JP2001089572A - Phosphorus-modified silicon polymer, its production, composition containing the same and production of phosphorus-modified silicone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a phosphorus-modified silicon polymer capable of forming a phosphorus-modified silicone film in one step different from the conventional method by a film forming method not requiring a vacuum system different from the conventional film formation under the vacuum and once forming a silicone film. SOLUTION: This phosphorus-modified silicon polymer has a compositional formula: SiPxHyR1zX1w (R1 is a monovalent organic group; X1 is a halogen atom; x is 1×10-8-0.1; y is 0-3, z is 0.03-3; and w is 0-0.05). Further the method for producing the phosphorus-modified silicon polymer and the method for producing a phosphorus-modified silicone film from the phosphorus-modified silicon polymer are disclosed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coatable silicon polymer as a precursor of a silicon semiconductor material used in LSIs, thin film transistors, photoelectric conversion devices and photoreceptors, a process for producing the same, and a composition containing the same. And a method for producing phosphorus-modified silicon.

[0002]

2. Description of the Related Art Conventionally, as a method of forming an amorphous silicon film or a polysilicon film, thermal CVD (Chemical Vapor D) of monosilane gas or disilane gas is used.
(e.g., deposition), plasma CVD, optical CVD, and the like.
(J. Vac. Sci. Technology., 14
Volume 1082 (1977)), and amorphous silicon is manufactured by plasma CVD (Solid State).
Com. , Vol. 17, p. 1193 (1975)), and is used for manufacturing liquid crystal display devices having thin film transistors, solar cells, and the like.

However, in the formation of a silicon film by the CVD method, it has been awaited to further improve the following points in terms of process. Since a gas phase reaction is used, silicon particles are generated in the gas phase, so that the production yield due to contamination of the apparatus and generation of foreign matter is low. Since the raw material is gaseous, it is difficult to obtain a substrate with a uniform thickness on a substrate having an uneven surface. Low productivity due to slow film formation rate.
The plasma CVD method requires a complicated and expensive high-frequency generator or vacuum device.

[0004] In addition, in terms of material, since gaseous silicon hydride having high toxicity and reactivity is used, there is not only a difficulty in handling but also a closed vacuum device is required because it is gaseous. In general, these devices are large-scale and not only expensive, but also consume a large amount of energy in a vacuum system or a plasma system, which leads to an increase in product cost.

In recent years, a method of applying liquid silicon hydride without using a vacuum system has been proposed. JP-A-1-29661 discloses a method of forming a silicon-based thin film by liquefying and adsorbing a gaseous raw material on a cooled substrate and reacting the gaseous raw material with chemically active atomic hydrogen. However, since the silicon hydride as the raw material is continuously vaporized and cooled, not only a complicated apparatus is required, but also it is difficult to control the film thickness.

Further, Japanese Patent Application Laid-Open No. Hei 7-267621 discloses a method of applying liquid silicon hydride in a low molecular weight state to a substrate, but this method has difficulty in handling because the system is unstable. And in liquid form,
When applied to a large-area substrate, it is difficult to obtain a uniform film thickness. Furthermore, silicon hydrides easily react with oxygen and are difficult to handle.

Recently, Japanese Patent Application Laid-Open No. H11-14841 discloses a method using an organosilicon cluster modified with an organic group to make a solvent-insoluble silicon cluster soluble in a solvent. However, in this method, it was difficult to obtain a high molecular weight substance, so that a low molecular weight substance had to be used, and it was difficult to form a uniform coating film. In addition, in the production of such an organosilicon cluster, unreacted halogen remains at the end of the cluster because a silicon halide is used as a raw material. It was difficult to lead to high-purity silicon for use, and the electrical characteristics were inferior to those of ordinary silicon semiconductors. Further, there is a problem that there is no appropriate doping method for phosphorus atoms, boron atoms, and the like.

On the other hand, an example of synthesis of a solid silicon hydride polymer is reported in GB-2077710A. Here, the silicon hydride compound is synthesized by reacting the silicon hydride compound with lithium. However, since the hydrogenated polysilane obtained by this method is insoluble in a solvent, a film cannot be formed by coating.

A silicon polymer as a precursor for forming such a silicon film can be generally produced by using the monomers having the respective structural units as raw materials, for example, by the following method. (A) a method of dehalogenating polycondensation of halosilanes in the presence of an alkali metal in an amount equivalent to a halogen atom (a so-called “Kipping method”
J. Am. Chem. Soc. , 110 , 124 (19
88), Macromolecules, 23 , 342
3 (1990)); (b) Method of dehalogenating polycondensation of halosilanes by electrode reduction (J. Chem. So
c. Chem. Commun. , 1161 (199
0); Chem. Soc. Chem. Commu
n. , 897 (1992)); (c) A method for dehydrocondensation polymerization of hydrosilanes in the presence of a metal catalyst (Japanese Patent Laid-Open No.
-334551): (d) Method by anionic polymerization of disilene cross-linked with biphenyl or the like (Macro)
moleculars, 23, 4494 (1990)).
(E) After synthesizing a cyclic silicon compound substituted with a phenyl group or an alkyl group by the above method, a known method (for example, Z. anorg. Allg. Chem., 459 ,
123-130 (1979)). These halogenated cyclosilane compounds can be prepared by a known method (for example, Mh. Chem., 106, 503, 1975).
Year), (Z. Anorg. Allg. Chem.
621, p. 1517, 1995), (J.C.
hem. Soc. Chem. Commun. , 77
7, 1984), but a simple method for producing modified silicon having good semiconductor characteristics doped with boron and phosphorus atoms is still realized by any of the above methods. Not.

[0010]

An object of the present invention is to provide a novel phosphorus-modified polymer. Another object of the present invention is to provide a method for producing the phosphorus-modified polymer of the present invention. Still another object of the present invention is to form a single-stage phosphorous layer by a film forming method that does not require a vacuum system, unlike the conventional film forming method using a vacuum system, and unlike the conventional method in which a silicon film is formed once and then doped. An object of the present invention is to provide a method for producing a phosphorus-modified silicon polymer capable of forming a modified silicon film. Still another object of the present invention is to provide a composition containing the phosphorus-modified polymer of the present invention for use in the method for producing the phosphorus-modified silicon film of the present invention. Still other objects and advantages of the present invention will become apparent from the following description.

[0011]

According to the present invention, the above objects and advantages of the present invention are as follows: first, the composition formula: SiPxH
yR ¹ zX ¹ w (where R ¹ is a monovalent organic group and X ¹
Is a halogen atom and x is 1 × 10 ^{−8 to} 0.1,
y is a number from 0 to 3, z is a number from 0.01 to 3, and w is a number from 0 to 0.05).

The above objects and advantages of the present invention are, second,
Silicon tetrahalide and R^Two _nPX ^Two _3-n(Where R^Two
Is a monovalent organic group, and X^TwoIs a halogen atom, n
Is 1 or 2) and R^ThreeQX^Three _m(Where R^ThreeIs monovalent
Q is a silicon atom or a magnesium atom
Child and X^ThreeIs a halogen atom and m is 1 or
Is 3. However, when Q is a silicon atom, m is 3,
M is 1 when Q is a magnesium atom) and lithium
And / or reacting magnesium
For producing the above phosphorus-modified silicon polymer of the present invention
Achieved by law.

Thirdly, the above objects and advantages of the present invention are achieved by a composition for producing phosphorus-modified silicon, which contains the phosphorus-modified silicon polymer of the present invention. Fourth, the above objects and advantages of the present invention are as follows. Fourth, the composition for producing a phosphorus-modified silicon of the present invention is applied to a substrate, and heat treatment and / or light irradiation is performed to decompose the phosphorus-modified silicon polymer to form a phosphorus. This is achieved by a method for producing a phosphorus-modified silicon film, characterized in that the film is converted to modified silicon.

Hereinafter, the present invention will be described in detail. The phosphorus-modified silicon polymer of the present invention has a composition formula: SiPxHyR ¹
zX ¹ w (where R ¹ is a monovalent organic group, X ¹ is a halogen atom and x is 1 × 10 ^{−8 to} 0.1, y is 0 to 3, z is 0.01 to 3, w is a number from 0 to 0.05). R ¹ is a monovalent organic group, and specific examples thereof include a linear aliphatic group having 1 to 10 carbon atoms, a cyclic aliphatic group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, 7 to 20 aralkyl groups and 5 to
6-membered nitrogen-containing heterocyclic group and tri (C ₁ -C ₆ alkyl)
Silyl groups can be mentioned.

The linear aliphatic group having 1 to 10 carbon atoms may be linear or branched, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-
Alkyl groups such as butyl group, isobutyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group and texyl group; alkenyl groups such as propenyl group, 3-butenyl group, 3-pentenyl group and 3-hexenyl group And an alkynyl group such as a propargyl group, a 3-methylpropagyl group, and a 3-ethylpropagyl group. Examples of the cyclic aliphatic group having 3 to 20 carbon atoms include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a norbornyl group. Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a tolyl group, a xylyl group, an α-naphthyl group, a β-naphthyl group, an α-thiophene group, and a β-thiophene group. Further, examples of the aralkyl group having 7 to 20 carbon atoms include a benzyl group, a phenethyl group, a phenylpropyl group, and a phenylbutyl group. 1
Among these, t-butyl, texyl, phenethyl and norbornyl groups are preferred from the viewpoint of the stability of the resulting silicon polymer and the ease of decomposition when decomposed by heat and / or light. Is preferred.

Examples of the 5- or 6-membered nitrogen-containing heterocyclic group include a piperidino group, a pyrrolidino group, a morpholino group and an aziridino group. In addition, birds (C ₁
Examples of the —C ₆ alkyl) silyl group include a trimethylsilyl group and a triethylsilyl group.

In the phosphorus-modified silicon polymer of the present invention, one part of a silicon atom is bonded to a monovalent organic group.
Bonds with phosphorus and silicon atoms, and those containing hydrogen and halogen atoms also bond with these atoms. In the above formula, x is the number of phosphorus atoms, and the range of x per silicon atom is 1 × 10 ^{−8 to} 0.1.
It is preferably 1 × 10 ^{−7 to} 0.01, more preferably 1 × 10 ⁻⁶ to 1 × 10 ⁻³ . When x is less than 1 × 10 ⁻⁸ and greater than 0.1, when the phosphorus-modified polymer is converted to phosphorus-modified silicon, the resulting phosphorus-modified silicon may not sufficiently exhibit the properties as a semiconductor. is there.

Y is the number of hydrogen atoms, and the range of y per silicon atom is in the range of 0 to 3, preferably 0.05 to 2, and particularly preferably 0.07 to 2.
1.5. When y exceeds 3, the stability of the obtained silicon polymer tends to deteriorate.

Z is the number of monovalent organic groups,
The range of z per atom is 0.01-3. It is preferably 0.05 to 2, more preferably 0.1 to 1.5.
It is. When z is less than 0.01, the solubility of the obtained silicon polymer in an organic solvent is poor, and x is 3
If the ratio exceeds the above range, the coatability tends to deteriorate and the quality of the silicon film obtained by decomposition tends to deteriorate. w is the number of halogen atoms, and the range of w per silicon atom is in the range of 0 to 0.05, preferably 0 to 0.01, and particularly preferably 0. When the value of w exceeds 0.05, the storage stability of the phosphorus-modified silicon polymer tends to deteriorate.

The phosphorus-modified silicon polymer of the present invention can have an appropriate molecular weight according to the purpose, but the preferred range is from 2,000 to 150,000 in terms of polystyrene equivalent weight average molecular weight. Within this range of molecular weight, it is possible to obtain a phosphorus-modified silicon polymer having an excellent balance of coatability, film strength, and solubility in a solvent. The more preferred molecular weight of the phosphorus-modified silicon polymer of the present invention is from 5,000 to 100,000.

Furthermore phosphorus-modified silicon polymer of the present invention, the silicon of the Raman activity - has a silicon-bonded, in the Raman scattering spectrum, with a scattered light 350cm ^-1 ~550cm ^-1.

The phosphorus-modified silicon polymer of the present invention is a tetrahalogenated silicon, represented by the following formula: R ² _n PX ² _3-n wherein R ² is a monovalent organic group, X ² is a halogen atom and Is 1 or 2, a phosphorus compound represented by the following formula: R ³ QX ³ _m, wherein R ³ is a monovalent organic group, X ³ is a halogen atom, and Q is a silicon atom or a magnesium atom. And m is 1 or 3, provided that when Q is a silicon atom, m is 3 and when Q is a magnesium atom, m is 1 and any one of lithium and magnesium or It can be produced by reacting both.

Specific examples of the phosphorus compound represented by the above formula R ² _n PX ² _3-n include methyldichlorophosphine, ethyldichlorophosphine, n-propyldichlorophosphine, iso-propyldichloro. Phosphine, n-
Butyldichlorophosphine, isobutyldichlorophosphine, t-butyldichlorophosphine, n-pentyldichlorophosphine, neopentyldichlorophosphine, phenyldichlorophosphine, dimethylchlorophosphine, diethylchlorophosphine ,
-Propyl chlorophosphine, diisopropyl chlorophosphine, di-n-butyl chlorophosphine, diisobutyl chlorophosphine, di-t-butyl chlorophosphine, di-n-pentyl chlorophosphine, dineopentyl chlorophosphine, diphenyl chlorophosphine Fin, methyldibromophosphine, ethyldibromophosphine, n-propyldibromophosphine, i
so-propyldibromophosphine, n-butyldibromophosphine, isobutyldibromophosphine,
t-butyldibromophosphine, n-pentyldibromophosphine, neopentyldibromophosphine,
Phenyldibromophosphine, dimethylbromophosphine, diethylbromophosphine, di-n-propylbromophosphine, diisopropylbromophosphine, di-n-butylbromophosphine, diisobutylbromophosphine, di-t-butylbromophosphine, di-n -Pentyl bromophosphine, dineopentyl bromophosphine, diphenyl bromophosphine, piperidinodichlorophosphine, pyrrolidinodichlorophosphine, trimethylsilyldichlorophosphine, bistrimethylsilylchlorphosphine, piperidinodibromophosphine , Pyrrolidinodibromophosphine, trimethylsilyldibromophosphine, bistrimethylsilylbromophosphine, and the like.

Specific examples of the compound represented by the above formula R ³ QX ³ _m include methyltrichlorosilane, ethyltrichlorosilane, n-propyltrichlorosilane, isopropyltrichlorosilane, n-butyltrichlorosilane, and t-butyl. Trichlorosilane, cyclohexyltrichlorosilane, phenethyltrichlorosilane, 2-norbornyltrichlorosilane, phenyltrichlorosilane, methyltribromosilane, ethyltribromosilane, n-propyltribromosilane, isopropyltribromosilane, n-butyltribromo Silane, t-butyltribromosilane, cyclohexyltribromosilane, phenethyltribromosilane, 2-norbornyltribromosilane, phenyltribromosilane, methyltriiodosilane, ethyl Triiodosilane, n-propyltriiodosilane, isopropyltriiodosilane,
n-butyltriiodosilane, t-butyltriiodosilane, cyclohexyltriiodosilane, phenethyltriiodosilane, 2-norbornyltriiodosilane,
Silicon compounds such as phenyltriiodosilane; methyl magnesium chloride, ethyl magnesium chloride,
n-propylmagnesium chloride, isopropylmagnesium chloride, n-butylmagnesium chloride, t
-Butylmagnesium chloride, texylmagnesium chloride, cyclohexylmagnesium chloride, phenethylmagnesium chloride, 2-norbornylmagnesium chloride, phenylmagnesiumchloride, methylmagnesiumbromide, ethylmagnesiumbromide, n-propylmagnesiumbromide, isopropylmagnesiumbromide, n- Butyl magnesium bromide, t-butyl magnesium bromide, texyl magnesium bromide, cyclohexyl magnesium bromide, phenethyl magnesium bromide, 2-norbornyl magnesium bromide, phenyl magnesium bromide, methyl magnesium iodide, ethyl magnesium iodide, n-propyl magnesium iodide Dyed, Isopropyl Neshi um iodide, n- butylmagnesium iodide, t- butyl magnesium iodide, thexyldimethylsilyl magnesium iodide,
Organic magnesium compounds such as cyclohexyl magnesium iodide, phenethyl magnesium iodide, 2-norbornyl magnesium iodide, and phenyl magnesium iodide can be given.
The above-mentioned organometallic compounds having a t-butyl group, a texyl group, a phenethyl group, and a 2-norbornyl group are preferable from the viewpoint of the stability of the obtained silicon polymer and the elimination of an organic group by heat and / or light. These organometallic compounds are 1
Species can be used alone or in combination of two or more.

In the production method of the present invention, the tetrahalogenated silane, the compound of the above formula R ² _n PX ² _{3-n and} the compound of the above formula R ³ QX ³ _m are combined with lithium and / or
Alternatively, by reacting with a magnesium metal, a phosphorus-modified silicon polymer having an R ² group, an R ³ group and / or a halogen atom at the terminal of the molecule can be obtained. Tetrahalogenated _{^{silane, R 2 n PX 2 3-}} n, and the proportion of R ³ QX ³ _m are tetra halogenated silane _{^{/ R 2 n PX 2 3-}} n /
R ³ QX ³ _m = 1/1 × 10 ^{-8 to} 0.1 / 0.01 to 10
(Molar ratio). Preferably 1/1 × 10 ^{-7 to} 0.0
1 / 0.1 to 5 and more preferably 1/1 × 10
⁻⁶ to 1 × 10 ⁻³ /0.5 to ³ .

When the amount of R ² _n PX ² _3-n used is less than 1 × 10 ⁻⁸ mol per mol of tetrahalogenated silane, the amount of phosphorus incorporated during the synthesis varies greatly, so When the amount is more than mol, the obtained silicon polymer is easily oxidized and has poor stability. When the use amount of R ³ QX ³ _m is less than 0.01 mol per 1 mol of the tetrahalogenated silane, the molecular weight of the obtained phosphorus-modified silicon polymer becomes small, and the film-forming property deteriorates. If it exceeds 10, the yield of the solvent-soluble phosphorus-modified silicon polymer decreases.

The lithium and / or magnesium to be reacted therewith are a tetrahalogenated silane, R
² _n PX ² _3-n and R ³ QX ³ _{m are used} to reductively remove a halogen atom to form a lithium halide and / or a magnesium halide. the total amount of at least equivalent amount of the halogen atoms of _{^{R 2 n PX 2 3-n}} , and R ³ QX ³ _m.

In the reaction of the above step, the reaction can be promoted by irradiating ultrasonic waves from the outside as necessary. The frequency of the ultrasonic wave used here is 1
Those having a frequency of about 0 to 70 KHz are desirable.

In the production of the silicon polymer of the present invention,
As the solvent used in the above step, an ether solvent can be preferably used. The hydrocarbon solvent used in the ordinary Kipping reaction has a drawback that the yield of the soluble phosphorus-modified silicon polymer to be produced is low. Examples of ether solvents include diethyl ether, di-
n-propyl ether, di-isopropyl ether, dibutyl ether, ethyl propyl ether, anisole, phenetole, diphenyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, Dipropylene glycol dibutyl ether, dipropylene glycol methyl ethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol methyl ethyl ether, propylene glycol dimethyl ether, propylene glycol die Ether, propylene glycol dibutyl ether, propylene glycol methyl ethyl ether, tetrahydrofuran, dioxane, and the like. Of these, the above formula R ³ QX ³ _m
In terms of solubility of the compound represented by, diethyl ether,
Preferred are tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether.

It is desirable to remove water from these ether solvents before using them in the reaction. As a method for removing water, a degassing distillation method in the presence of sodium-benzophenone ketyl and the like are preferable. The use amount of these solvents is not particularly limited, but is usually 1 to 20 parts by weight with respect to the above-mentioned silicon tetrahalide, preferably 3 to 20 parts by weight.
To 10 parts by weight.

The reaction temperature in the above step is preferably -78.
° C to + 100 ° C. If the reaction temperature is -78 ° C or lower, the reaction rate tends to be low and the productivity tends to be poor. If the reaction temperature is higher than + 100 ° C, the reaction becomes complicated and the resulting phosphorus-modified silicon polymer has poor solubility. Easy to be.

The phosphorus-modified silicon polymer produced as described above can sufficiently exhibit the intended performance targeted by the present invention.
4 and / or with MgH ₂ . The phosphorus-modified silicon polymer before these treatments contains a trace amount of unreacted hydrolyzable halogen atoms at the terminal of the molecule. By performing the above treatment, the residual halogen atoms are reduced, and the stable hydrogen atoms are removed. , The stability of the phosphorus-modified silicon polymer can be improved. The amount of LiAlH ₄ and / or MgH ₂ used must be at least equivalent to the remaining halogen atoms. The solvent used in this processing step is LiAlH ₄
The solvent is not particularly limited as long as it does not react with MgH _2, and is usually an ether solvent, and the same solvent as the ether solvent exemplified in the previous reaction step can be used here. These can be used alone or in combination of two or more.

The reaction temperature in this treatment step is -78 ° C. to +3
0 ° C. is preferred. When the temperature is lower than -78 ° C, the reaction is slow, and the productivity tends to deteriorate. On the other hand, when the temperature is higher than 30 ° C, the solubility of the reaction product is lowered and the production yield of the silicon polymer of the present invention is lowered. In general, the reaction in both the reaction step and the treatment step is preferably performed in an inert gas such as argon or nitrogen.

The phosphorus-modified silicon polymer of the present invention is soluble in toluene and other organic solvents, and when forming a film, it is usually dissolved in a solvent to form a composition for producing phosphorus-modified silicon, and then applied by a coating method. A film of the phosphorus-modified silicon polymer can be formed. Phosphorus-modified silicon polymer of the present invention, in addition to toluene, hydrocarbon solvents, ketone solvents,
A composition for producing phosphorus-modified silicon can be prepared using an ether solvent or an ester solvent. Specific examples of the hydrocarbon solvent include n-pentane, n-hexane, cyclohexane, n-heptane, n-octane, decane, dicyclopentadiene, benzene, toluene, xylene, durene, indene, tetrahydronaphthalene, decahydronaphthalene And squalane. Further, as the ketone solvent, for example, acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, dibutyl ketone, methyl isobutyl ketone,
Examples include methyl amyl ketone, cyclopentanone, cyclohexanone, and cycloheptanone. Examples of the ether-based solvent include diethyl ether, di-n-propyl ether, di-isopropyl ether,
Dibutyl ether, ethyl propyl ether, anisole, phenetole, diphenyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, dipropylene glycol methyl Ethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol methyl ethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether , Mention may be made of propylene glycol methyl ethyl ether, tetrahydrofuran, dioxane and the like. Further, as an ester solvent,
Examples thereof include ethyl acetate, propyl acetate, butyl acetate, isoamyl acetate, methyl sesosolve acetate, ethyl sesosolve, butyl cellosolve, ethyl lactate, propyl lactate, butyl lactate, isoamyl lactate, and propylene glycol methyl ether acetate. The silicon polymer of the present invention can be made into a solution using these organic solvents. These organic solvents can be used alone or in combination of two or more. The concentration of the composition for producing phosphorus-modified silicon of the present invention can be appropriately adjusted depending on the purpose, and the concentration of the solution is usually 0.05% to 30% by weight. The composition for producing phosphorus-modified silicon prepared by dissolving the solvent-soluble silicon polymer of the present invention in the above-mentioned solvent has excellent coatability, and can easily form a coating film of the phosphorus-modified silicon polymer on an appropriate substrate. it can.

As a method for applying the composition for producing the phosphorus-modified silicon of the present invention, methods such as spin coating, roll coating, curtain coating, dip coating, spraying, and ink jetting can be used.
The application is preferably performed in an atmosphere of an inert gas such as nitrogen, helium, or argon. Further, if necessary, the reaction can be performed in an atmosphere containing a reducing gas such as hydrogen. When the spin coating method is used, the rotation speed of the spinner is determined by the thickness of the thin film to be formed and the composition of the coating solution, but is preferably 100 to 5,000 rpm, more preferably 300 to 3,000 rpm.
After the application, a heat treatment is performed to remove the solvent. The heating temperature varies depending on the type and boiling point of the solvent used, and is, for example, 100 ° C to 200 ° C. The atmosphere is preferably performed in the same inert gas as nitrogen, helium, argon or the like used in the above-mentioned coating step.

The phosphorus-modified silicon polymer coating film of the present invention can be converted to a phosphorus-modified silicon film by heat treatment and / or light irradiation treatment. The phosphorus-modified silicon film thus obtained is amorphous or polycrystalline. However, in the case of heat treatment, the ultimate temperature is generally about 550 ° C. or less, amorphous, and above that temperature, the polycrystalline phosphorus-modified silicon film is polycrystalline. Is obtained. When it is desired to obtain an amorphous phosphorus-modified silicon film, the temperature is preferably from 300 ° C. to 55 ° C.
0 ° C, more preferably 350 ° C to 500 ° C, is used. When the reached temperature is lower than 300 ° C., the thermal decomposition of the organic groups of the phosphorus-modified silicon polymer does not sufficiently proceed, and a phosphorus-modified silicon film having a sufficient thickness may not be formed. As an atmosphere for the heat treatment, an atmosphere containing an inert gas such as nitrogen, helium, or argon or a reducing gas such as hydrogen can be used.

As described above, when the phosphorus-modified silicon polymer of the present invention is converted into a phosphorus-modified silicon film by heat treatment and / or light irradiation treatment, silicon atoms are liable to react with oxygen to form silicon-oxygen bonds. The phosphorus-modified silicon polymer before conversion preferably does not contain oxygen atoms as impurities, and contains at most 0.01 oxygen atoms per silicon atom. When the phosphorus-modified silicon polymer contains more than 0.01 atoms of oxygen atoms, it is difficult to obtain a high-quality one when converted to a phosphorus-modified silicon film.

The light source used in the light treatment of the present invention includes a low-pressure or high-pressure mercury lamp, a deuterium lamp, or a discharge light of a rare gas such as argon, krypton, or xenon, a YAG laser, an argon laser, or a carbon dioxide. Gas laser, XeF, XeCl, XeBr, KrF, Kr
An excimer laser such as Cl, ArF, or ArCl can be used as a light source. These light sources generally have an output of 10 to 5000 W,
Usually, 100 to 1000 W is sufficient. The wavelength of these light sources is not particularly limited as long as it is absorbed by the phosphorus-modified silicon polymer to some extent.
m. The use of laser light is particularly preferable in terms of conversion efficiency to a phosphorus-modified silicon film. The temperature at the time of these light treatments is usually from room temperature to 500 ° C., and can be appropriately selected according to the semiconductor characteristics of the obtained phosphorus-modified silicon film.
In particular, when it is desired to obtain a polycrystalline phosphorus-modified silicon film, the above-mentioned amorphous phosphorus-modified silicon film can be converted into a polycrystalline phosphorus-modified silicon film by irradiating the above-mentioned light.

The composition for producing phosphorus-modified silicon according to the present invention may contain a trace amount of a surface tension controlling material such as a fluorine-based, silicone-based, or nonionic-based material as needed as long as the purpose and function are not impaired. it can. The viscosity of the composition thus prepared for producing the phosphorus-modified silicon is usually 1 to 50.
It is in the range of 0 mPa · s, and can be appropriately selected according to the coating apparatus and the target coating film thickness.

The substrate on which the phosphorus-modified silicon polymer solution obtained in the present invention is applied is not particularly limited, but may be any of ordinary quartz, borosilicate glass, soda glass, gold, silver,
A metal substrate of copper, nickel, titanium, aluminum, tungsten, or the like, and a glass or plastic substrate having these metals on the surface can be used.

[0041]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Synthesis of Phosphorus-Modified Silicon Polymer A 3-L four-necked flask equipped with a thermometer, a cooling condenser, a dropping funnel, and a stirrer was replaced with argon gas, and dried with 1 L of tetrahydrofuran.
And 60 g of magnesium metal were charged and bubbled with argon gas. While stirring this at 20 ° C., 170 g of tetrachlorosilane, t-butyldichlorophosphine 1
A mixture of 6 g and 137 g of t-butyl bromide was slowly added from a dropping funnel. With the addition of the first 20 g, the reaction system started to reflux and the system was colored brown. Further, the remainder was slowly dropped so that reflux was maintained without external heating. After completion of the dropwise addition, stirring was further continued at room temperature for 3 hours to obtain a black-brown reaction mixture.

[0043]Recovery of phosphorus-modified silicon polymer The dark brown reaction mixture obtained above was poured into 15 L of ice water.
And the resulting polymer was precipitated. The polymer produced is good with water
Washing and vacuum drying give brown solid polymer
75 g were obtained.Analysis of phosphorus modified silicon polymer Weight average of this polymer in terms of polystyrene by GPC
The molecular weight was 12,000. In addition, IR spectrum
and¹Existence of t-butyl group from H-NMR spectrum
Was suggested. The Raman scattering spectrum of the polymer
502cm^-1Strong Raman scattered light is observed, and Si-S
The presence of an i-bond was found. Elemental analysis of the polymer
After that, SiP_0.1H_4.2C_1.2Cl_0.1Met. this
Phosphorus-modified silicon polymer has the composition formula from the above analysis results.
Is SiP_0.1H_1.5 ^tBu_0.3Cl _0.1Met.

Example 2 Synthesis of Phosphorus-Modified Silicon Polymer The synthesis operation of a phosphorus-modified silicon polymer was carried out in the same manner as in Example 1 to obtain a black-brown reaction mixture. LiAlH ₄ treatment of phosphorus-modified silicon polymer The black-brown reaction mixture obtained above was added to a solution of 5 g of LiAlH ₄ suspended in 300 ml of dry tetrahydrofuran, and reacted at room temperature for 5 hours. The reaction mixture was poured into 15 L of ice water to precipitate the formed polymer. The resulting polymer was thoroughly washed with water and vacuum dried to obtain 68 g of a brown solid polymer. Analysis of phosphorus-modified silicon polymer The weight average molecular weight of this polymer in terms of polystyrene by GPC was 12,000. The GPC spectrum is shown in FIG. The IR spectrum and the ¹ H-NMR spectrum indicated the presence of a t-butyl group. The Raman scattering spectrum of this phosphorus-modified silicon polymer shows 5
Intense Raman scattered light at 02 cm ^-1 was observed.
The presence of the bond was confirmed. Elemental analysis of this phosphorus-modified silicon polymer revealed SiP _0.1 H _4.3 C _1.2 . This silicon polymer was found to have a composition formula of SiP _0.1 H _1.6 ^t Bu _0.3 from the above analysis results.

Example 3 Synthesis of Phosphorus-Modified Silicon Polymer The synthesis operation of the phosphorus-modified silicon polymer was carried out in the same manner as in Example 1 to obtain a black-brown reaction mixture. MgH ₂ treatment of phosphorus-modified silicon polymer The black-brown reaction mixture obtained above was treated with 10 g of MgH ₂
Was added to a solution suspended in 300 ml of dried tetrahydrofuran, and reacted at room temperature for 5 hours. The reaction mixture was poured into 15 L of ice water to precipitate the formed polymer.
The resulting polymer was thoroughly washed with water and vacuum dried to obtain 77 g of a brown solid polymer. Analysis of phosphorus-modified silicon polymer The weight average molecular weight of this polymer in terms of polystyrene by GPC was 12,000. The IR spectrum and ¹ H-NMR spectrum of this polymer were substantially the same as those of the polymer obtained in Example 2. In the Raman scattering spectrum of this phosphorus-modified silicon polymer, strong Raman scattering light at 490 cm ^-1 was observed, and the existence of Si-P bonds was confirmed. Elemental analysis of this phosphorus-modified silicon polymer showed that SiP _0.1 H _4.3
C was _1.2 . This silicon polymer was found to have a composition formula of SiP _0.1 H _1.6 ^t Bu _0.3 from the above analysis results.

Example 4 Preparation of Composition for Production of Phosphorus-Modified Silicon 10 g of the phosphorus-modified silicon polymer obtained in Example 1 was dissolved in 90 ml of cyclohexanone to prepare a composition for production of phosphorus-modified silicon. Production of phosphorus-modified silicon After spin-coating the above composition on a quartz substrate,
After drying at 0 ° C. for 10 minutes, a phosphorus-modified silicon polymer film having a thickness of 1.2 μm was formed. When the coated substrate was heated to 700 ° C. in an argon atmosphere containing 3% of hydrogen, the t-butyl group was removed by heat, and a silicon film containing phosphorus remained on the substrate. The phosphorus-modified silicon film was found to be 100% amorphous from the Raman scattering spectrum. X is added to this amorphous silicon.
When irradiated with an eCl excimer laser (308 nm), silicon was polycrystallized and the crystallization ratio was 75%.
When the constituent elements of the polycrystallized silicon film were measured by XMA spectrum, it was confirmed that only silicon and phosphorus were included. FIG. 2 shows the XMA spectrum at this time. In the thermal decomposition of the phosphorus-modified silicon polymer, when the thermal decomposition behavior was measured by pyrolysis GC / MS, isobutylene was detected as a decomposition product.

Example 5 Preparation of Composition for Production of Phosphorus-Modified Silicon 10 g of the phosphorus-modified silicon polymer obtained in Example 2 was dissolved in a mixed solvent of 80 ml of toluene and 10 ml of tetrahydrofuran. The composition was prepared. Production of Phosphorus-Modified Silicon Except for using the composition obtained above, production of phosphorus-modified silicon was carried out in the same manner as in Example 3 to obtain a silicon film containing phosphorus. The phosphorus-modified silicon film was found to be 100% amorphous from the Raman scattering spectrum.
When this amorphous silicon was irradiated with a XeCl excimer laser (308 nm), the silicon was polycrystallized and the crystallization ratio became 75%. When the constituent elements of the polycrystallized silicon film were measured by XMA spectrum, it was confirmed that only silicon and phosphorus were included. In the thermal decomposition of the phosphorus-modified silicon polymer, when the thermal decomposition behavior was measured by pyrolysis GC / MS, isobutylene was detected as a decomposition product.

Example 6 A phosphorus-modified silicon polymer was synthesized in the same manner as in Example 2 except that 348 g of tetrabromosilane was used instead of 170 g of tetrachlorosilane.
Perform ₄ treatment operations to obtain 65 g of phosphorus-modified silicon polymer.
I got The weight average molecular weight of this silicon polymer in terms of polystyrene measured by GPC was 33,000. The degree of dispersion showing the molecular weight distribution was 4.0. The IR spectrum and NMR spectrum of this silicon polymer were almost the same as those of the silicon polymer obtained in Example 1. Elemental analysis of this silicon polymer revealed that SiP _0.1 H _4.0 C
_{It was 1.2} and no oxygen atoms were detected. Based on the above analysis results, this silicon polymer has a composition formula of SiP _0.1 H
_1.3 ^t Bu _0.3 .

Example 7 Phosphorus-modified silicon polymer was prepared in the same manner as in Example 2 except that 192 g of tertiary butyltrichlorosilane and 85 g of magnesium metal were used instead of the tertiary butylmagnesium chloride used in Example 2 above. Synthesis of LiAlH
Perform ₄ treatment operations, 89 g of phosphorus-modified silicon polymer
I got The weight average molecular weight in terms of polystyrene of this phosphorus-modified silicon polymer determined by GPC was 13,000. The degree of dispersion indicating the molecular weight distribution was 4.5. The IR spectrum and ¹ H-NMR spectrum of this silicon polymer were substantially the same as the silicon polymer obtained in Example 1. Elemental analysis of this silicon polymer,
SiP _0.1 H _3.0 C _1.2 , and no oxygen atom was detected. This silicon polymer was found to have a composition formula of SiP _0.1 H _0.3 ^t Bu _0.3 from the above analysis results.

Example 8 The same procedure as in Example 6 was carried out except that 49 g of lithium was used instead of magnesium and the reaction temperature was set at 0 ° C., to synthesize a phosphorus-modified silicon polymer.
_Four treatment operations were performed to obtain 82 g of a silicon polymer.
The polystyrene-equivalent weight average molecular weight of this phosphorus-modified silicon polymer determined by GPC was 85,000. The degree of dispersion indicating the molecular weight distribution was 4.5. The IR spectrum and NMR spectrum of this silicon polymer were substantially the same as those of the silicon polymer obtained in Example 2. Elemental analysis of this phosphorus-modified silicon polymer revealed that SiP
_0.1 H _3.1 C _1.2 , and no oxygen atom was detected. This silicon polymer has a composition formula of S
iP _0.1 H _0.4 ^t Bu _0.3 .

Example 9 5 g of the phosphorus-modified silicon polymer obtained in Example 2 was dissolved in 95 g of toluene to prepare a composition for producing a transparent brown phosphorus-modified silicon. The viscosity of this solution is 15 mP
a · s. When this solution was observed for a solution stored at 40 ° C. for one week, no change in appearance was observed, and the viscosity was measured again. However, no change in viscosity was observed at 15 mPa · s.

Example 10 The composition for producing phosphorus-modified silicon obtained in Example 9 was spin-coated on a quartz substrate, and then heated and dried in a clean oven at 100 ° C. for 30 minutes.
This phosphorus-modified silicon polymer film is treated under an argon atmosphere with X
500 mJ / eCl excimer laser (308 nm)
cm ^{2 was} irradiated. When the 2P orbital energy of the silicon atom of the irradiated part of the film is measured by ESCA spectrum, 9
A peak was observed at 9.0 eV. In addition, according to the XMA spectrum, it was confirmed that the constituent elements of the resulting film were only silicon and phosphorus. From this, it was found that by directly irradiating the phosphorus-modified silicon polymer with the XeCl excimer laser, the phosphorus-modified silicon polymer film was converted into a phosphorus-containing silicon film.

Comparative Example 1 Synthesis of a phosphorus-modified silicon polymer was attempted in the same manner as in Example 1 except that trichlorophosphine was used instead of t-butyldichlorophosphine.
A red precipitate was deposited in the middle of the reaction, and the reaction system became heterogeneous. The precipitate was separated by filtration from the reaction mixture, and the polymer was recovered from the soluble part in the same manner as in Example 1 to obtain 55 g of a brown polymer. The weight average molecular weight of this polymer in terms of polystyrene by GPC was 15,000.
The presence of a t-butyl group was confirmed from the IR spectrum and the ¹ H-NMR spectrum. However, elemental analysis of this polymer showed that SiH _4.2 C _1.2 Cl
_0.1 , and no phosphorus atom was detected. From the above analysis result, the composition formula of this polymer is as follows: SiH _1.5 ^t Bu _0.3
Cl was _0.1 and it was found that no phosphorus atom was contained. The precipitate deposited during the reaction was found to be red phosphorus.

[0054]

According to the phosphorus-modified silicon polymer of the present invention, unlike the conventional film forming method in a vacuum system, a silicon film is formed once and then doped with phosphorus by a film forming method not requiring a vacuum system. Unlike the conventional method, a phosphorus-modified silicon film can be formed in one step.

[Brief description of the drawings]

FIG. 1 is a GPC spectrum of the phosphorus-modified silicon polymer obtained in Example 2.

FIG. 2 is an XM of the phosphorus-modified silicon obtained in Example 4.
It is an A spectrum figure.

Claims (5)

[Claims] 1. A composition formula: SiPxHyR ¹ zX ¹ w (where R ¹ is a monovalent organic group, X ¹ is a halogen atom, and x is 1 × 10 ^{−8 to} 0.1, y is 0 to 3 and z are 0.
01 to 3 and w is a number from 0 to 0.05). 2. The method according to claim 2, wherein the silicon tetrahalide and R ² _n PX ² _3-n
(Where R ² is a monovalent organic group, X ² is a halogen atom, and n is 1 or 2) and R ³ QX ³ _m (where R ³ is a monovalent organic group) Wherein Q is a silicon atom or a magnesium atom, X ³ is a halogen atom and m is 1 or 3, provided that when Q is a silicon atom, m is 3 and when Q is a magnesium atom, m is 1 Is reacted with lithium and / or magnesium. The method for producing a phosphorus-modified silicon polymer according to claim 1, wherein 3. The method for producing a modified silicon polymer according to claim 1, wherein the reaction product obtained in claim 2 is further treated with LiAlH ₄ and / or MgH _2. 4. A composition for producing a phosphorus-modified silicon, comprising the phosphorus-modified silicon polymer according to claim 1. 5. A method for applying the composition for producing phosphorus-modified silicon according to claim 4 to a substrate and subjecting the composition to heat treatment and / or light irradiation to decompose the phosphorus-modified silicon polymer to convert it to phosphorus-modified silicon. A method for producing a phosphorus-modified silicon film.