JP4872419B2 - Method for producing polysilane-modified silicon fine particles and method for forming silicon film - Google Patents

Description

  The present invention relates to a method for producing polysilane-modified silicon fine particles and a method for forming a silicon film, and in particular, a method for producing polysilane-modified silicon fine particles to be a film forming material for forming a silicon film by a coating method or a dipping method, and a silicon film It relates to a forming method.

  Conventionally, as a method for forming an amorphous silicon (hereinafter referred to as “a-Si”) film or a polysilicon (hereinafter referred to as “poly-Si”) film, thermochemical vapor deposition using silicon hydride gas (Chemical Vapor Deposition) is used. (CVD)) method, plasma CVD method, photo CVD method, vapor deposition method, sputtering method and the like are used. In general, the plasma CVD method is used for the a-Si film (see Non-Patent Document 1), and the thermal CVD method is widely used for the poly-Si film (see Non-Patent Document 2).

In the plasma CVD method, which is most frequently used to form an a-Si film, silane (SiH ₄ ) and disilane (Si ₂ H ₆ ) are decomposed by glow discharge, and an a-Si thin film is grown on the substrate. I am letting. For the substrate, crystalline silicon, glass, heat-resistant plastic or the like is used, and it can be grown usually at 400 ° C. or lower. A big advantage is that large-area products can be produced at relatively low cost. As for the poly-Si film, the a-Si film made by the above-mentioned method is irradiated with a pulsed excimer laser at intervals of about 25 ns, the a-Si film is heated and dissolved, cooled, and then again. Crystallization is caused to form a poly-Si film.

  Further, as a CVD method using higher-order silicon hydride, a method in which high-order silicon hydride gas is thermally decomposed under a pressure higher than atmospheric pressure (see Patent Document 1), and cyclic silicon hydride gas is thermally decomposed. A method (see Patent Document 2), a method using branched silicon hydride (see Patent Document 3), a method of performing thermal CVD of trisilane or higher silicon hydride gas at 480 ° C. or lower (see Patent Document 4), etc. Proposed.

  However, when a silicon film is formed by a CVD method, since a gas phase reaction is used, particles are generated in the gas phase, which causes problems such as contamination of a film forming apparatus and a decrease in device yield. In addition, since the raw material is used in a gaseous state, it is difficult to obtain a film having good step coverage on a substrate having an uneven surface, and there is a problem that the throughput is low because the film formation speed is low. In particular, in the plasma CVD method, not only a complicated and expensive apparatus such as a high-frequency generator is required, but also an expensive high vacuum apparatus is necessary.

  On the other hand, apart from the CVD method as described above, formation of a silicon film by a coating method that does not require an expensive apparatus has been studied. As an example of a method for forming such a silicon film, a silicon film that is heated after being coated with liquid silicon hydride and then subjected to a decomposition reaction in the coating film through a thermal history including a temperature rising process. Has been reported (see Patent Document 5). Also reported is a method of applying a composition comprising a mixture of silicon fine particles obtained by pulverizing single crystal silicon and liquid silicon hydride on a substrate, and heating the resulting coating to form a polysilicon film. (See Patent Document 6).

Spear, W.E, `` Solid State Com. '', 1975, Vol. 17, p. 1193 Kern, W, `` Journal of Vacuum Science and Technology '', 1977, Vol. 14 (5), p.1082 Japanese Patent Publication No. 5-469 Japanese Examined Patent Publication No. 4-62703 JP 60-26665 A Japanese Patent Publication No. 5-56852 Japanese Patent No. 3517934 JP-A-2005-332913

  However, the method for forming a silicon film described in Patent Document 5 has a difficulty in requiring a complicated apparatus for handling liquid silicon hydride, and it is difficult to control the thickness of the silicon film. In addition, in the method for forming a silicon film described in Patent Document 6, the work of removing the oxide film on the surface of the fine particles is complicated by using fine particles obtained by pulverizing single crystal silicon, and a uniform continuous film having no defects is obtained. Difficult to do. Further, since the silicon film is formed by mixing liquid silicon hydride and silicon fine particles, there is a problem that defects are likely to occur at the interface between the silicon fine particles and the silicon hydride during film formation.

  The present invention provides a method for producing polysilane-modified silicon fine particles as a film forming material for forming a silicon film without requiring large-scale equipment, and a method for forming a silicon film using the polysilane-modified silicon fine particles. For the purpose.

  In order to achieve the above-described object, the method for producing polysilane-modified silicon fine particles according to the present invention includes adding a silicon fine particle to a liquid containing a polysilane having a silyl anion at the terminal, thereby forming a polysilane on the surface of the silicon fine particle. It is characterized by producing polysilane-modified silicon fine particles bonded with.

  According to such a method for producing polysilane-modified silicon fine particles, by adding silicon fine particles to a liquid containing polysilane having a terminal silyl anion to produce polysilane-modified silicon fine particles, for example, a silicon film is formed by a coating method. A film forming material for forming can be generated.

  The method for forming a silicon film of the present invention is a method in which a silicon film is formed on the surface of a substrate, wherein the liquid containing polysilane-modified silicon fine particles bonded with polysilane on the surface of the silicon fine particles is in contact with the surface of the substrate. Thus, a silicon film is formed on the surface of the substrate by light irradiation or heat treatment.

  According to such a silicon film forming method, the polysilane of the polysilane-modified silicon fine particles is converted into amorphous silicon or by performing light irradiation or heat treatment in a state where the liquid containing the polysilane-modified silicon fine particles is in contact with the surface of the substrate. It becomes polycrystalline silicon. In general, the silicon fine particles are composed of single crystal silicon or polycrystalline silicon. Thereby, a silicon film can be formed on the surface of the substrate by a coating method. Further, by forming the silicon film using the polysilane-modified silicon fine particles, the minimum film thickness of the silicon film is regulated to some extent by the diameter of the polysilane-modified silicon fine particles, so that the film thickness can be easily controlled.

  As described above, according to the method for producing polysilane-modified silicon fine particles and the method for forming a silicon film using the polysilane-modified silicon fine particles of the present invention, the silicon film can be formed by a coating method. In addition to simplifying the formation process, the substrate having a rough surface can be sufficiently coated with the surface. Furthermore, since it is easy to control the thickness of the silicon film to be formed, a silicon film with a controlled thickness can be formed with high reproducibility.

  Hereinafter, an example of an embodiment of the method for producing polysilane-modified silicon fine particles and the method for forming a silicon film using the polysilane-modified silicon fine particles of the present invention will be described in detail.

(Method for producing polysilane-modified silicon fine particles)
A method for producing the polysilane-modified silicon fine particles of the present embodiment will be described with reference to the schematic process chart of FIG. As shown in FIG. 1 (a), a reducing agent is added to a solvent containing a silicon compound and reacted to produce polysilane 11 having a terminal converted to a silyl anion. Here, for example, a reducing agent made of lithium (Li) is added in a solvent made of tetrahydrofuran (THF) having a water concentration of 10 ppm or less under an inert gas atmosphere such as argon (Ar), in which dissolved oxygen is previously substituted with Ar. Added. Next, with Ar bubbling and stirring at 0 ° C., a silicon compound composed of liquid diphenyldichlorosilane is dropped into the solvent to which the reducing agent has been added, and stirring is performed until Li completely disappears after the dropping is completed. . Thereafter, unreacted Li is removed to produce a Li adduct of polysilane 11 composed of polydiphenylsilane. The terminal of this polysilane 11 is silyl anionized. The Si number of the polysilane 11 obtained by the above synthesis method is mainly 5 linear molecules, and the Si number is generated in the range of 4-7.

  Here, an example in which one end of the polysilane 11 is converted into a silyl anion is illustrated, but both ends of the polysilane 11 may be converted into a silyl anion, or these may be mixed.

  In addition, here, an example in which polysilane 11 is synthesized from a silicon compound composed of diphenyldichlorosilane and a terminal is converted to a silyl anion has been described. However, the present invention is not limited thereto, and for example, a reducing agent composed of Li is added. Alternatively, a Li adduct of polysilane 11 may be formed by adding a solution obtained by dissolving polysilane 11 in THF, for example, to a solvent composed of THF, and the terminal of polysilane 11 may be converted into a silyl anion. As in this case, when polysilane is used from the beginning, the polysilane may be cyclic or chain-like.

Furthermore, here, as the polysilane 11 having a terminal silyl anion, a linear polydiphenylsilane having a phenyl group in the side chain will be described as an example. However, the present invention is not limited to this, and the general formula (1 As long as it is polysilane 11 whose main skeleton is composed of Si, as shown in FIG.

  Here, R and R ′ shown in the general formula (1) include atoms such as hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, boron, and halogen, a hydroxyl group, a substituted or unsubstituted carbonyl group, and a substituted group. Or an unsubstituted ester group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a cyano group , A nitro group, an amino group, an amide group, a substituent such as a thiol group. N is a positive integer of 2 or more, and R and R ′ may be the same or different.

  Next, silicon fine particles 12 are prepared. Here, as the silicon fine particles 12, an existing product, a crushed crystalline silicon, or a synthetic method may be used. However, since the silicon fine particles 12 produced by the synthesis method can be bonded to the above-described polysilane 11 in a state of being dispersed in a solvent as compared with the case where silicon fine particles obtained by pulverizing crystalline silicon are used. It is not necessary to remove the oxygen film adhering to the surface of the silicon fine particles 12, which is preferable. Further, as will be described later, since the surface of the silicon fine particles is modified with chlorine (Cl) or the like in the process of synthesizing the silicon fine particles 12, the polysilane 11 having the above-mentioned terminal silyl anion is converted into the silicon fine particles 12 in a later step. When bonding to the surface, it can be easily bonded by a substitution reaction of Cl and silyl groups, which is preferable.

Here, the silicon fine particles 12 are manufactured by a synthesis method. In this case, for example, naphthalene and sodium are added to a solvent composed of 1,2-dimethoxyethane having a water concentration of 10 ppm or less in which the dissolved oxygen is substituted with Ar by bubbling under an inert gas atmosphere such as Ar. Stir. By adding naphthalene and sodium into the solvent, a complex of naphthalene and sodium is generated and acts as a reducing agent. On the other hand, a silicon compound made of silicon tetrachloride (SiCl ₄ ) is dissolved in a solvent made of 1,2-dimethoxyethane having a water concentration of 10 ppm or less in which dissolved oxygen is substituted with Ar.

Next, 1,2-dimethoxyethane in which silicon tetrachloride (SiCl ₄ ) is dissolved is dropped into 1,2-dimethoxyethane to which naphthalene and sodium are added, and is reacted for, for example, 12 hours. Thereafter, unreacted naphthalene, sodium, and generated sodium chloride are removed, and single crystal silicon fine particles 12 having Cl bonded to the surface are generated. According to this method, the silicon fine particles 12 are formed with a diameter of 1 nm to 20 nm, but the silicon fine particles 12 having a diameter of about 1 nm to 10 μm can be used. The atoms bonded to the surface of the silicon fine particles 12 are not limited to Cl, and may be other halogen atoms such as bromine (Br). Further, the polycrystalline silicon fine particles 12 may be manufactured by a synthesis method different from the above.

  Next, a liquid in which the silicon fine particles 12 are dispersed in a solvent made of 1,2-dimethoxyethane and the above-described THF solution of the polydiphenylsilane Li adduct are mixed and sufficiently reacted. Drip into the filled container. As a result, as shown in FIG. 1 (b), one end of the polysilane 11 has a silicon fine particle 12 due to a substitution reaction between Cl on the surface of the silicon fine particle 12 and a polysilane 11 made of polydiphenylsilane having a terminal silyl anionized. Polysilane-modified silicon fine particles 13 that are covalently bonded to the surface of the film are formed as precipitates. Thereafter, the precipitate is washed with a solvent composed of, for example, cyclohexane.

  Although an example in which one end of the linear polysilane 11 is bonded to the silicon fine particle 12 is illustrated here, the present invention is not limited to this, and as described above, both ends of the polysilane 11 are converted into silyl anions. In some cases, both ends of the polysilane 11 may be bonded to the surface of the silicon fine particles 12.

  Here, the polysilane-modified silicon fine particles 13 obtained by the above-described steps and having the polysilane 11 made of polydiphenylsilane bonded to the surface of the silicon fine particles 12 may be used as a film forming material for the silicon film described later. Further, silicon fine particles 12 to which a polysilane 11 having a substituent or atom other than a phenyl group as a side chain is bonded can also be used as a film forming material for a silicon film.

  Next, the polysilane-modified silicon fine particles 13 are subjected to hydrogenation treatment. In this case, for example, chlorine containing aluminum polychloride and polysilane-modified silicon fine particles 13 having the polysilane 11 made of polydiphenylsilane bonded to the surface thereof in a solvent made of, for example, toluene having a water concentration of 10 ppm or less in which dissolved oxygen is previously substituted with Ar. A phenyl group is chlorinated by adding a hydrogenation catalyst and carrying out hydrogen chloride gas bubbling. Subsequently, the dissolved hydrogen chloride in the solvent is sufficiently replaced by Ar bubbling, and then a lithium aluminum hydride / ether solution is dropped and reacted for about 12 hours. Next, this solution is filtered to remove unreacted lithium aluminum hydride and its salt after the reaction, and the filtrate is purified by distillation to remove impurities.

  As a result, as shown in FIG. 1 (c), all the phenyl groups of the polysilane-modified silicon fine particles 13 (see FIG. 1 (b)) having polydiphenylsilane bonded to the surface thereof are all hydrogenated, and hydrogenated polysilane (hydrogenated) Polysilane-modified silicon fine particles (hydrogenated polysilane-modified silicon fine particles) 14 having (silicon) 11 'are generated. Here, by purifying by distillation, a toluene dispersion in which the isolated hydrogenated polysilane-modified silicon fine particles 14 are concentrated is obtained. However, all of the solvent may be volatilized. Further, even if Cl bonded to the surface of the silicon fine particles 12 remains by the hydrogenation treatment, this Cl is also hydrogenated. The produced hydrogenated polysilane-modified silicon fine particles 14 are used as a film forming material in a silicon film forming method described later.

  The diameter of the hydrogenated polysilane-modified silicon fine particles 14 is defined by the chain length of the silicon fine particles 12 and the hydrogenated polysilane 11 ′ bonded to the surface of the silicon fine particles 12. For this reason, the diameter of the hydrogenated polysilane-modified silicon fine particles 14 can be easily controlled by making polysilyl having a controlled chain length into a silyl anion from the beginning.

  As described above, according to such a method for producing polysilane-modified silicon fine particles, polysilane-modified silicon fine particles 13 are produced by adding silicon fine particles 12 to a liquid containing polysilane 11 having a terminal silyl anion. Then, hydrogenated polysilane-modified silicon fine particles 14 are produced by performing a hydrogenation process. Thereby, for example, a film forming material for forming a silicon film can be obtained by a coating method.

  Further, according to the method for producing the polysilane-modified silicon fine particles of the present embodiment, since the silicon fine particles 12 are produced by the synthesis method, the polysilane-modified silicon fine particles 13 and the hydrogenated polysilane-modified silicon fine particles 14 can be produced only by the synthesis method. Is possible.

  In the present embodiment, after producing polysilane-modified silicon fine particles 13 having polydiphenylsilane bonded to the surface, hydrogenation is performed to replace the phenyl group with hydrogen, thereby producing hydrogenated polysilane-modified silicon fine particles 14. However, from the beginning, hydrogenated polysilane (silicon hydride) may be converted into a silyl anion and bonded to the surface of the silicon fine particle 12 whose surface is modified with Cl. However, since the surface of the silicon fine particles 12 is also hydrogenated by performing the above hydrogenation treatment, it is possible to prevent Cl from remaining. Therefore, after the polysilane-modified silicon fine particles 13 having polydiphenylsilane bonded to the surfaces are produced, It is preferable to manufacture the hydrogenated polysilane-modified silicon fine particles 14 by performing a hydration treatment.

(Method for forming silicon film)
Next, a method for forming a silicon film using the hydrogenated polysilane-modified silicon fine particles 14 will be described with reference to FIG. First, as shown in FIG. 2A, hydrogenated polysilane-modified silicon fine particles 14 are dispersed in a solvent made of, for example, toluene. At this time, in the above-described method for producing the polysilane-modified silicon fine particles, concentrated hydrogenated polysilane-modified silicon fine particles 14 dispersed in toluene are obtained. Therefore, the concentration is appropriately adjusted with the solvent. This dispersion is applied onto a substrate (base) 21 made of, for example, a glass substrate to form a coating film 22. At this time, the minimum film thickness of the coating film 22 is defined to some extent by the diameter of the hydrogenated polysilane-modified silicon fine particles 14.

  Here, as a solvent in which the hydrogenated polysilane-modified silicon fine particles 14 are dispersed, in addition to toluene described above, n-pentane, n-hexane, n-heptane, n-octane, decane, dodecane, cyclohexane, cyclooctane, Hydrocarbon solvents such as styrene, dicyclopentane, benzene, xylene, cumene, durene, indene, tetrahydronaphthalene, decahydronaphthalene, squalane, diethyl ether, dipropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol ethyl Methyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, tetrahydrofuran tetrahydropyran, 1,2 Ether solvents such as diethoxyethane, bis (2-methoxyethyl) ether, p-dioxane, THF, and propylene carbonate, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylformamide, acetonitrile, dimethyl sulfoxide, chloride Examples include polar solvents such as methylene and chloroform. Of these, hydrocarbon solvents are preferred from the viewpoint of the stability of the dispersion described above. These solvents can be used alone or as a mixture of two or more.

  Next, the substrate 21 on which the coating film 22 is formed is heated. By performing the heat treatment, the hydrogenated polysilane 11 ′ (see FIG. 1C) bonded to the surface of the hydrogenated polysilane-modified silicon fine particles 14 changes to amorphous silicon or polysilicon. This heat treatment is performed in the range of 120 ° C. to 1000 ° C. When forming amorphous silicon from the hydrogenated polysilane 11 ′, the temperature is 120 ° C. or higher and lower than 550 ° C., and when forming polysilicon, 550 ° C. or higher. It will be performed at the temperature of. Here, the hydrogenated polysilane 11 ′ is changed to amorphous silicon 23 ′, and the substrate 21 is heated at 450 ° C., for example. At this time, since the silicon fine particles 12 composed of single crystal silicon remain, as shown in FIG. 2B, the silicon film 23 in a state where the crystalline silicon fine particles 12 are contained in the amorphous silicon 23 ′ is formed. It is formed.

  At this time, the light V is irradiated toward the coating film 22 together with the heat treatment. This is preferable because the reaction of forming amorphous silicon 23 'from hydrogenated polysilane 11' is promoted. Here, as the light source of the light V, for example, a mercury xenon lamp is used. Further, the irradiation wavelength range of the light V is preferably 200 nm or more and 450 nm or less, and more preferably both light having a wavelength of 200 nm or more and less than 320 nm and light having a wavelength of 320 nm or more and 450 nm or less are irradiated. By irradiating light with a wavelength of 200 nm or more and less than 320 nm, the Si—Si bond and Si—H bond of the hydrogenated polysilane portion are cut. Moreover, by irradiating light with a wavelength of 320 nm or more and 450 nm or less, the Si—Si bond and the Si—H bond are recombined to form amorphous silicon 23 ′.

  The irradiation with the light V may be performed after the coating film 22 (see FIG. 2A) is formed on the substrate 21, and the polysilane-modified silicon fine particles 14 are dispersed before coating on the substrate 21. You may perform with respect to the dispersion liquid of a state. In addition, after the light V is irradiated at the stage of the dispersion to form the coating film 22 on the substrate 21, the light V may be further irradiated toward the coating film.

  Further, laser light may be irradiated as the light V. In this case, since the laser beam irradiation also serves as a heat treatment, the temperature of the heat treatment may be about 120 ° C.

  Here, an example in which both the heat treatment and the light V irradiation are performed on the substrate 21 on which the coating film 22 is formed will be described. However, the silicon film 23 is formed only by the heat treatment. Further, when the irradiation energy of the light V is high, it is possible to form the amorphous silicon 23 ′ from the hydrogenated polysilane 11 ′ of the polysilane-modified silicon fine particles 14 only by the irradiation of the light V to form the silicon film 23. is there. In this case, after the coating film 22 is formed on the substrate 21, only the irradiation with the light V is performed without performing heat treatment. When the silicon film 23 is formed only by irradiation with the light V, the silicon film 23 can be formed not only by the coating method but also by the dipping method. For example, a cell made of quartz having a high light transmittance in the above wavelength range is filled with a dispersion liquid in which polysilane-modified silicon fine particles 14 are dispersed, and light V is irradiated through the quartz glass using, for example, a spot UV irradiator. Then, the silicon film 23 is formed only in the irradiation region of the light V on the inner wall of the cell. However, as described above, it is preferable to perform both the heat treatment and the irradiation with the light V because the silicon film 23 can be reliably formed.

  As described above, the silicon film 23 generated by performing heat treatment and light irradiation on the coating film 22 on the substrate 21 is amorphous silicon in a state where the silicon fine particles 12 are covered with the hydrogenated polysilane 11 ′ bonded to the silicon fine particles 12. Since 23 ′ is formed, defects are unlikely to occur at the interface between the amorphous silicon 23 ′ and the silicon fine particles 12.

  The silicon film 23 exhibits the properties of an amorphous silicon film when the chain length of the hydrogenated polysilane 11 ′ is long and the diameter of the silicon fine particles 12 is smaller than the film thickness of the silicon film 23. On the other hand, when the chain length of the hydrogenated polysilane 11 ′ is short and the diameter of the silicon fine particles 12 is larger than the thickness of the formed silicon film 23, the characteristics of the film in which amorphous silicon and crystalline silicon are mixed are obtained. Show.

  Next, heat treatment at 550 ° C. or more and 1000 ° C. or less is performed on the substrate 21 on which the silicon film 23 is formed, which has been described with reference to FIG. Here, for example, heat treatment at 1000 ° C. is performed. As a result, as shown in FIG. 2C, the amorphous silicon 23 ′ (see FIG. 2B) is crystallized to become polysilicon 24 ′, and crystalline silicon fine particles 12 in the polysilicon 24 ′. As a result, the polysilicon film 24 is formed.

  Here, the polysilicon film 24 is formed by further performing heat treatment on the substrate 21 on which the silicon film 23 is formed, but the coating film 22 described with reference to FIG. 2A is formed. Even when the substrate 21 in the state is irradiated with the heat treatment at 550 ° C. or more and 1000 ° C. or less and the light V in the wavelength range described above, the polysilicon film 24 is formed. In this case, the hydrogenated polysilane 11 ′ of the polysilane-modified silicon fine particles 14 is changed to polysilicon 24 ′ by the heat treatment.

  As described above, according to the silicon film forming method of the present embodiment, the dispersion liquid containing the polysilane-modified silicon fine particles 14 is applied on the substrate 21 to form the coating film 22, irradiated with the light V and 450 ° C. By performing this heat treatment, the hydrogenated polysilane 11 ′ of the polysilane-modified silicon fine particles 14 becomes amorphous silicon 23 ′. Therefore, the silicon film 23 containing the silicon fine particles 12 in the amorphous silicon 23 'is formed. Further, the polysilicon film 24 can be formed by performing a heat treatment at 1000 ° C. on the substrate 21 on which the silicon film 23 is formed. Since the minimum film thickness of the silicon film 23 and the polysilicon film 24 formed as described above is regulated to some extent by the diameter of the polysilane-modified silicon fine particles 14, the film thickness can be easily controlled. The obtained silicon film is suitably used as a silicon film for LSIs, thin film transistors, photoelectric conversion devices and photoreceptors.

  In the above embodiment, the silicon film forming method using the hydrogenated polysilane-modified silicon fine particles 14 has been described. However, the present invention is applicable even if the side chain of the polysilane is an atom other than hydrogen or a substituent. It is. For example, even if the polysilane-modified silicon fine particles 13 in which the polydiphenylsilane described with reference to FIG. 1B is bonded to the silicon fine particles 12 are used, the silicon film 23 is formed. In this case, a dispersion liquid in which the polysilane-modified silicon fine particles 13 are dispersed in a solvent is applied onto the substrate to form a coating film. Next, light irradiation or heat treatment is performed on the substrate on which the coating film is formed. At this time, it is effective to perform both light irradiation and heat treatment by laser light irradiation, whereby the side chain portion (here, phenyl group) of polysilane is decomposed and evaporated. However, in this case, atoms or substituents derived from the side chain may remain in the silicon film 23, and these may remain.

  An example of the above-described embodiment will be specifically described. Here, an example of a method for producing polysilane-modified silicon fine particles by the same method as the embodiment described with reference to FIG. 1 and a method for forming a silicon film using the polysilane-modified silicon fine particles will be described.

Example 1
First, in an Ar glove box, a dropping funnel, a bubbling capillary, and an exhaust pipe were attached, and a 300 ml four-necked mantle flask containing a stirrer was preliminarily substituted with Ar by bubbling Ar with a water concentration of 10 ppm or less. 150 ml of THF and Li were added. Next, with Ar bubbling and stirring at 0 ° C., 40 ml of silicon compound composed of liquid diphenyldichlorosilane was added from the dropping funnel, and stirring was continued for 12 hours until the lithium disappeared completely after the dropping. It was. Thereafter, unreacted substances and by-products were removed, and as shown in FIG. 1 (a), polysilane 11 having a terminal converted to silyl anion was obtained.

On the other hand, in an Ar glove box, a dropping funnel was attached, and a 3-neck flask containing a stirrer was preliminarily replaced with Ar by bubbling Ar to 70 ppm 1,2-dimethoxyethane having a water concentration of 10 ppm or less, 3 g of naphthalene, Sodium 0.7g was added and stirred. On the other hand, silicon tetrachloride (SiCl ₄ ) was dissolved in 1,2-dimethoxyethane having a water concentration of 10 ppm or less in which dissolved oxygen was substituted with Ar by Ar bubbling in advance.

Next, from the dropping funnel, the 1,2-dimethoxyethane in which silicon tetrachloride (SiCl ₄ ) was dissolved was dropped into 1,2-dimethoxyethane to which naphthalene and sodium were added in a stirred state, and 12 Reacted for hours. Thereafter, by removing naphthalene, sodium, and sodium chloride, silicon fine particles 12 having Cl bonded to the surface were generated.

  Next, 1,2-dimethoxyethane in which the silicon fine particles 12 are dispersed and the above-described solution in which the silyl anionized Li-adduct of polydiphenylsilane is dissolved in THF are mixed and sufficiently reacted. Thereafter, when the solution was dropped into a beaker filled with cold water, a precipitate was obtained. This was recovered, and the precipitate was washed with cyclohexane and analyzed by IR, 1H-NMR, and 29Si-NMR. As a result, it was confirmed that polysilane-modified silicon fine particles 12 having polydiphenylsilane bonded to the surface were obtained.

  Next, the above-described polysilane-modified silicon fine particles 12 having polydiphenylsilane bonded to the surface and aluminum chloride were added to toluene having a water concentration of 10 ppm or less in which dissolved oxygen was substituted with Ar by Ar bubbling, and hydrogen chloride gas bubbling was performed. Subsequently, dissolved hydrogen chloride in toluene was sufficiently replaced by Ar bubbling, and then a lithium aluminum hydride / ether solution was dropped and reacted for 12 hours. The solution was then filtered and the reaction product was purified by distillation. When the purified reaction product was analyzed by 1H-NMR and 29Si-NMR, it was confirmed that hydrogenated polysilane-modified silicon fine particles 14 in which all phenyl groups were hydrogenated were generated.

(Example 2)
As described in the embodiment with reference to FIGS. 2A to 2B, the hydrogenated polysilane-modified silicon fine particles 14 obtained in Example 1 are applied on the substrate 21 to form the coating film 22. The substrate 21 on which the coating film 22 was formed was heat-treated at 450 ° C., and the coating film 22 was irradiated with light V in an irradiation wavelength region of 200 nm to 450 nm as in the embodiment. As a result, a yellow-brown film having a metallic luster was formed on the surface of the substrate 21. Measurement of the optical band gap of the film is 1.8 eV, also, in the Raman spectrum, a broad peak assignable to amorphous silicon is observed near 480 cm ^-1, the crystalline silicon in the vicinity of 510 cm ^-1 An attributed sharp peak was observed.

(Example 3)
As described in the embodiment with reference to FIG. 2C, the substrate 21 on which the silicon film 23 obtained in Example 1 was formed was subjected to heat treatment at 1000 ° C. When the optical band gap of this film was measured, it was 1.7 eV, and in the Raman spectrum, a sharp peak attributed to polysilicon was observed in the vicinity of 510 cm ⁻¹ .

It is a typical process drawing for explaining an embodiment concerning a manufacturing method of polysilane modification silicon particulates of the present invention. It is manufacturing process sectional drawing for demonstrating embodiment which concerns on the formation method of the silicon film of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Polysilane, 11 '... Hydrogenated polysilane, 12 ... Silicon fine particle, 13 ... Polysilane modified silicon fine particle, 14 ... Hydrogenated polysilane modified silicon fine particle, 21 ... Substrate, 23 ... Silicon film, V ... Light

Claims (9)

A polysilane-modified silicon fine particle characterized by producing polysilane-modified silicon fine particles in which the polysilane is bonded to the surface of the silicon fine particle by adding silicon fine particles to a liquid containing polysilane having a terminal silyl anion. Production method. In the manufacturing method of the polysilane modification silicon fine particles according to claim 1,
The silicon fine particle has a halogen atom bonded to the surface thereof, and the polysilane-modified silicon fine particle is produced by substituting the halogen atom with the polysilane having an end converted to a silyl anion. Manufacturing method. In the manufacturing method of the polysilane modification silicon fine particles according to claim 1,
A method for producing polysilane-modified silicon fine particles, wherein the silicon fine particles produced by a synthesis method are used. In the manufacturing method of the polysilane modification silicon fine particles according to claim 1,
The polysilane is composed of polydiphenylsilane,
The polysilane modified silicon, wherein the polydiphenylsilane is bonded to the surface of the silicon particle to produce the polysilane modified silicon particle, and then the phenyl group of the polydiphenylsilane bonded to the silicon particle is hydrogenated. A method for producing fine particles. In a method of forming a silicon film on the surface of a substrate,
Forming a silicon film on the surface of the substrate by performing light irradiation or heat treatment in a state in which the surface of the substrate is in contact with a liquid containing polysilane-modified silicon particles in which polysilane is bonded to the surface of the silicon particles. A method for forming a silicon film. The method of forming a silicon film according to claim 5,
A liquid containing the polysilane-modified silicon fine particles is applied to the surface of the base to form a coating film, and the light irradiation or the heat treatment is performed on the base in a state where the coating film is formed. A method of forming a silicon film, comprising forming the silicon film on a surface. The method of forming a silicon film according to claim 5,
The silicon film is formed on the surface of the substrate by performing both the light irradiation and the heat treatment. The method of forming a silicon film according to claim 5,
The method of forming a silicon film, wherein the polysilane is silicon hydride. The method of forming a silicon film according to claim 5,
The method for forming a silicon film, wherein the silicon film is an amorphous silicon film, a polysilicon film, or a film in which crystalline silicon and amorphous silicon are mixed.

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