SHORT INORGANIC TRISILYLAMINE-BASED POLYSILAZANES FOR THIN FILM DEPOSITION

Abstract

Disclosed are Si—C free and volatile silazane precursors for high purity thin film deposition.

Claims

1. A silicon-containing film forming composition comprising a precursor selected from the group consisting of: (a) [(SiR.sub.3).sub.2NSiH.sub.2].sub.m—NH.sub.2-m—C≡N, with m=1 or 2; (b) [(SiR.sub.3).sub.2NSiH.sub.2].sub.n-NL.sub.3-n, with n=2 or 3; (c) (SiH.sub.3).sub.2NSiH.sub.2—O—SiH.sub.2N(SiH.sub.3).sub.2; and (d) (SiR′.sub.3).sub.2N—SiH.sub.2—N(SiR′.sub.3).sub.2; wherein each R is independently selected from H, a dialkylamino group having the formula —NR.sup.1R.sup.2, or an amidinate, Each R′ is independently selected from H, a dialkylamino group having the formula —NR.sup.1R.sup.2, or an amidinate, with the provision that all R′ are not H, R.sup.1 and R.sup.2 are independently selected from H or a C1-C12 hydrocarbyl group, with the provision that R.sup.1 and R.sup.2 cannot be simultaneously equal to H, and that if R.sup.1 is H, then R.sup.2 is a C.sub.2-C12 hydrocarbyl group, and NR.sup.1R.sup.2 may together form an N-containing heterocyclic ligand, and L is selected from H or a C.sub.1-C.sub.6 hydrocarbyl group.

2. The silicon-containing film forming composition of claim 1, wherein the precursor is (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NR.sup.1R.sup.2), (SiH.sub.3).sub.2NSiH.sub.2—O—SiH.sub.2N(SiH.sub.3).sub.2, [(SiH.sub.3).sub.2NSiH.sub.2]—NH—C≡N, or [(SiH.sub.3).sub.2NSiH.sub.2].sub.2N—C≡N.

3. The silicon-containing film forming composition of claim 1, wherein the precursor is [(SiH.sub.3).sub.2NSiH.sub.2].sub.2NH or [(SiH.sub.3).sub.2NSiH.sub.2].sub.3N.

4. The silicon-containing film forming composition of claim 1, wherein the precursor is (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NMe.sub.2), (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NEt.sub.2), (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NEtMe), (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NiPr.sub.2), (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NtBu.sub.2), (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NnBu.sub.2), (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NsecBu.sub.2), or (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2NHtBu).

5. A method of deposit a silicon-containing film on a substrate by a chemical vapor deposition method, the method comprising introducing into a reactor containing a substrate a vapor including the Si-containing film forming composition of claim 1; depositing at least part of the precursor onto the substrate to form the silicon-containing film on the substrate using a chemical vapor deposition process.

6. The method of claim 5, wherein the chemical vapor deposition method is an atomic layer deposition process or a plasma enhanced atomic layer deposition process.

7. The method of claim 5, wherein the silicon-containing film is a silicon oxide film.

8. The method of claim 5, wherein the silicon-containing film is a silicon nitride film.

9. The method of claim 5, wherein the substrate is a silicon wafer.

10. The method of claim 5, wherein the substrate is glass.

11. The method of claim 5, wherein the substrate is an organic material.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0132] For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying FIGURE wherein:

[0133] FIGURE is a Gas Chromatographic spectrum of the perhydropolysilazane oil of the Example.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0134] Silicon-containing film forming compositions are disclosed comprising short chain (Si ranging from 3 to 10) oligosilazanes having at least a trisilylamine backbone selected from the family of:

[0135] (1) [(SiR.sub.3).sub.2NSiH.sub.2].sub.n-NL.sub.3-n, with n=2 or 3

[0136] (2) (SiH.sub.3).sub.2NSiH.sub.2—O—SiH.sub.2N(SiH.sub.3).sub.2

[0137] (3) (SiR′.sub.3).sub.2N—SiH.sub.2—N(SiR′.sub.3).sub.2

[0138] (4) [(SiR.sub.3).sub.2NSiH.sub.2].sub.m—NH.sub.2-m—C≡N, with m=1 or 2

in which [0139] each R is independently selected from H, a dialkylamino group having the formula —NR.sup.1R.sup.2, or an amidinate; [0140] each R′ is independently selected from H, a dialkylamino group having the formula —NR.sup.1R.sup.2, or an amidinate, with the provision that all R′ are not H [0141] R.sup.1 and R.sup.2 are independently selected from H or a C1-C12 hydrocarbyl group with the provision that R.sup.1 and R.sup.2 cannot be simultaneously equal to H, and that if R.sup.1 is H, then R.sup.2 is a C.sub.2 hydrocarbyl group or larger, [0142] NR.sup.1R.sup.2 may form a N-containing heterocyclic ligand, and [0143] L is selected from H or a C.sub.1-C.sub.6 hydrocarbyl group

[0144] Preferred embodiments of the above compounds include: [0145] A molecule of Family (1) in which all R═H, L=H and n=2: [(SiH.sub.3).sub.2NSiH.sub.2].sub.2NH [0146] A molecule of Family (1) in which all R═H, L=a C.sub.1-C.sub.6 hydrocarbyl group and n=2: [(SiH.sub.3).sub.2NSiH.sub.2].sub.2NL [0147] The above molecule in which L is selected from methyl, ethyl, isopropyl, n-propyl, tertiarybutyl, sec-butyl, n-butyl, hexyl, vinyl, allyl, [0148] A molecule of Family (1) in which all R═H and n=3: [(SiH.sub.3).sub.2NSiH.sub.2].sub.3N [0149] A molecule of Family (3) in which all except one R′═H and one R′ is NR.sup.1R.sup.2, as defined above: (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3)(SiH.sub.2N(R.sup.1R.sup.2)) [0150] The above molecule in which R.sup.1═R.sup.2=Et [0151] The above molecule in which R.sup.1═R.sup.2=iPr [0152] The above molecule in which R.sup.1═R.sup.2=Me [0153] The above molecule in which R.sup.1=Me and R.sup.2=Et [0154] The above molecule in which R.sup.1═R.sup.2=tBu [0155] The above molecule in which R.sup.1═R.sup.2=n-Bu [0156] The above molecule in which R.sup.1═R.sup.2=secBu [0157] The above molecule in which R.sup.1═H and R.sup.2=tBu [0158] The above molecule in which NR.sup.1R.sup.2 is pyrrole, pyrrolidine, piperidine, imidazole or azidrine [0159] The molecule of Family (4) being [(SiH.sub.3).sub.2NSiH.sub.2].sub.2N—C≡N [0160] The molecule of Family (4) being [(SiH.sub.3).sub.2NSiH.sub.2]—NH—C≡N

[0161] Furthermore, the invention comprises the synthesis of compounds of families (1), (2), (3) and (4) from the following synthesis processes:

Family 1

[0162] (1) From the reaction of (SiR.sub.3).sub.2NSiH.sub.2—X, X being selected from Cl, Br, I, SCN or NCO, with a primary amine NH.sub.2L according to the reaction:

n(SiR.sub.3).sub.2NSiH.sub.2—X+NH.sub.2L.fwdarw.[(SiR.sub.3).sub.2NSiH.sub.2].sub.n-NL.sub.3-n+(n+1)NH.sub.3LX (salt) [0163] The reaction being preferably carried in an anhydrous and aprotic solvent or solvent mixture, such as but not limited to a C.sub.3-C.sub.24 hydrocarbon solvent, toluene, benzene, diethylether, acetonitrile, or tetrahydrofuran (THF). [0164] The reaction being carried at a temperature between −40° C. and 100° C., preferably at room temperature. [0165] Optionally, the formed salt being filtered from the reaction mixture and the components of the remaining liquid composition being separated by distillation. [0166] Optionally, the compound of family (1) being purified by distillation to reach an assay of >98%, more preferably or >99%, and even more preferably >99.5%, which is typical of semiconductor grade precursors [0167] Optionally, the product of family (1) may be further treated to reduce the content of dissolved NH.sub.3LX salts, for instance by exposing the product to a solid adsorbent such as activated carbon, dried Amberlyst resin or other such ion exchange resin. [0168] Optionally, the product may be filtered to reach specifications that are typical of products used in the semiconductor industry [0169] the (SiR.sub.3).sub.2NSiH.sub.2—X reactant may be synthesized as disclosed in co-pending US Pat. App. Pub. No. 2015/0376211, more particularly by SnX.sub.4+N(SiR.sub.3).sub.3.fwdarw.N(SiR.sub.3).sub.2(SiR.sub.2X)+SnX.sub.2↓+HXI, wherein X is Cl, Br, or I (see J. Chem. Soc. Dalton Trans. 1975, p. 1624). Alternatively, dihalosilane [SiR.sub.2X.sub.2, wherein X is Cl, Br, or I] and monohalosilane [SiR.sub.3X, wherein X is Cl, Br, or I] may be introduced continuously in the gas phase in a 1/20 to 1/4 ratio and at room temperature with 400 sccm of NH.sub.3 in a flow-through tubular reactor as described by Miller in U.S. Pat. No. 8,669,387. The reaction of NH.sub.3 with 2 equivalents of monohalosilane produces mostly disilylamine (DSA). DSA then reacts with the dihalosilane to form (SiH.sub.3).sub.2—N—SiH.sub.2X and HX, wherein X is Cl, Br, or I. One of ordinary skill in the art would recognize that the reaction may take place in one or two steps (first forming DSA from the monohalosilane and NH.sub.3 and second adding dihalosilane) or in one step (combining the monohalosilane, dichlorosilane, and NH.sub.3 in one step). [0170] (2) From the direct dehydrogenative coupling reaction of (SiR.sub.3).sub.2NSiH.sub.3 with NH.sub.2L in the presence of a catalyst, as described in U.S. Pat. App. Pub. No. 2015/0094470, according to the reaction:

n(SiR.sub.3).sub.2NSiH.sub.3+NH.sub.2L.fwdarw.[(SiR.sub.3).sub.2NSiH.sub.2].sub.n-NL.sub.3-n+H.sub.2 [0171] The reaction being carried or neat or in an aprotic solvent such as, but not limited to a C3-C24 hydrocarbon solvent, toluene, benzene, diethylether, acetonitrile, or THF. [0172] The reaction being carried at a temperature between room temperature and 150° C., preferably at 30-60° C. [0173] Optionally, the catalyst being filtered from the reaction mixture and the components of the remaining liquid composition being separated by distillation. [0174] Optionally, the reaction mixture being treated with an agent to de-activate the catalyst, selected but not limited to a tertiary amine or a coordinant compound such as XNR.sub.4 (X═F, Cl, Br, I; R=alkyl), R—CN, R.sub.2S, or PR.sub.3. [0175] Optionally, the compound of family (1) being purified by distillation to reach an assay of >98%, more preferably or >99%, and even more preferably >99.5%, which is typical of semiconductor grade precursors [0176] Optionally, the product may be filtered to reach specifications that are typical of products used in the semiconductor industry.

Family 2

[0177] (3) From the reaction of (SiH.sub.3).sub.2NSiH.sub.2—X, wherein X is selected from Cl, Br, I, SCN NCO, or a NR.sup.1R.sup.2 group, and NR.sup.1R.sup.2 as defined above, with a H.sub.2O reactant according to the reaction:

2(SiH.sub.3).sub.2NSiH.sub.2—X+H.sub.2O.fwdarw.(SiH.sub.3).sub.2NSiH.sub.2—O—SiH.sub.2N(SiH.sub.3).sub.2+2HX [0178] The reaction being preferably carried in an anhydrous or aprotic solvent or solvent mixture, such as but not limited to a C.sub.3-C.sub.24 hydrocarbon solvent, toluene, benzene, diethylether, acetonitrile, or THF. [0179] The H.sub.2O being added slowly into the silane containing composition to maintain a constant excess of the silane moiety throughout the reaction [0180] The reaction being carried at a temperature between −40° C. and 100° C., preferably between −20° C. to room temperature. [0181] Optionally the water being added subsurface as vapor in a carrier gas [0182] Optionally the water being added diluted in a polar non protic solvent, typically from 1% to 50%, more preferably from 5% to 30% [0183] Optionally, and preferentially when X is a halogen, the reaction mixture comprising a halide scavenger, such as but not limited to pyridine, trialkylamine, in a quantity higher than the HX expected release on a molar basis. The halide scavenger may be used as the solvent. The reaction mixture may then be filtered to remove the HX-scavenger salt formed prior to the final product separation. [0184] Optionally, the compound of family (2) being purified by vacuum distillation to reach an assay of >98%, more preferably or >99%, and even more preferably >99.5%, which is typical of semiconductor grade precursors [0185] Optionally, the product of family (2) may be further treated to reduce the content of dissolved salts, for instance by exposing the product to a solid adsorbent such as activated carbon, dried Amberlyst resin or other such ion exchange resin. [0186] Optionally, the product may be filtered to reach specifications that are typical of products used in the semiconductor industry.

Family 3

[0187] Compounds of Family 3 are preferentially synthesized from the direct reaction of (SiH.sub.3).sub.2N—SiH.sub.2—N(SiH.sub.3).sub.2 (BDSASi) with an amine by dehydrogenative coupling, according to the same protocol as described in U.S. Pat. App. Pub. No. 2015/0094470.

SiH.sub.2[N(SiH.sub.3).sub.2].sub.2+nHNR.sup.1R.sup.2.fwdarw.SiH.sub.2[N(SiH.sub.3-x(NR.sup.1R.sup.2).sub.x][SiH.sub.3-y(NR.sup.1R.sup.2).sub.y]+(x+y)H.sub.2

with x=0 to 3, y=1 to 3 [0188] The reaction being carried neat or in an aprotic solvent such as, but not limited to a C3-C24 hydrocarbon solvent, toluene, benzene, diethylether, acetonitrile, or THF. [0189] The reaction being carried at a temperature between room temperature and 150° C., preferably at 30-60° C. [0190] Optionally, the catalyst being filtered from the reaction mixture and the components of the remaining liquid composition being separated by distillation. [0191] Optionally, the reaction mixture being treated with an agent to de-activate the catalyst, selected but not limited to a tertiary amine or a coordinant compound such as XNR.sub.4 (X═F, Cl, Br, I; R=alkyl), R—CN, R.sub.2S, PR.sub.3. [0192] Optionally, the compound of family (3) being purified by distillation to reach an assay of >98%, more preferably or >99%, and even more preferably >99.5%, which is typical of semiconductor grade precursors [0193] Optionally, the product may be filtered to reach specifications that are typical of products used in the semiconductor industry. [0194] the (SiR.sub.3).sub.2NSiH.sub.2—X reactant may be synthesized as disclosed in co-pending US Pat. App. App. No. 62/432,592, more particularly by mixing trisilylamine with a catalyst, such as B(C.sub.6F.sub.5).sub.3, BPh.sub.3, PdCl.sub.2, Co.sub.2(CO).sub.8, or Zeolite Y (H) Si:Al, without a NH.sub.3 reactant or heat.

Family 4

[0195] From the reaction of (SiR.sub.3).sub.2NSiH.sub.2—X, X being selected from Cl, Br, I, SCN or NCO, with the cyanamine group H.sub.2N—C≡N, according to the reaction:

m(SiR.sub.3).sub.2NSiH.sub.2—X+(m+1)H.sub.2N—C≡N.fwdarw.[(SiR.sub.3).sub.2NSiH.sub.2].sub.mH.sub.2-mN—C≡N+mXH.sub.3N—C≡N (salt) [0196] The reaction being preferably carried in an anhydrous and aprotic solvent or solvent mixture, such as but not limited to a C.sub.3-C.sub.24 hydrocarbon solvent, toluene, benzene, diethylether, acetonitrile, or THF. [0197] The reaction being carried at a temperature between −40° C. and 100° C., preferably at room temperature. [0198] Optionally, the formed salt being filtered from the reaction mixture and the components of the remaining liquid composition being separated by distillation. [0199] Optionally, the compound of family (4) being purified by vacuum distillation to reach an assay of >98%, more preferably or >99%, and even more preferably >99.5%, which is typical of semiconductor grade precursors [0200] Optionally, the product of family (4) may be further treated to reduce the content of dissolved XH.sub.3N—C≡N salts, for instance by exposing the product to a solid adsorbent such as activated carbon, dried Amberlyst resin or other such ion exchange resin.

[0201] To ensure process reliability, the disclosed Si-containing film forming compositions may be purified by continuous or fractional batch distillation prior to use to a purity ranging from approximately 95% w/w to approximately 100% w/w, preferably ranging from approximately 98% w/w to approximately 100% w/w. One of ordinary skill in the art will recognize that the purity may be determined by H NMR or gas or liquid chromatography with mass spectrometry. The Si-containing film forming composition may contain any of the following impurities: halides (X.sub.2), trisilylamine, monohalotrisilylamine, dihalotrisilylamine, SiH.sub.4, SiH.sub.3X, SnX.sub.2, SnX.sub.4, HX, NH.sub.3, NH.sub.3X, monochlorosilane, dichlorosilane, alcohol, alkylamines, dialkylamines, alkylimines, THF, ether, pentane, cyclohexane, heptanes, or toluene, wherein X is Cl, Br, or I. Preferably, the total quantity of these impurities is below 0.1% w/w. The purified composition may be produced by recrystallisation, sublimation, distillation, and/or passing the gas or liquid through a suitable adsorbent, such as a 4 A molecular sieve or a carbon-based adsorbent (e.g., activated carbon).

[0202] The concentration of each solvent (such as THF, ether, pentane, cyclohexane, heptanes, and/or toluene), in the purified mono-substituted TSA precursor composition may range from approximately 0% w/w to approximately 5% w/w, preferably from approximately 0% w/w to approximately 0.1 w/w. Solvents may be used in the precursor composition's synthesis. Separation of the solvents from the precursor composition may be difficult if both have similar boiling points. Cooling the mixture may produce solid precursor in liquid solvent, which may be separated by filtration. Vacuum distillation may also be used, provided the precursor composition is not heated above approximately its decomposition point.

[0203] The disclosed Si-containing film forming composition contains less than 5% v/v, preferably less than 1% v/v, more preferably less than 0.1% v/v, and even more preferably less than 0.01% v/v of any of its mono-, dual- or tris-, analogs or other reaction products. This embodiment may provide better process repeatability. This embodiment may be produced by distillation of the Si-containing film forming composition.

[0204] Purification of the disclosed Si—Containing film forming composition may also produce concentrations of trace metals and metalloids ranging from approximately 0 ppbw to approximately 500 ppbw, and more preferably from approximately 0 ppbw to approximately 100 ppbw. These metal or metalloid impurities include, but are not limited to, Aluminum(Al), Arsenic(As), Barium(Ba), Beryllium(Be), Bismuth(Bi), Cadmium(Cd), Calcium(Ca), Chromium(Cr), Cobalt(Co), Copper(Cu), Gallium(Ga), Germanium(Ge), Hafnium(Hf), Zirconium(Zr), Indium(In), Iron(Fe), Lead(Pb), Lithium(Li), Magnesium(Mg), Manganese(Mn), Tungsten(W), Nickel(Ni), Potassium(K), Sodium(Na), Strontium(Sr), Thorium(Th), Tin(Sn), Titanium(Ti), Uranium(U), Vanadium(V) and Zinc(Zn). The concentration of X (where X═Cl, Br, I) in the purified mono-substituted TSA precursor composition may range between approximately 0 ppmw and approximately 100 ppmw and more preferably between approximately 0 ppmw to approximately 10 ppmw.

[0205] Optionally, the product may be filtered to reach specifications that are typical of products used in the semiconductor industry.

[0206] Any of the compositions comprising any of the products from Families (1) through (4) may be used for the chemical vapor phase deposition (CVD) of silicon containing thin films for applications in the semiconductor, flat panel display, photovoltaic, and more generally for silicon based coatings. It is understood that the term “CVD” encompasses all embodiments in which a precursor is brought in a vapor phase in contact with a substrate on which the silicon thin film is to be deposited. As such, the term CVD may mean low pressure chemical vapor deposition (LPCVD), sub-atmospheric chemical vapor phase deposition (SA-CVD), atmospheric chemical vapor deposition (AP-CVD), Flowable chemical vapor deposition (F-CVD), Atomic Layer Deposition (ALD), Molecular Layer Deposition (MLD), Pulsed chemical vapor deposition (P-CVD), flow-modulated chemical vapor deposition (FM-CVD). Each of these techniques may be assisted by precursor or reactant activation techniques such as in-situ plasma (“Plasma Enhanced”, or PE), remote plasma (RP), hot wire (HW), and photons (UV).

[0207] The precursors of Families (1) through (4) may be used in conjunction with a co-reactant that would be typically selected from: [0208] O.sub.2, O.sub.3, H.sub.2O, H.sub.2O.sub.2, HCOOH, CO.sub.2, radicals, ions and mixtures thereof for the deposition of silicon oxide containing films [0209] N.sub.2, H.sub.2, NH.sub.3, hydrazines, primary, secondary or tertiary amines, diamines, ethanolamine, radicals, ions and mixture thereof for the deposition of silicon nitride containing films

[0210] The precursors of Families (1) through (4) may be used in conjunction with another metal or metalloid volatile precursor to deposit silicon containing films. Examples of such films include but are not limited to SiTiO, SiAlO, SiZrO, SiHfO, SiBO, SiPO, SiAsO, SiBPO, SiGeO, SiBN, SiAlN, SiTiN, CoSiN, NiSiN, TaSiN, WSiN, understanding that the composition does not take into account the potential low level carbon impurities, typically <5%, and preferably <2%, coming from the precursors and the ligands.

[0211] Multiple volatile precursors of virtually every element of the periodic table are published and available, and typically involve at least one of the following ligands or combination of ligands to achieve sufficient stability and volatility: Hydrogen, halides (Cl, Br, I, F), alkyls, alkoxy, dialkylamino, carbonyl, cyclopentadienyl and other dienes, diazadiene, amidinates, borohydrides, aminoboranes, isocyanates, acetoxy, alkylsiloxy, silyl, bis(trialkylsilyl)amide.

[0212] The compounds of families (1), (2) and (4), having a hydrolysable functional group like NR.sup.1R.sup.2, N—C≡N, or —Si—NH—Si are particularly suitable for ALD or PE-ALD of silicon oxide or silicon nitride based films, as they provide a reactive site for the precursors to react with the hydroxyl (—OH) or —NH.sub.2 groups on the surface substrate and chemically bind to it. They also have a number of silicon atom >3, and are hence expected to yield a higher growth per cycle versus the existing molecules.

[0213] The compounds of all families are also particularly suitable for LPCVD, PECVD and FCVD owing to their high silicon content and structure that is close to a silicon nitride pre-ceramic.

[0214] These compounds have a rather low vapor pressure and are suitable for deposition by condensation (C-CVD) over a substrate (by maintaining the substrate at a temperature lower than the dew point of the precursor in the deposition equipment). The thermally condensed composition may then be further treated by exposure to an oxidizing atmosphere such as O.sub.2, O.sub.3, steam, or H.sub.2O.sub.2 vapors, mixtures and plasma thereof, at a temperature preferably between 0° C. and 900° C., more preferably between 300° and 800° C., possibly in several steps to avoid the re-evaporation of the composition on the substrate, in order to convert the condensed silazane composition to a silica film. Such processes are particularly useful to deposit a dielectric film in fine trenches or holes (gap fill).

[0215] Similarly, the film may be exposed to a nitriding atmosphere (N.sub.2, NH.sub.3, hydrazines, and plasma thereof) at a temperature preferably between 100° C. and 1100° C., more preferably between 300° and 900° C. for conversion of the short chain polysilazane precursor to large chain polysilazanes and SiN pre-ceramics.

[0216] The compounds of families 1 through 4, and preferably the fully C-free compounds of family 1 and 2 may also be useful in formulation for liquid phase deposition such as spin coating, dip coating or spray coating, or as intermediates and ingredients for the synthesis of such formulations. As ingredients, these compounds may be polymerized to increase the molecular weight of the silazane, functionalized with amines or alcohols to convert some Si—H bond to more reactive alkoxy or alkylamino bonds. They may be reacted with compounds containing C═C, C═N or C═O insaturations to form Si—C bonds by hydrosilylation, preferably in the presence of a catalyst. They may be reacted with ammonia, amines or polyamines to create silazane bridges between Si atoms.

EXAMPLE

[0217] The following example illustrates an experiment performed in conjunction with the disclosure herein. The example is not intended to be all inclusive and is not intended to limit the scope of disclosure described herein.

[0218] Inside a glove box, 0.35 g (2.7 mmol) of (H.sub.3SO.sub.2—N—SiH.sub.2Cl (TSA-Cl)*was mixed with 0.39 g of Pentane. The mixture was added to 0.1 g (2.4 mmol) of Cyanamide (H.sub.2N—CN) in 0.5 g of Ether. White precipitation occurred immediately. The solution was filtered twice. Both times the initially clear filtrate turned hazy.

[0219] The presumed reaction is 2(SiH.sub.3).sub.2NSiH.sub.2—Cl+4H.sub.2N—CN.fwdarw.[(SiH.sub.3).sub.2NSiH.sub.2].sub.2-NCN+2H.sub.2N—CN*HCl

[0220] Gas Chromatographic (GC) analysis indicated the presence of monochlorosilane, ether and pentane, unreacted TSA-Cl, (SiH.sub.3).sub.2NSiH.sub.2-N—C≡N—SiH.sub.3, or [(SiH.sub.3).sub.2NSiH.sub.2].sub.2—N—C≡N (TSA.sub.2-Cyanamide). There were many other smaller, unidentified peaks. The GC spectrum of the mixture is shown in the FIGURE. One of ordinary skill in the art will recognize that a suitable distillation column would be capable of isolating the TSA.sub.2-Cyanamide from the (H.sub.3Si).sub.2—N—SiH.sub.2—NCN—SiH.sub.3. [0221] having an initial ˜85% purity as determined by GC. Applicants believe that the monochlorosilane shown in the FIGURE was an impurity in the TSA-Cl reactant.

[0222] While embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and not limiting. Many variations and modifications of the composition and method are possible and within the scope of the invention. Accordingly the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.