitled "Atomic-layer chemical-vapor-deposition of silicon dioxide films with an extremely low hydrogen content" by Yamaguchi, K. et al., Applied Surface Science, 1998, 130, 212, discloses atomic layer deposition of SiO2 with extremely low H content using Si(NCO)4 and N(C2H5)3.

[0013] The reference entitled “Catalyzed Atomic Layer Deposition of Silicon Oxide at Ultra-low Temperature Using Alkylamine” by Mayangsari, T. et al. reports the catalyzed atomic layer deposition (ALD) of silicon oxide using Si2Cl6, HO and various alkylamines. Summary of the Invention [Problem to be solved by the invention]

[0014] The compositions and methods described herein solve the problems of the prior art by providing compositions or formulations for depositing silicon-containing films that form without any halogenated precursors (i.e., chlorosilanes) or strong oxidizing agents, such as oxygen plasma or ozone. [Means for solving the problem]

[0015] In one embodiment, the deposited film is silicon oxide having impurities, such as less than 1 atomic % nitrogen and carbon, by X-ray photoelectron spectroscopy (XPS). The method includes depositing silicon oxide by thermal ALD using tetraisocyanatosilane (TiCS) and water as a catalyst.

[0016] In other specific embodiments, the compositions described herein can be used in a method for depositing carbon-doped silicon oxide films using thermal ALD, having a carbon content in the range of 1-15 atomic % by X-ray photoelectron spectroscopy (XPS).

[0017] In one embodiment, a composition for depositing a silicon-containing film comprises a silicon compound having at least one isocyanate group and represented by Formula I below: [ka] In the formula, R1 is hydrogen, a straight chain C1-C6 alkyl group, a branched C3-6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 aryl groups, R 2 and R 3 is hydrogen, a C1-C6 linear alkyl group, a branched C3-C6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 aryl groups, which may or may not be joined to form a cyclic ring structure; n is 0, 1, or 2; and m is 0, 1, 2, or 3, where n+m=0, 1, 2, or 3.

[0018] In another aspect, a method is provided for depositing a film selected from a silicon oxide film and a carbon-doped silicon oxide film onto a substrate surface, comprising the steps of: a. placing the substrate in a reactor and heating the reactor to at least one temperature in the range of about 20° C. to about 600° C.; b. introducing a precursor according to formula I above into a reactor, and optionally introducing a catalyst into the reactor; c. purging the reactor with a purge gas; d. providing an oxygen source and optionally a catalyst into the reactor to react with the surface to form an as-deposited film, the catalyst comprising a Lewis base; and e. purging the reactor with a purge gas; Here, steps b through e are repeated until a desired thickness of silicon oxide or carbon-doped silicon oxide is deposited as a silicon-containing film on the substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] One aspect of the invention is directed to silicon compounds having at least one isocyanate group, and compositions comprising same, for depositing silicon-containing films, such as silicon oxides having a carbon and / or nitrogen content preferably less than 1 atomic %, or carbon-doped silicon oxides having a carbon content preferably between about 1 atomic % and 15 atomic %, as measured by XPS. Another aspect of the invention is directed to films deposited using the compositions and methods described herein, which exhibit extremely low etch rates, preferably less than about 0.20 Å / sec or less than about 0.15 Å / sec, in dilute HF, while exhibiting variability in other tunable properties, such as, but not limited to, density, dielectric constant, refractive index, and elemental composition.

[0020] In one embodiment, a composition for depositing a silicon-containing film comprises a silicon compound having at least one isocyanate group having Formula I below: [ka] In the formula, R 1 are independently selected from hydrogen, a linear C1-C6 alkyl group, a branched C3-6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 aryl groups, R 2 and R 3 is hydrogen, a C1-C6 linear alkyl group, a branched C3-C6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 aryl groups, which may or may not be joined to form a cyclic ring structure; n is 0, 1, or 2; and m is 0, 1, 2, or 3, where n+m=0, 1, 2, or 3.

[0021] The composition comprising silicon compounds having formula I and silicon precursor compounds having formula I according to the present invention is preferably substantially free of halide. The term "substantially free" as used herein means less than 5 ppm (by mass) measured by ion chromatography (IC) or inductively coupled plasma mass spectrometry (ICP-MS), preferably less than 3 ppm measured by IC or ICP-MS, more preferably less than 1 ppm measured by IC or ICP-MS, and most preferably 0 ppm measured by IC or ICP-MS, when referring to halide ions (or halides), such as chloride (i.e., chloride-containing species, such as HCl or silicon compounds having at least one Si-Cl bond) and fluoride, bromide and iodide. Chloride is known to act as a decomposition catalyst for silicon compounds having formula I. Significant levels of chloride in the final product may cause the decomposition of silicon precursor compounds. The gradual decomposition of silicon compounds may directly affect the deposition process of films, making it difficult for semiconductor manufacturers to meet film specifications. Furthermore, shelf life or stability is adversely affected by the higher decomposition rate of silicon compounds having formula I, thereby making it difficult to guarantee a shelf life of 1-2 years. Thus, the accelerated decomposition of silicon compounds having formula I raises safety and performance concerns regarding their formation of flammable and / or pyrophoric gaseous by-products. Silicon compounds having formula I preferably contain metal ions, e.g., Li + , Na + , K + , Mg 2+ , Ca 2+ , Al 3+ , Fe 2+ , Fe 2+ , Fe 3+ , Ni 2+ , Cr 3+As used herein, the term "substantially free" means less than 5 ppm (by weight), preferably less than 3 ppm, more preferably less than 1 ppm, and most preferably less than 0.1 ppm, as measured by ICP-MS, when referring to Li, Na, K, Mg, Ca, Al, Fe, Ni, Cr. In some embodiments, the silicon compound having formula I is free of metal ions, e.g., Li + , Na + , K + , Mg 2+ , Ca 2+ , Al 3+ , Fe 2+ , Fe 2+ , Fe 3+ , Ni 2+ , Cr 3+ Free of. The term "free" as used herein means less than 1 ppm, preferably 0.1 ppm (by weight), as measured by ICP-MS or other analytical methods for measuring metals, when it relates to Li, Na, K, Mg, Ca, Al, Fe, Ni, Cr, precious metals, such as volatile Ru or Pt complexes from ruthenium or platinum catalysts used in synthesis.Furthermore, the silicon compound having formula I, when used as a precursor for depositing silicon-containing films, preferably has a purity of 98% by weight or more, more preferably 99% by weight or more, as measured by GC.

[0022] Another embodiment of the invention includes a method for depositing silicon oxide films having less than 1 atomic % carbon and / or nitrogen content using at least one silicon compound having formula I. According to a preferred embodiment, one silicon precursor is tetraisocyanatosilane (TiCS), which is deposited in the presence of a catalyst and an oxygen source, such as water. In this and other embodiments, the catalyst is a Lewis base, such as pyridine, piperazine, ammonia, or other organic amines, such as primary amines HNR. 2 , secondary amine HNR 2 R 3 , or a tertiary amine R 1 NR 2 R 3 , where R 1-3is as defined above, and R 1-3 is not hydrogen. Examples of organic amines include, but are not limited to, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, tri-n-propylamine, and tri-iso-propylamine. In some embodiments, the catalyst is fed into the reactor using a separate gas line, while in other embodiments, the catalyst is premixed with an oxygen source at a catalyst concentration ranging from 0.001 to 99.99 wt % and then fed into the reactor by direct liquid injection (DLI) or bubbling or steam aspiration, preferably DLI. The amount of oxygen source, e.g., water, in the catalyst ranges from 0.001 wt % to 99.99 wt %.

[0023] In one embodiment of the method described herein, the silicon-containing film is deposited using a thermal AlD or cyclic CVD process. In this embodiment, the method includes the steps of: a. placing the substrate in a reactor and heating the reactor to one or more temperatures ranging from about 20° C. to about 600° C.; b. introducing into a reactor a precursor comprising at least one silicon compound having at least one isocyanate group, preferably a compound according to formula I above, and optionally introducing into the reactor a catalyst; c. purging the reactor with a purge gas; d. providing an oxygen source and optionally a catalyst into the reactor to react with the surface to form an as-deposited film, the catalyst comprising a Lewis base; and e. purging the reactor with a purge gas; wherein steps b to e are repeated until a desired thickness of silicon oxide or carbon-doped silicon oxide is deposited as a silicon-containing film on the substrate; Optionally, annealing the as-deposited film at one or more temperatures higher than said heating temperature, wherein said annealing step is carried out at one or more temperatures in the range of about 400° C. to about 1000° C.; Optionally, subjecting the as-deposited film to a post-deposition treatment with an oxygen source at one or more temperatures ranging from about room temperature to about 1000° C., or from about 100° C. to 400° C., to provide a film having a higher density; Optionally, exposing the as-deposited film to a UV source; and Optionally, post-deposition treating the treated film with a noble gas or hydrogen-containing plasma. The oxygen source is a mild oxidizer, i.e., it is not capable of oxidizing the substrate, e.g., amorphous carbon, and is selected from the group consisting of water, hydrogen peroxide, and combinations thereof.

[0024] In one specific embodiment for the deposition of silicon-containing films, e.g., pure silicon oxide having less than 1 atomic % of either carbon or nitrogen, or both, the silicon compound is tetraisocyanate silane containing 100 ppm or less of chloride. In another specific embodiment for the deposition of silicon-containing films, e.g., silicon oxide having less than 1 atomic % of either carbon or nitrogen, or both, the silicon compound is Si(NR 2 R 3 ) m (NCO) 4-m-n (wherein in formula I, n=0, m=1, 2.3). Exemplary compounds include, but are not limited to, dimethylaminotriisocyanatesilane, diethylaminotriisocyanatesilane, ethylmethylaminotriisocyanatesilane, di-iso-propylaminotriisocyanatesilane, di-sec-butylaminotriisocyanatesilane, and pyrrolidinotriisocyanatesilane. It is believed that silicon compounds having both organic amino groups and isocyanate groups are more reactive than those having only isocyanate groups, thus allowing more silicon fragments to be fixed, which gives a higher growth rate. Furthermore, in another embodiment for the deposition of silicon-containing films, such as carbon-doped silicon oxide having a carbon content of about 1 atomic % to 15 atomic %, the silicon compound is MeSi(NR 2 R 3 ) m (NCO)4-m-n (wherein in formula I, n=1, m=0, 1, 2).

[0025] In certain embodiments, one or more steps are carried out in the presence of a catalyst. In this or other embodiments, the catalyst is a Lewis base, such as pyridine, piperazine, ammonia, or other organic amines, such as primary amines HNR 2 , secondary amine HNR 2 R 3 , or a tertiary amine R 1 NR 2 R 3 is selected from, where R 1-3 is as above, and R 1-3 is not hydrogen. Examples of organic amines include, but are not limited to, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, tri-n-propylamine, tri-iso-propylamine. In some embodiments, the catalyst is fed into the reactor using a separate gas line, while in other embodiments, the catalyst is premixed with the oxygen source at a catalyst concentration ranging from 0.01 ppm to 99.9 wt % and then fed into the reactor by direct liquid injection (DLI) or bubbling or steam aspiration, preferably DLI.

[0026] In the above formula and throughout this specification, the term "alkyl" refers to a straight chain or branched functional group having 1-10 or 1-4 carbon atoms. Exemplary straight chain alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, and hexyl. Exemplary branched alkyl groups include, but are not limited to, iso-propyl, iso-butyl, sec-butyl, tert-butyl, iso-pentyl, tert-pentyl, and iso-hexyl. In certain embodiments, the alkyl groups can have one or more functional groups attached thereto, such as, but not limited to, alkoxy groups, dialkylamino groups, or combinations thereof. In other embodiments, the alkyl groups do not have one or more functional groups attached thereto.

[0027] In the above formula and throughout this specification, the term "cyclic alkyl" refers to a cyclic functional group having 3 to 10 or 4 to 10 carbon atoms. Exemplary cyclic alkyl groups include, but are not limited to, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups.

[0028] In the above formula and throughout this specification, the term "alkenyl group" means a group having one or more carbon-carbon double bonds and having 2 to 10 or 2 to 6 carbon atoms. Exemplary alkenyl groups include, but are not limited to, vinyl or allyl groups.

[0029] In the above formula and throughout this specification, the term "alkynyl group" means a group having one or more carbon-carbon triple bonds and having 2 to 10 or 2 to 6 carbon atoms.

[0030] In the above formula and throughout this specification, the term "aryl" refers to an aromatic cyclic functional group having 4 to 10 carbon atoms, 5 to 10 carbon atoms, or 6 to 10 carbon atoms. Exemplary aryl groups include, but are not limited to, phenyl, benzyl, chlorobenzyl, tolyl, o-xylyl, 1,2,3-triazolyl, pyrrolyl, and furanyl, pyridazinyl, pyrimidinyl, pyrazinyl, and imidazolyl.

[0031] As mentioned above, 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 a variety of materials well known in the art, such as silicon, silicon oxide, silicon nitride, amorphous carbon, silicon oxycarbide, silicon oxynitride, silicon carbide, germanium, germanium-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 cover the semiconductor substrate, can be multiple layers of various materials, and can be partially etched to expose layers of underlying materials. The surface can also have a photoresist material thereon that is exposed in a pattern and developed to partially cover the substrate. In certain embodiments, the semiconductor substrate has at least one surface feature selected from the group consisting of holes, vias, trenches, and combinations thereof.

[0032] The deposition method used to form the 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, cyclic chemical vapor deposition or atomic layer deposition processes. The term "cyclic chemical vapor deposition process" as used herein 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 a desired deposition. The term "atomic layer deposition process" as used herein 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 of various compositions on a substrate. Although the precursors, reagents and sources used herein are often described as "gaseous", it is understood that the precursors can be either liquids or solids that are transported into the reactor by direct evaporation, bubbling or sublimation, with or without an inert gas. In some cases, the evaporated precursors can be passed through a plasma generator.

[0033] In one embodiment, the silicon-containing film is deposited using ALD process. In another embodiment, the silicon-containing film is deposited using CCVD process. In a further embodiment, the silicon-containing film is deposited using thermal ALD process. As used herein, "reactor" includes, but is not limited to, reaction chamber or deposition chamber.

[0034] In certain embodiments, the method disclosed herein avoids pre-reaction of precursors by using ALD or CCVD methods that separate precursors before and / or during introduction into the reactor. In this regard, deposition techniques, such as ALD or CCVD processes, are used to deposit silicon-containing films. In one embodiment, the film is deposited by ALD process by exposing the substrate surface to one or more silicon-containing precursors, oxygen sources, nitrogen-containing sources, or other precursors or reagents in a typical single-wafer ALD reactor, semi-batch ALD reactor, or batch furnace ALD reactor. The growth of the film proceeds by self-limiting control of surface reactions, pulse lengths of each precursor or reagent, and deposition temperature. However, once the substrate surface is saturated, the growth of the film stops. In other embodiments, each reactant, e.g., silicon and reactive gas, is exposed to the substrate by moving or rotating the substrate to different zones of the reactor, and each zone is separated by a curtain of inert gas, i.e., a spatial ALD reactor or a roll-to-roll ALD reactor.

[0035] Depending on the deposition method, in certain embodiments, the silicon precursors described herein and optionally other silicon-containing precursors are 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 are introduced into the reactor for a predetermined period of time. In certain embodiments, this period of time ranges from about 0.001 to about 500 seconds.

[0036] In certain embodiments, the silicon-containing films deposited using the methods described herein are formed in the presence of oxygen using an oxygen source, an oxygen-containing reagent or precursor. The oxygen source can be introduced into the reactor in the form of at least one oxygen source and / or can be present concomitantly in other precursors used in the deposition process. Suitable oxygen source gases can include, for example, water (H2O) (e.g., deionized water, pure water, distilled water, water vapor, water vapor plasma, oxygenated water, compositions containing water, and other organic liquids, such as organic amines as catalysts, hydrogen peroxide, and combinations thereof. In certain embodiments, the oxygen source comprises an oxygen source gas introduced into the reactor at a flow rate ranging from about 1 to about 2000 square cubic centimeters (sccm) or from about 1 to about 1000 sccm. The oxygen source can be introduced for a time ranging from about 0.1 to about 100 seconds.

[0037] In embodiments in which the film is deposited by an ALD or cyclic CVD process, the precursor pulse can have a pulse duration of greater than 0.01 seconds and the oxygen source can have a pulse duration of less than 0.01 seconds, while the water pulse can have a pulse duration of less than 0.01 seconds.

[0038] In certain embodiments, the oxygen source is a continuous flow into the reactor, while the precursor pulse and plasma are introduced sequentially. The precursor pulse has a pulse duration of greater than 0.01 seconds, while the plasma duration can range from 0.01 to 100 seconds.

[0039] In certain embodiments, one or more steps are carried out in the presence of a catalyst; in this or other embodiments, the catalyst is selected from a Lewis base, such as pyridine, piperazine, ammonia, or other organic amines.

[0040] The deposition methods disclosed herein can include one or more purge gases. A purge gas is an inert gas that is used to purge unconsumed reactants and / or reaction by-products and does not react with the precursors. Exemplary purge gases include, but are not limited to, argon (Ar), nitrogen (N2), helium (He), neon, hydrogen (H2), and combinations thereof. In certain embodiments, a purge gas, such as Ar, is delivered into the reactor at a flow rate ranging from about 10 to about 2000 sccm for about 0.1 to 1000 seconds, thereby purging unreacted materials and any by-products that may remain in the reactor.

[0041] Each step of supplying the silicon precursor, oxygen source, nitrogen-containing source, and / or other precursors, source gases, and / or reagents can be performed by varying the time for which they are supplied to vary the stoichiometry of the resulting film.

[0042] In certain embodiments, a second RF frequency source can be used to change the plasma characteristics at the substrate surface. In embodiments in which deposition involves a plasma, the plasma generation process can include a direct plasma generation process in which the plasma is generated directly in the reactor, or a remote plasma generation process in which the plasma is generated outside the reactor and fed into the reactor.

[0043] Silicon precursors and / or other silicon-containing precursors can be delivered to a reaction chamber, such as a CVD or ALD reactor, in a variety of ways. In one embodiment, a liquid delivery system can be used. In another embodiment, a combined liquid delivery and evaporation process device, such as a turbo evaporator manufactured by MSP Corporation of Shoreview, Minnesota, can be used to ensure that low volatility materials are delivered volumetrically, which results in reproducible transport and deposition without precursor thermal decomposition. In liquid delivery formulations, the precursors described herein can be delivered in pure liquid form or can be used in solvent formulations or compositions containing same. Thus, in certain embodiments, the precursor formulation can include a solvent component with suitable properties as desired and advantageous for a given end use to form a film on a substrate.

[0044] In this embodiment or other embodiments, it is understood that the steps of the method described herein can be performed in various orders, and can be performed sequentially or simultaneously (e.g., between at least some of the other steps), and combinations thereof. Each step of supplying the precursor and the nitrogen-containing source gas can be performed by varying the duration of time for which they are supplied to change the stoichiometric composition of the resulting silicon-containing film.

[0045] In yet further aspects of the methods described herein, the film or as-deposited film is subjected to a treatment step. The treatment step can be performed during at least a portion of the deposition step, after the deposition step, and combinations thereof. Exemplary treatment steps include, but are not limited to, high temperature thermal annealing treatment, plasma treatment, ultraviolet (UV) radiation treatment, laser, electron beam treatment, and combinations thereof, which affect one or more properties of the film. The film deposited with the silicon precursor described herein has improved properties, such as, but not limited to, a wet etch rate lower than the wet etch rate of the film before the treatment step, or a density higher than the density before the treatment step, when compared to a film deposited with a silicon precursor previously disclosed under the same conditions. In one particular aspect, the as-deposited film is intermittently treated during the deposition process. These intermittent or during-deposition treatments can be performed, for example, after each ALD cycle, after a certain number of ALD cycles, such as, but not limited to, every two (2) ALD cycles, five (5) ALD cycles, or every ten (10) or eleven or more ALD cycles.

[0046] In embodiments where the silicon-containing film is subjected to a high temperature annealing step, the annealing temperature is at least 100° C. or higher than 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 process can be performed in a vacuum (less than 760 Torr) in an inert or oxidizing atmosphere.

[0047] In embodiments in which the silicon-containing film is treated with a UV treatment, the film is exposed to broadband UV, or a UV source having a wavelength in the range of about 150 nanometers (nm) to about 400 nm. In one particular embodiment, the as-deposited film is exposed to UV in a chamber different from the deposition chamber after the desired film thickness is reached.

[0048] In the embodiment where the silicon-containing film is treated with plasma, the plasma source is selected from the group consisting of nitrogen plasma, plasma containing nitrogen and helium, plasma containing nitrogen and argon, ammonia plasma, plasma containing ammonia and helium, plasma containing ammonia and argon, helium plasma, argon plasma, neon plasma, hydrogen plasma, plasma containing hydrogen and helium, plasma containing hydrogen and argon, organic amine plasma, organic diamine plasma, and combinations thereof.In one particular embodiment, the plasma comprises an inert gas selected from the group consisting of helium, neon, argon, krypton, and combinations thereof.

[0049] In another embodiment, the silicon-containing film has the general formula R 1 R 2 NSiR 3 R 4 R 5 wherein R is a silane having an alkyl group; 1-3 is as defined above, and R 4-5 are independently hydrogen, a linear C1-C6 alkyl group, or a branched C3-C6 alkyl group. Examples include dimethylaminotrimethylsilane, diethylaminotrimethylsilane, dimethylaminotriethylsilane, diisopropylaminotrimethylsilane, diisopropylaminosilane, and disecbutylaminosilane. The present invention includes the following aspects. (1) A method for depositing a silicon-containing film on a substrate, comprising the steps of: a) providing a substrate in a reactor; b) introducing into the reactor at least one silicon compound having at least one isocyanate group, optionally together with a first catalyst, having the following formula I: R 1 n Si(NR 2 R 3 ) m (NCO) 4-m-n In the formula, R 1is hydrogen, a straight chain C1-C6 alkyl group, a branched C3-6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 aryl groups, R 2 and R 3 is hydrogen, a C1-C6 linear alkyl group, a branched C3-C6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 aryl groups, which may or may not be joined to form a cyclic ring structure, n is 0, 1 or 2, and m is 0, 1, 2 or 3, where n+m=0, 1, 2 or 3; c) purging the reactor with a purge gas; d) introducing into the reactor an oxygen source and, optionally, a second catalyst, which may be the same as or different from the first catalyst, to react with the at least one silicon compound and produce the silicon oxide film; and e) purging the reactor with a purge gas; 1. A method comprising: Steps b through e are repeated until a desired thickness of the silicon oxide film is deposited on the substrate, the method being carried out at one or more temperatures ranging from 20 to 600° C. and at one or more pressures ranging from 50 milliTorr (mT) to 760 Torr. method. (2) The method of (1), wherein the oxygen source is selected from the group consisting of water vapor, hydrogen peroxide, and combinations thereof. (3) The method according to (1), wherein the silicon-containing film is a silicon oxide film or a carbon-doped silicon oxide film. (4) The first and second catalysts are each selected from the group consisting of pyridine, piperazine, ammonia, and a primary amine HNR 2 , secondary amine HNR 2 R 3 , and tertiary amine R 1 NR 2 R 3where R 1-3 is as defined in (1), and R 1-3 The method according to (1), wherein is not hydrogen. (5) The method according to (4), wherein at least one of the first and second catalysts is selected from the group consisting of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, tri-n-propylamine, and tri-iso-propylamine. (6) The method according to (1), wherein the at least one silicon compound is selected from formula I, where n=0. (7) The method according to (6), wherein the at least one silicon compound is selected from the group consisting of dimethylaminotriisocyanate silane, diethylaminotriisocyanate silane, di-iso-propylaminotriisocyanate silane, di-sec-butylaminotriisocyanate silane, pyrrolidinotriisocyanate silane and tetraisocyanate silane. (8) The at least one silicon compound is R 1 is methyl and has formula I, n=1. (9) A silicon oxide film produced by the method of formula I. (10) A composition for depositing a silicon-containing film using a deposition process, comprising at least one silicon precursor having a structure represented by Formula I: R 1 n Si(NR 2 R 3 ) m (NCO) 4-m-n In the formula, R 1 is hydrogen, a straight chain C1-C6 alkyl group, a branched C3-6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 aryl groups, R 2 and R 3 is hydrogen, a C1-C6 linear alkyl group, a branched C3-C6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C10 aryl groups, which may or may not be joined to form a cyclic ring structure, n is 0, 1 or 2, and m is 0, 1, 2 or 3, where n+m=0, 1, 2 or 3; A composition comprising: (11) The composition according to (10), wherein the composition is substantially free of one or more impurities selected from the group consisting of halide compounds, metal ions, metals, and combinations thereof. (12) The composition according to (11), wherein the halide compound comprises a chloride-containing species. (13) The composition according to (12), wherein the chloride concentration is less than 50 ppm as measured by IC or ICP-MS. (14) The composition according to (13), wherein the chloride concentration is less than 10 ppm as measured by IC or ICP-MS. (15) The composition according to (14), wherein the chloride concentration is less than 5 ppm as measured by IC or ICP-MS. (16) The composition according to (10), wherein n = 0. (17) The composition according to (10), wherein the silane is selected from the group consisting of dimethylaminotriisocyanate silane, diethylaminotriisocyanate silane, di-iso-propylaminotriisocyanate silane, di-sec-butylaminotriisocyanate silane, pyrrolidinotriisocyanate silane and tetraisocyanate silane. (18)R 1 is methyl and n=1. (19) An apparatus for depositing a silicon-containing film using a deposition process, comprising: a reactor in which the deposition process takes place; A source for supplying the composition according to (10) to the reactor; a catalyst source in fluid communication with the reactor; and a source of oxygen in fluid communication with the reactor or the source of catalyst; comprising The catalyst is selected from the group consisting of pyridine, piperazine, ammonia, and primary amines HNR 2 , secondary amine HNR 2 R 3 , and tertiary amine R 1 NR 2 R 3 where R 1-3 is a linear C1-C6 alkyl group, a branched C3-6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 are independently selected from aryl groups, and may or may not be joined to form a cyclic ring structure; Device. (20) An apparatus for depositing a silicon-containing film using a deposition process, comprising: a reactor in which the deposition process takes place; A source for supplying the composition according to (10) to the reactor; and a mixture of an oxygen source and a catalyst source in a vessel in fluid communication with the reactor; comprising The catalyst is selected from the group consisting of pyridine, piperazine, ammonia, and primary amines HNR 2 , secondary amine HNR 2 R 3 , and tertiary amine R 1 NR 2 R 3 where R 1-3 is a linear C1-C6 alkyl group, a branched C3-6 alkyl group, a C3-C6 cyclic alkyl group, a C2-C6 alkenyl group, a C3-C6 alkynyl group, and a C4-C 10 are independently selected from aryl groups, and may or may not be joined to form a cyclic ring structure; Device. (21) The apparatus according to (19), wherein the oxygen source is selected from the group consisting of water vapor, hydrogen peroxide, and combinations thereof. (22) The apparatus according to (20), wherein the oxygen source is selected from the group consisting of water vapor, hydrogen peroxide, and combinations thereof. EXAMPLES

[0050] Common Film Deposition Examples The deposition of the film was carried out in a laboratory-scale thermal atomic layer deposition (ALD) reactor using a silicon compound having at least one isocyanate group and an oxygen source. Tetraisocyanatosilane (TiCS) was used as the silicon precursor and water, triethylamine (TEA), or a combination of the two, as the oxygen source. Optionally, the water was mixed with triethylamine (TEA) before being introduced into the reactor. The vessel with TiCS was heated to 50° C., while the oxygen source was supplied at room temperature. Both TiCS and the oxygen source were supplied using steam aspirate. The ALD cycle steps and process conditions are given in Table 1 below. [Table 1] Steps 4-9 are repeated multiple times until the desired thickness is obtained. Film thickness was measured using a Filmtek 3000 PAR SE ellipsometer from Scientific Computing International (SCI).

[0051] Comparative Example 1. Deposition of silicon-containing films using tetraisocyanate silane (TiCS) and water

[0052] Deposition of silicon-containing films was carried out at substrate temperatures between 50 and 150° C. using the conditions shown in Table 1, using TICS as the silicon precursor and water as the oxygen source. The substrate used was a piece of silicon with native oxide. The TiCS flow was set for 180 seconds and the water flow for 120 seconds. The ALD process was repeated 100 times. The film growth per cycle (GPC), which is the deposited film thickness after cycling steps 4-9 in Table I at different temperatures, is listed in Table II. [Table 2] Film growth is relatively high at 50° C., and at higher temperatures growth is very little or absent.

[0053] Comparative Example 2. Deposition of silicon-containing films using TiCS and triethylamine

[0054] Deposition of silicon-containing films was carried out using the above process with TiCS as silicon precursor and triethylamine as catalyst at substrate temperatures above 150°C. The water content in triethylamine was 80 ppm. The substrate used was a piece of silicon with native oxide. The flow of TiCS was set for 120 seconds and the flow of triethylamine for 120 seconds. The ALD process was repeated 100 times. A film thickness of 31 Å was obtained giving a GPC of 0.31 Å / cycle.

[0055] Example 1. Deposition of silicon-containing films using TiCS and water / triethylamine Deposition of silicon-containing films was carried out at a substrate temperature of 150° C. using TiCS as the silicon precursor and water as the oxygen source, where the water was mixed with the catalyst. The substrate used was a piece of silicon with native oxide. Triethylamine was selected as the catalyst. Water at a concentration of 1 wt % was mixed with dry triethylamine in a vessel prior to deposition. Deposition was carried out according to the steps listed in Table 1. The ALD process was repeated 100 times to give a film thickness of 90 Å and a GPC of 0.90 Å / cycle, indicating that the combination of water and triethylamine as a catalyst significantly improves the GPC.

[0056] Example 2. Deposition of silicon-containing films using TiCS and water / triethylamine

[0057] Deposition of silicon-containing films was carried out using TiCS as silicon precursor and water as oxygen source, where water was mixed with a catalyst. Triethylamine was selected as the catalyst. In this experiment, water with concentrations ranging from 80 ppm to 10 wt.% was mixed in a container of triethylamine prior to deposition. The substrate used was a piece of silicon with native oxide. The deposition temperature was set at 150°C. The flow of TiCS was set for 120 seconds and the flow of triethylamine / water solution was set for 120 seconds. The ALD process was repeated 100 times to obtain the desired thickness for measurement. The film thickness at various water concentrations is summarized in Table III. [Table 3] Table III clearly shows that at higher water concentrations (greater than 80 ppm), the GPC film is higher (i.e., higher film GPC). At a water concentration of 80 ppm in triethylamine, the GPC is 0.3 Å / cycle, while higher water concentrations, i.e., greater than 0.1 wt. % in triethylamine, give silicon-containing films with GPC of about 0.8 Å / cycle.

Claims

1. A composition for depositing a silicon-containing film using a deposition process, comprising at least one silicon precursor having a structure represented by Formula I: 【Chemistry 1】 In the formula, R １ is hydrogen, linear C １ ~C ６ Alkyl group, branched C ３ ~ ６ Alkyl group, C ３ ~C ６ Cyclic alkyl group, C ２ ~C ６ Alkenyl group, C ３ ~C ６ Alkynyl groups, and C ４ ~C １０ aryl groups; R ２ and R ３ is hydrogen, C １ ~C ６ Straight chain alkyl group, branched C ３ ~C ６ Alkyl group, C ３ ~C ６ Cyclic alkyl group, C ２ ~C ６ Alkenyl group, C ３ ~C ６ Alkynyl groups, and C ４ ~C １０ aryl groups, which may or may not be joined to form a cyclic ring structure, n is 0, 1 or 2, and m is 0, 1, 2 or 3, where n+m=0, 1, 2 or 3; comprising the composition is substantially free of one or more impurities selected from the group consisting of halide compounds, metal ions, metals, and combinations thereof; the halide compound comprises a chloride-containing species; and the chloride concentration is less than 50 ppm as measured by IC or ICP-MS; composition.

2. 10. The composition of claim 1, wherein the chloride concentration is less than 10 ppm as measured by IC or ICP-MS.

3. 2. The composition of claim 1, wherein the chloride concentration is less than 5 ppm as measured by IC or ICP-MS.

4. The composition of claim 1 , wherein n=0.

5. The composition of claim 1, wherein the triisocyanate silane is selected from the group consisting of dimethylaminotriisocyanate silane, diethylaminotriisocyanate silane, di-iso-propylaminotriisocyanate silane, di-sec-butylaminotriisocyanate silane, pyrrolidinotriisocyanate silane, and tetraisocyanate silane.

6. R １ The composition of claim 1 , wherein is methyl and n=1.

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