JPWO2020116340A1 - Manufacturing method of semiconductor elements and manufacturing method of solar cells - Google Patents

Abstract

The present invention makes it possible to manufacture a solar cell having a selective emitter structure by a simple method without requiring a complicated device, and a method for manufacturing a semiconductor element having excellent in-plane uniformity of impurity concentration, and An object of the present invention is to provide a method for manufacturing a solar cell.
The present invention for achieving the above object is a method for manufacturing a semiconductor device that forms an impurity diffusion layer region of the same type on a semiconductor substrate at two or more levels of different impurity concentrations, of which at least one level or more of impurity diffusion. The layer region is a step of applying the impurity diffusion composition (a) to the semiconductor substrate to partially form the impurity diffusion composition film (b) and heating it to diffuse the impurities to the semiconductor substrate to diffuse the impurity diffusion layer. The impurity diffusion composition (a) is formed by a method including a step of forming the region (c), and contains (a-1) a polymer of a silane compound having a specific structure, and (a-2) an impurity diffusion component. This is a method for manufacturing a semiconductor element.

Description

The present invention relates to a method for manufacturing a semiconductor element and a method for manufacturing a solar cell, and particularly relates to a method for manufacturing a highly efficient semiconductor element and a method for manufacturing a solar cell.

In the production of a conventional solar cell having a pn junction, a pn junction is formed by diffusing an n-type impurity into a p-type semiconductor substrate such as silicon to form an n-type diffusion layer.

In recent years, a solar cell having a selective emitter structure proposed for lowering the contact resistance with an electrode and suppressing carrier recombination has been disclosed (Non-Patent Document 1). For example, in a solar cell having a selective emitter structure based on an n-type silicon substrate, a high-concentration p-type diffusion layer (p ⁺⁺ layer) is formed directly under the electrode in the p-type diffusion layer on the light receiving surface side, and other than directly under the electrode. A low-concentration to medium-concentration p-type diffusion layer (p ⁺ layer) is formed on the light receiving surface of the above. It is known that in order to form a selective emitter structure, a complicated process combining a plurality of diffusions and partial etching by masking is required (Patent Document 1). Further, for the purpose of simplifying the process, a method of diffusing impurities by separately applying a diffusing agent having a plurality of impurity concentrations to the substrate by an inkjet method (Patent Document 2), and selecting on the substrate using a coating liquid containing an impurity diffusing component. A method of forming a plurality of impurity concentration regions by forming a pattern and heat-treating the patterned substrate in a doping gas atmosphere (Patent Documents 3, 4, 5), and using a coating liquid containing an impurity diffusion component. A method of forming a plurality of impurity concentration regions by selectively forming a pattern on a substrate and utilizing an outdiffusion phenomenon from the pattern by heat treatment (Patent Documents 6 and 7) has been proposed.

Japanese Unexamined Patent Publication No. 2004-193350 Japanese Unexamined Patent Publication No. 2004-221149 Japanese Unexamined Patent Publication No. 2012-134571 Japanese Unexamined Patent Publication No. 2015-50357 Japanese Unexamined Patent Publication No. 2006-310368 JP-A-2017-22350 Special Table 2002-503390

E. Lee et. Al., “Exceeding 19% efficient 6 inch screen printed crystalline silicon solar cells with selective emitter”, Renewable Energy, Volume 42 (June 2012), p.95-99

However, in the method described in Patent Document 1, steps for pattern formation and etching are required to form the selective emitter structure, and the number of steps tends to increase. Further, the inkjet method described in Patent Document 2 requires a dedicated device having a plurality of heads, and control of injection from each head becomes complicated. Further, the diffusion pastes described in Patent Documents 3 to 5 have a problem that the outdiffusion concentration of impurities from the paste film is insufficiently suppressed, so that the diffusion concentration of impurities in the portion other than the pattern forming portion varies widely. Further, the methods described in Patent Documents 6 and 7 have a problem that it is difficult to control out-diffusion, and there is also a large variation in impurity diffusion concentration in a portion other than the pattern-forming portion.

The present invention has been made in view of the above-mentioned conventional problems, and enables a solar cell having a selective emitter structure to be manufactured by a simple method without requiring a complicated device, and has an in-plane impurity concentration. It is an object of the present invention to provide a method for manufacturing a semiconductor element having excellent uniformity and a method for manufacturing a solar cell.

In order to solve the above problems, the method for manufacturing a semiconductor device of the present invention has the following configuration. That is, it is a method for manufacturing a semiconductor element that forms the same type of impurity diffusion layer region on a semiconductor substrate at two or more levels of different impurity concentrations, of which at least one level or more of the impurity diffusion layer region is an impurity diffusion composition. A step of applying (a) to a semiconductor substrate to partially form an impurity diffusion composition film (b) and a step of heating it to diffuse impurities to the semiconductor substrate to form an impurity diffusion layer region (c). (A-1) Manufacture of a semiconductor element containing (a-1) a polymer of a silane compound represented by the following general formula (1), and (a-2) an impurity diffusion component. The method.

(In the general formula (1), R ¹ and R ² are hydroxyl groups, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, and acyloxy having 2 to 6 carbon atoms. It represents either a group or an aryl group having 6 to 15 carbon atoms, and the plurality of R ¹ and R ² may be the same or different, respectively. L _{1 represents an integer of 1 to 10000.)}

According to the present invention, a solar cell having a selective emitter structure can be manufactured by a simple method without requiring a complicated device, and a method for manufacturing a semiconductor element having excellent in-plane uniformity of impurity concentration, and , A method for manufacturing a solar cell can be provided.

It is a process sectional view which shows an example of the manufacturing method of the semiconductor element of this invention. It is a process sectional view which shows another example of the manufacturing method of the semiconductor element of this invention. It is a figure which shows the screen printing pattern and the sheet resistance value measurement point used in the Example of this invention.

Hereinafter, the impurity diffusion compositions (a) and (d) used in the present invention will be described first, and then a method for producing a suitable semiconductor element (selective emitter structure) will be described with reference to the drawings. The following embodiments are examples, and the present invention is not limited to these embodiments.
<Impurity diffusion composition (a)>
The impurity diffusion composition (a) used in the present invention contains (a-1) a polymer of a silane compound represented by the following general formula (1) as an essential component.

In the general formula (1), R ¹ and R ² are hydroxyl groups, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, and acyloxy groups having 2 to 6 carbon atoms. , Which represents any of the aryl groups having 6 to 15 carbon atoms, and the plurality of R ¹ and R ² may be the same or different, respectively. l ₁ represents an integer of 1 to 10000. From the viewpoint of the toughness of the film after film formation and the uniformity of the coating film thickness, it is preferably 5 to 9000, more preferably 10 to 8000.

Alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkenyl group having 2 to 10 carbon atoms, acyloxy group having 2 to 6 carbon atoms, and carbon number of carbon atoms in ^{R 1} and R ² of the general formula (1). The aryl groups 6 to 15 may be either unsubstituted or substituted, and can be selected according to the characteristics of the impurity diffusion composition.

As a substituent of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, and the acyloxy group having 2 to 6 carbon atoms, the hydrocarbon is an amino group, a mercapto group, a hydroxyl group, a glycidyl group, a glycidyloxy group, and the like. A structure substituted with an isocyanate group is preferable. The number of substitutions is preferably 1 to 3, and more preferably 1.

As a substituent of the alkenyl group having 2 to 10 carbon atoms, the hydrocarbon has a structure in which the hydrocarbon is substituted with an amino group, a mercapto group, a hydroxyl group, a glycidyl group, a glycidyloxy group, an isocyanate group, and a carbonyloxyalkyl group having 2 to 8 carbon atoms. Is preferable. The number of substitutions is preferably 1 to 3, and more preferably 1.

Examples of the substituent of the aryl group having 6 to 15 carbon atoms include an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and 2 to 5 carbon atoms in the aromatic ring. An acyloxy group, a carbonyloxyalkyl group having 2 to 7 carbon atoms, an amino group, a mercapto group, a hydroxyl group, a glycidyl group, a glycidyloxy group, an isocyanate group bonded structure, or an alkyl group having 1 to 3 carbon atoms from an aromatic ring. A structure in which an acyloxy group, an amino group, a mercapto group, a hydroxyl group, a glycidyl group, a glycidyloxy group, and an isocyanate group having 2 to 5 carbon atoms are bonded to each other is preferable. The number of substitutions is preferably 1 to 3, and more preferably 1.

Specific examples of alkyl groups having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, n-hexyl group, trifluoromethyl group, 3, Examples thereof include a 3,3-trifluoropropyl group, a 3-glycidoxypropyl group, a 3-aminopropyl group, a 3-mercaptopropyl group, and a 3-isocyantic propyl group.

Specific examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group and the like.

Specific examples of the alkenyl group having 2 to 10 carbon atoms include a vinyl group, a 3-acryloxypropyl group, a 3-methacryloxypropyl group and the like.

Specific examples of the acyloxy group having 2 to 6 carbon atoms include an acetyloxy group.

Specific examples of the aryl group having 6 to 15 carbon atoms include a phenyl group, a tolyl group, a p-hydroxyphenyl group, a p-styryl group, a p-methoxyphenyl group, a 1- (p-hydroxyphenyl) ethyl group, and 2-. Examples thereof include a (p-hydroxyphenyl) ethyl group, a 4-hydroxy-5- (p-hydroxyphenylcarbonyloxy) pentyl group, a naphthyl group and the like.

From the viewpoint of facilitating suppression of outdiffusion from the impurity diffusion composition ^{, at least one of R 1} and R ² is an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and 2 to 6 carbon atoms. It is preferable that it represents any of an acyloxy group and an aryl group having 6 to 15 carbon atoms.

More preferably, R ¹ represents any one of an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, and an aryl group having 6 to 15 carbon atoms. R ² represents either a hydroxyl group or an alkoxy group having 1 to 6 carbon atoms.

From the viewpoint of facilitating suppression of outdiffusion from the impurity diffusion composition, the polymer of the silane compound is preferably a polymer of the silane compound represented by the following general formula (2).

In the general formula (2), R ³ represents an aryl group having 6 to 15 carbon atoms, and the plurality of R ³ may be the same or different. R ⁴ is a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an aryl group having from 6 to 15 carbon atoms represents either be with or different plural R ⁴ are the same, respectively. R ⁵ and R ⁶ represent any one of a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and an acyloxy group having 2 to 6 carbon atoms. R ⁵ and R ^{6 of the above} may be the same or different, respectively. n ₁ and m ₁ represent an integer of _{1 to 9999, n 1} + m ₁ is an integer of 2 to 10000, and n ₁ : m ₁ = 95: 5 to 25:75. From the viewpoint of the toughness of the film after film _{formation, the preferable range (n 1} + m ₁ ) is 5 to 9000, and more preferably 10 to 8000.

^{The aryl group having 6 to 15 carbon atoms in R 3} of the general formula (2) may be an unsubstituted or substituted product, and can be selected according to the characteristics of the impurity diffusion composition. Preferred substitution structures include those similar to those in ^{R 1} and R ^2. Specific examples of the aryl group having 6 to 15 carbon atoms include those similar to those in ^{R 1} and R ^2.

Alkyl group having 1 to 6 carbon atoms for ^{R 4} in the general formula (2), an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, 6 to 15 carbon atoms The aryl group of can be either an unsubstituted or substituted product, and can be selected according to the characteristics of the impurity diffusion composition. Preferred substitution structures include those similar to those in ^{R 1} and R ^2. Specific examples of these include those similar to those in ^{R 1} and R ^2.

The alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, the alkenyl group having 2 to 10 carbon atoms, and the acyloxy group having 2 to 6 carbon atoms in ^{R 5} and R ⁶ of the general formula (2) are all. Either a non-substituted product or a substituted product may be used, and can be selected depending on the characteristics of the impurity diffusion composition. Preferred substitution structures include those similar to those in ^{R 1} and R ^2. Specific examples of these include those similar to those in ^{R 1} and R ^2.

Specific examples of the organosilane that can be used as a raw material for the polymer of the silane compound represented by the general formula (1) include tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane and tetraacetoxysilane, and methyltrimethoxysilane. Methyltriethoxysilane, methyltriisopropoxysilane, methyltri n-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri n-butoxysilane, n-propyltrimethoxysilane, n-propyltri Ethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-Methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3-aminopropyltri Trifunctional silanes such as methoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, dimethyldimethoxysilane, dimethyl Examples thereof include bifunctional silanes such as diethoxylan, dimethyldiacetoxysilane, din-butyldimethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, and (3-glycidoxypropyl) methyldiethoxysilane. These organosilanes may be used alone or in combination of two or more. Among these organosilanes, trifunctional silanes are preferably used from the viewpoint of facilitating suppression of outdiffusion from the impurity diffusion composition.

Specific examples of the organosilane that can be used as a raw material for the unit having ^{R 3} and R ⁴ of the silane compound represented by the general formula (2) include phenyltrimethoxysilane, phenyltriethoxysilane, and p-hydroxyphenyltrimethoxy. Silane, p-tolyltrimethoxysilane, p-styryltrimethoxysilane, p-methoxyphenyltrimethoxysilane, 1- (p-hydroxyphenyl) ethyltrimethoxysilane, 2- (p-hydroxyphenyl) ethyltrimethoxysilane, 4-Hydroxy-5- (p-Hydroxyphenylcarbonyloxy) Pentilt Remethoxysilane, Diphenyldimethoxysilane, 1-Nufftilt Remethoxysilane, 2-Nufftilt Remethoxysilane, 1-Nufftilt Reethoxysilane, 2-Nufftilt Reethoxysilane , Anthracentrimethoxysilane is preferably used. Among these, those having a monocyclic aryl group such as phenyl are more preferable than those having a polycyclic aryl group such as naphthalene type and anthracene type from the viewpoint of cost.

^{Specific examples of the organosilane that can be used as a raw material for the unit having R 5} and R ⁶ of the general formula (2) are the same as those of the organosilane that is the raw material of the polymer of the silane compound represented by the general formula (1). Can be mentioned. Among them, trifunctional silane is preferably used from the viewpoint of facilitating the suppression of outdiffusion from the impurity diffusion composition.

The polymer of the silane compound represented by the general formula (2) is a polysiloxane in which the unit containing an aryl group having 6 to 15 carbon atoms is 25 to 95 mol% in terms of Si atom. That is, n ₁ : m ₁ = 95: 5 to 25:75. Within this range, the effects of suppressing outdiffusion of the impurity diffusion component and reducing the organic residue when the impurity diffusion component is removed after the heat treatment are improved. Further, within this range, even in the impurity diffusion composition to which a thermal decomposition component such as a thickener is added, it becomes possible to fill the vacancies generated by the thermal decomposition due to the reflow effect of siloxane, and the vacancies can be filled. It is possible to form a dense film with less heat. Therefore, it is not easily affected by the atmosphere at the time of diffusion, and a high masking property against other impurities can be obtained.

The terminal group shall be any of hydrogen, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, and an alkenyl group having 2 to 10 carbon atoms. Is preferable.

The polymer of the silane compound represented by the general formula (2) may contain each of the constituent components in the above-mentioned predetermined ratio, and may be a block copolymer or a random copolymer.

From the viewpoint of suppressing outdiffusion and further improving the masking property, the unit containing an aryl group having 6 to 15 carbon atoms is more preferably 35 mol% or more, further preferably 40 mol% or more. Further, in order not to generate a residue without being affected by the atmosphere and the film thickness, the amount of the aryl group-containing unit is preferably 80 mol% or less. That is, n ₁ : m ₁ = 80: 20 to 35:65 is more preferable, and n ₁ : m ₁ = 80: 20 to 40:60 is even more preferable.

The polymer of the silane compound represented by the general formulas (1) and (2) is obtained by, for example, hydrolyzing the organosilane compound and then subjecting the hydrolyzate to a condensation reaction in the presence of a solvent or in the absence of a solvent. Obtainable. Various conditions of the hydrolysis reaction, such as acid concentration, reaction temperature, reaction time, etc., can be appropriately set in consideration of the reaction scale, the size, shape, etc. of the reaction vessel. For example, an organosilane compound in a solvent. It is preferable to add an acid catalyst and water to the mixture over 1 to 180 minutes and then react at room temperature to 110 ° C. for 1 to 180 minutes. By carrying out the hydrolysis reaction under such conditions, a rapid reaction can be suppressed. The reaction temperature is more preferably 30 to 130 ° C.

The hydrolysis reaction is preferably carried out in the presence of an acid catalyst. Acid catalysts include hydrogen halide-based inorganic acids such as hydrochloric acid, hydrobromic acid, and hydroiodic acid, sulfuric acid, nitrate, phosphoric acid, hexafluorophosphate, hexafluoroantimonic acid, boric acid, and tetrafluoroboric acid. Other inorganic acids such as chromic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, sulfonic acid such as trifluoromethanesulfonic acid, acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, Carous acids such as tartrate acid, pyruvate, citric acid, succinic acid, fumaric acid and malic acid can be exemplified. In the present invention, the acid catalyst preferably contains atoms other than silicon, hydrogen, carbon, oxygen, nitrogen, and phosphorus as much as possible from the viewpoint of doping property, and a phosphoric acid, formic acid, acetic acid, or carboxylic acid-based acid catalyst is used. Is preferable.
Of these, phosphoric acid is preferable.

The preferable content of the acid catalyst is preferably 0.1 part by mass to 5 parts by mass with respect to 100 parts by mass of the total organosilane compound used in the hydrolysis reaction. By setting the amount of the acid catalyst in the above range, the hydrolysis reaction can be easily controlled so as to proceed sufficiently and sufficiently.

The solvent used for the hydrolysis reaction of the organosilane compound and the condensation reaction of the hydrolyzate is not particularly limited, and can be appropriately selected in consideration of the stability, coatability, volatility and the like of the resin composition. Further, two or more kinds of solvents may be combined, or the reaction may be carried out without a solvent. Specific examples of the solvent include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, 1-methoxy-2-propanol, pentanol, 4-methyl-2-pentanol, 3-methyl-2-. Alcohols such as butanol, 3-methyl-3-methoxy-1-butanol, 1-t-butoxy-2-propanol, diacetone alcohol; glycols such as ethylene glycol and propylene glycol; ethylene glycol monomethyl ether, ethylene glycol mono Ethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol t-butyl ether, propylene glycol n-butyl ether ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethyl ether, diethylene glycol methyl Ethers such as ethyl ether, dipropylene glycol-n-butyl ether, dipropylene glycol monomethyl ether, diisopropyl ether, din-butyl ether, diphenyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, ethylene glycol monobutyl ether; methyl ethyl ketone, acetylacetone, methylpropyl Ketones such as ketones, methylbutyl ketones, methylisobutylketones, diisobutylketones, cyclopentanones, 2-heptanones, diisobutylketones, cyclohexanones, cycloheptanones; amides such as dimethylformamides and dimethylacetamides; isopropyl acetates, ethyl acetates, Propyl acetate, butyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate , 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, butyl diglycol acetate, 1,3-butylene glycol diacetate, ethyl diglycol acetate, dipropylene glycol methyl Acetates such as ether acetate, methyl lactate, ethyl lactate, butyl lactate, triacetylglycerin; aromatics or fats such as toluene, xylene, hexane, cyclohexane, ethyl benzoate, naphthalene, 1,2,3,4-tetrahydronaphthalene. Group hydrocarbons, γ-butyrolactone, N-methyl-2-pyrrolidone, N, N-dimethylimidazolidinone, dimethylsulfoxide, propylene carbonate and the like can be mentioned.

In the present invention, diethylene glycol methyl ethyl ether (boiling point 176 ° C.), ethylene glycol monoethyl ether acetate (boiling point 156.4 ° C.), ethylene glycol monomethyl ether acetate (boiling point 145 ° C.), methyl lactate from the viewpoint of solubility and printability. (Boiling point 145 ° C.), Ethyl lactate (boiling point 155 ° C.), Diacetone alcohol (boiling point 169 ° C.), Propylene glycol monomethyl ether acetate (boiling point 145 ° C.), 3-methoxy-3-methyl-1-butanol (boiling point 174 ° C.) , Dipropylene glycol monomethyl ether (boiling point 188 ° C), dipropylene glycol-n-butyl ether (boiling point 229 ° C), γ-butyrolactone (boiling point 204 ° C), diethylene glycol monoethyl ether acetate (boiling point 217 ° C), butyl diglycol acetate (boiling point 217 ° C) 246 ° C.), ethyl acetoacetate (181 ° C.), N-methyl-2-pyrrolidone (204 ° C.), N, N-dimethylimidazolidinone (226 ° C.), dipropylene glycol methyl ether acetate (213 ° C.) ° C.), 1,3-butylene glycol diacetate (boiling point 232 ° C.), diisobutylketone (boiling point 168 ° C.), propylene glycol t-butyl ether (boiling point 151 ° C.), propylene glycol n-butyl ether (boiling point 170 ° C.) are preferably exemplified. be able to.

When a solvent is produced by the hydrolysis reaction, it can be hydrolyzed without a solvent. After completion of the reaction, it is also preferable to add a solvent to adjust the concentration to an appropriate level as the resin composition. Further, depending on the purpose, after hydrolysis, an appropriate amount of the produced alcohol or the like may be distilled off and removed under heating and / or reduced pressure, and then a suitable solvent may be added.

The amount of the solvent used in the hydrolysis reaction is preferably 80 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the total organosilane compound. By setting the amount of the solvent in the above range, the hydrolysis reaction can be easily controlled so as to proceed sufficiently and sufficiently. The water used for the hydrolysis reaction is preferably ion-exchanged water. The amount of water can be arbitrarily selected, but it is preferably used in the range of 1.0 to 4.0 mol with respect to 1 mol of Si atom.

The impurity diffusion composition (a) used in the present invention contains (a-2) an impurity diffusion component for forming an impurity diffusion layer in a semiconductor substrate. The n-type impurity diffusion component is preferably a compound containing a Group 15 element, and more preferably a phosphorus compound. The p-type impurity diffusion component is preferably a compound containing elements of the 13th group, and more preferably a boron compound.

When the impurity diffusion composition (a) is used in the method for producing a semiconductor element of the present invention, a diffusion layer of the same type of impurities having different concentrations is heated by gas, coating, etc. in the region where the impurity diffusion layer region (c) is not formed. When formed by diffusion, there is an advantage that the diffusion of the impurity diffusion layer region (c) proceeds more than simply adding only the same thermal history. It is speculated that this is due to the additional supply of impurities of the same type to the impurity diffusion layer region (c). This effect is particularly noticeable in p-type impurities. As a result, there is an advantage that the treatment conditions for obtaining the same diffusion layer state can be made milder.

Phosphoric compounds include diphosphoric pentoxide, phosphoric acid, polyphosphoric acid, methyl phosphate, dimethyl phosphate, trimethyl phosphate, ethyl phosphate, diethyl phosphate, triethyl phosphate, propyl phosphate, dipropyl phosphate, and phosphoric acid. Phosphate esters such as tripropyl, butyl phosphate, dibutyl phosphate, tributyl phosphate, phenyl phosphate, diphenyl phosphate, triphenyl phosphate, methyl phosphite, dimethyl phosphite, trimethyl borophosphate, sub Ethyl phosphate, diethyl phosphite, triethyl phosphite, propyl phosphite, dipropyl phosphite, tripropyl phosphite, butyl phosphite, dibutyl phosphite, tributyl phosphite, phenyl phosphite, Examples thereof include phosphite esters such as diphenyl phosphite and triphenyl phosphite. Of these, phosphoric acid, diphosphorus pentoxide or polyphosphoric acid is preferable from the viewpoint of doping property.

Examples of the boron compound include boric acid, diboron trioxide, methylboronic acid, phenylboronic acid, trimethyl borate, triethyl borate, tripropyl borate, tributyl borate, trioctyl borate, triphenyl borate and the like. can.

The impurity diffusion composition (a) used in the present invention may contain a binder resin in addition to the polymer of the silane compound. Preferred specific examples include polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, polysulfone, cellulose ether, carboxymethyl cellulose, hydroxyethyl cellulose, ethyl cellulose, gelatin, starch, dextrin, poly (meth) acrylic acid, poly (meth) acrylate, and the like. Examples include, but are not limited to, polydimethylaminoethyl (meth) acrylate, polybutadiene, polystyrene, polybutyral and the like. These can be used alone or in combination of two or more.

When the polymer of the (a-1) silane compound in the impurity diffusion composition (a) is a polymer of the silane compound represented by the general formula (2), a particularly preferable resin has a (a-3) degree of saponification of 20. Polyvinyl alcohols in an amount of mol% or more and less than 50 mol% can be mentioned. Polyvinyl alcohol is a component for forming a complex with (a-2) an impurity diffusion component, particularly a p-type impurity diffusion component, and forming a uniform film at the time of coating. By setting the degree of saponification of polyvinyl alcohol to 20% or more, the complex stability with the (a-2) impurity diffusion component is enhanced, and the diffusibility and diffusion uniformity are further improved. Further, by setting the degree of saponification of polyvinyl alcohol to less than 50%, the solubility in an organic solvent can be easily improved. The impurity diffusion composition (a) containing the polymer of the silane compound represented by the general formula (2) has low solubility in water and a high ratio of the organic solvent in the solvent, so that the solubility in the organic solvent is important. May be. Even in such a case, by setting the degree of saponification of polyvinyl alcohol to 20% or more and less than 50%, a very stable complex is formed in an organic solvent system, the diffusion uniformity of impurities is further improved, and diffusion is performed. Impurity diffusion compositions can be provided that allow further progression. A composition that can further promote the progress of diffusion has the advantage that the treatment conditions for obtaining the same diffusion layer state as a result can be milder.

The average degree of polymerization of polyvinyl alcohol is preferably 150 to 1000 in terms of solubility and complex stability. In the present invention, the average degree of polymerization and the degree of saponification are both values measured according to JIS K 6726 (1994). The degree of saponification is a value measured by the back titration method among the methods described in the JIS.

The impurity diffusion composition (a) used in the present invention preferably contains a solvent. Preferred specific examples are acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl-n-pentyl ketone, methyl-n-hexyl ketone, diethyl ketone, dipropyl. Ketone solvents such as ketones, diisobutyl ketones, trimethylnonanones, cyclohexanones, cyclopentanones, methylcyclohexanones, 2,4-pentandiones, acetonylacetones; diethyl ethers, methyl ethyl ethers, methyl-n-propyl ethers, diisopropyl ethers, Tetrahydrofuran, methyl tetrahydrofuran, dioxane, dimethyl dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n-propyl ether, ethylene glycol dibutyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol Methyl-n-propyl ether, diethylene glycol methyl-n-butyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, diethylene glycol methyl-n-hexyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene Glycolmethylethyl ether, triethylene glycol methyl-n-butyl ether, triethylene glycol di-n-butyl ether, triethylene glycol methyl-n-hexyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol methyl ethyl ether , Tetraethylene glycol methyl-n-butyl ether, tetraethylene glycol di-n-butyl ether, tetraethylene glycol methyl-n-hexyl ether, tetraethylene glycol di-n-butyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di -N-propyl ether, propylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl ether Chill ether, dipropylene glycol methyl-n-butyl ether, dipropylene glycol di-n-propyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol methyl-n-hexyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether , Tripropylene glycol methyl ethyl ether, tripropylene glycol methyl-n-butyl ether, tripropylene glycol di-n-butyl ether, tripropylene glycol methyl-n-hexyl ether, tetrapropylene glycol dimethyl ether, tetrapropylene glycol diethyl ether, tetrapropylene glycol Ether solvents such as methyl ethyl ether, tetrapropylene glycol methyl-n-butyl ether, tetrapropylene glycol di-n-butyl ether, tetrapropylene glycol methyl-n-hexyl ether, tetrapropylene glycol di-n-butyl ether; methyl acetate, ethyl acetate , N-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethyl acetate Ethylhexyl, 2- (2-butoxyethoxy) ethyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, nonyl acetate, methyl acetoacetate, ethyl acetoacetate, diethylene glycol methyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl acetate Ether, dipropylene glycol ethyl acetate ether, glycol diacetate, methoxytriethylene glycol acetate, ethyl propionate, n-butyl propionate, isoamyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate , N-butyl lactate, n-amyl lactate, ethylene glycol methyl ether propionate, ethylene glycol ethyl ether propionate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate , Propylene glycol propyl ether acetate, γ-butyrolactone, γ-valerolactone, etc. Ester solvent; acetonitrile, N-methylpyrrolidinone, N-ethylpyrrolidinone, N-propylpyrrolidinone, N-butylpyrrolidinone, N-hexylpyrrolidinone, N-cyclohexylpyrrolidinone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl Apropylene polar solvents such as sulfoxide; methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec- Pentanol, t-pentanol, 3-methoxybutanol, 3-methoxy-3-methylbutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, n-octanol, 2 -Ethylenehexanol, sec-octanol, n-nonyl alcohol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, benzyl alcohol , Isobornylcyclohexanol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol and other alcohol solvents; ethylene glycol monomethyl ether, ethylene glycol mono Ethylene ether (cellosolve), ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol mono-n-butyl ether, propylene Glycol monoether solvents such as glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether; α-terpinene, α-terpineol, milsen, aloosimene, limonene, dipentene, α-pinene, β -Terpen solvents such as pinen, tarpineol, carboxylic, ossimen, ferrandylene; isobornylcyclohexanol, isovo Examples include runylphenol, 1-isopropyl-4-methyl-bicyclo [2.2.2] octa-5-ene-2,3-dicarboxylic acid anhydride, p-maintenylphenol, and water. These can be used alone or in combination of two or more.

However, when the polymer of the silane compound (a-1) in the impurity diffusion composition (a) has a structure represented by the general formula (2), the proportion of water is set in consideration of the solubility of the polymer of the silane compound. It is preferably 20% by mass or less based on the total solvent.

In particular, a solvent having a boiling point of 100 ° C. or higher is preferable from the viewpoint of further improving printability when a screen printing method, a spin coating printing method, or the like is used. When the boiling point is 100 ° C. or higher, for example, when the impurity diffusion composition is printed on the printing plate used in the screen printing method, it becomes easy to prevent the impurity diffusion composition from drying and sticking on the printing plate.

The content of the solvent having a boiling point of 100 ° C. or higher is preferably 20% by mass or more with respect to the total amount of the solvent. Solvents having a boiling point of 100 ° C. or higher include diethylene glycol methyl ethyl ether (boiling point of 176 ° C.), ethylene glycol monoethyl ether acetate (boiling point of 156.4 ° C.), ethylene glycol monomethyl ether acetate (boiling point of 145 ° C.), and methyl lactate (boiling point of 145 ° C.). ), Ethyl lactate (boiling point 155 ° C), diacetone alcohol (boiling point 169 ° C), propylene glycol monomethyl ether acetate (boiling point 145 ° C), 3-methoxy-3-methyl-1-butanol (boiling point 174 ° C), dipropylene glycol Monomethyl ether (boiling point 188 ° C), dipropylene glycol-n-butyl ether (boiling point 229 ° C), γ-butyrolactone (boiling point 204 ° C), diethylene glycol monoethyl ether acetate (boiling point 217 ° C), butyl diglycol acetate (boiling point 246 ° C) , Ethyl acetoacetate (boiling point 181 ° C), N-methyl-2-pyrrolidone (boiling point 204 ° C), N, N-dimethylimidazolidinone (boiling point 226 ° C), dipropylene glycol methyl ether acetate (boiling point 213 ° C), 1 , 3-butylene glycol diacetate (boiling point 232 ° C.), diisobutylketone (boiling point 168 ° C.), propylene glycol t-butyl ether (boiling point 151 ° C.), propylene glycol n-butyl ether (boiling point 170 ° C.), acetylacetone (boiling point 140 ° C.), Examples thereof include diethylene glycol monobutyl ether (boiling point of 171 ° C.) and diethylene glycol monobutyl ether acetate (boiling point of 245 ° C.).

The impurity diffusion composition (a) used in the present invention may contain a surfactant. By containing a surfactant, uneven coating is improved and a uniform coating film can be obtained. As the surfactant, a fluorine-based surfactant or a silicone-based surfactant is preferably used.

Specific examples of the fluorine-based surfactant include 1,1,2,2-tetrafluorooctyl (1,1,2,2-tetrafluoropropyl) ether and 1,1,2,2-tetrafluorooctyl. Hexyl ether, octaethylene glycol di (1,1,2,2-tetrafluorobutyl) ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoropentyl) ether, octapropylene glycol di (1) , 1,2,2-tetrafluorobutyl) ether, hexapropylene glycol di (1,1,2,2,3,3-hexafluoropentyl) ether, sodium perfluorododecylsulfonate, 1,1,2,2 , 8,8,9,9,10,10-decafluorodecan, 1,1,2,2,3,3-hexafluorodecane, N- [3- (perfluorooctane sulfonamide) propyl] -N, N'-dimethyl-N-carboxymethyleneammonium betaine, perfluoroalkylsulfonamide propyltrimethylammonium salt, perfluoroalkyl-N-ethylsulfonylglycine salt, bis phosphate (N-perfluorooctylsulfonyl-N-ethylaminoethyl) , Monoperfluoroalkylethyl phosphate, etc. Fluorescent surfactants comprising compounds having a fluoroalkyl or fluoroalkylene group at at least any of the terminal, main chain and side chains can be mentioned. In addition, as commercially available products, Megafuck F142D, F172, F173, F183, F444, F475, F477 (all manufactured by Dainippon Ink and Chemicals Co., Ltd.), Ftop EF301, 303, same 352 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC-430, same FC-431 (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, same SC-103, SC-104, SC-105, SC-106 (manufactured by Asahi Glass Co., Ltd.), BM-1000, BM-1100 (manufactured by Yusho Co., Ltd.), NBX-15, FTX-218, There are fluorine-based surfactants such as DFX-218 (manufactured by Neos Co., Ltd.).

Commercially available silicone-based surfactants include SH28PA, SH7PA, SH21PA, SH30PA, ST94PA (all manufactured by Toray Dow Corning Co., Ltd.), BYK067A, BYK310, BYK322, BYK331, BYK333, BYK355 (Big Chemie Japan Co., Ltd.). ) Made) and so on.

When the surfactant is contained, the content is preferably 0.0001 to 1% by mass in the impurity diffusion composition.

The impurity diffusion composition (a) used in the present invention preferably contains a thickener for adjusting the viscosity. As a result, it is possible to apply a more precise pattern by a printing method such as screen printing.

As the thickener, in the organic system, cellulose, cellulose derivative, starch, starch derivative, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyurethane resin, polyurea resin, polyimide resin, polyamide resin, epoxy resin, polystyrene type Resin, polyester resin, synthetic rubber, natural rubber, polyacrylic acid, various acrylic resins, polyethylene glycol, polyethylene oxide, polypropylene glycol, polypropylene oxide, silicone oil, sodium alginate, xanthan gum polysaccharide, gellan gum polysaccharide, guar gum Polysaccharides, carrageenan-based polysaccharides, locust bean gum-based polysaccharides, carboxyvinyl polymers, hydrogenated castor oil-based, hydrogenated castor oil-based and fatty acid amide wax-based, special fatty acid-based, polyethylene oxide-based, polyethylene oxide-based and amide-based mixture , Fatty acid-based polyvalent carboxylic acid, phosphoric acid ester-based surfactant, long-chain polyaminoamide and phosphate salt, specially modified polyamide-based, and the like. In the inorganic system, bentonite, montmorillonite, magnesian montmorillonite, tetsumonmorironite, tetsumagnesian montmorillonite, bidelite, aluminan bidelite, support stone, aluminian support stone, laponite, aluminum silicate, aluminum silicate Examples thereof include magnesium, organic hectorite, fine-grained silicon oxide, colloidal alumina, and calcium carbonate. These may be used in combination of a plurality of types.

Commercially available cellulosic thickeners include 1110, 1120, 1130, 1140, 1150, 1160, 1170, 1180, 1190, 2200, 2260, 2280, and 2450 (all manufactured by Daicel Finechem Co., Ltd.). Can be mentioned.

Commercially available polysaccharide thickeners include ViscalinPC209, ViscalinPC389, SeaKemXP8012 (all manufactured by FMC Chemicals Co., Ltd.), CAM-H, GJ-182, SV-300, LS-20, LS-30, Examples thereof include XGT, XGK-D, G-100, and LG-10 (all of which are Mitsubishi Corporation).

Commercially available acrylic thickeners include # 2434T, KC7000, KC1700P (above, manufactured by Kyoeisha Chemical Co., Ltd.), AC-10LHPK, AC-10SHP, 845H, PW-120 (above, manufactured by Toagosei Co., Ltd.). ) And so on.

Examples of commercially available hydrogenated castor oil-based thickeners include Disparon 308, NAMLONT-206 (above, manufactured by Kusumoto Kasei Co., Ltd.), T-20SF, T-75F (above, manufactured by Itoh Oil Chemicals Co., Ltd.), etc. Be done.

Commercially available polyethylene oxide-based thickeners include D-10A, D-120, D-120-10, D-1100, DS-525, DS-313 (all manufactured by Itoh Oil Chemicals Co., Ltd.), and Disparon 4200. -20, PF-911, PF-930, 4401-25X, NS-30, NS-5010, NS-5025, NS-5810, NS-5210, NS-5310 (and above, Examples thereof include Kusumoto Kasei Co., Ltd., Fronon SA-300, and SA-300H (all manufactured by Kyoeisha Chemical Co., Ltd.).

Commercially available amide thickeners include T-250F, T-550F, T-850F, T-1700, T-1800, T-2000 (all manufactured by Itoh Oil Chemicals Co., Ltd.), Disparon 6500, 6300. , 6650, 6700, 3900EF (manufactured by Kusumoto Kasei Co., Ltd.), Tarren 7200, 7500, 8200, 8300, 8700, 8900, KY-2000, KU-700, M- 1020, VA-780, VA-750B, 2450, Flownon SD-700, SDR-80, EC-121 (all manufactured by Kyoeisha Chemical Co., Ltd.) and the like.

Commercially available bentonite thickeners include Wenger, Wenger HV, HVP, F, FW, Bright 11, A, W-100, W-100U, W-300U, SH, etc. Examples thereof include Multiben, Esben, Esben C, E, W, P, WX, Organite, and Organite D (all manufactured by Hojun Co., Ltd.).

Commercially available fine particle silicon oxide thickeners include AEROSILR972, R974, NY50, RY200S, RY200, RX50, NAX50, RX200, RX300, VPNKC130, R805, R104, and R711. , OX50, 50, 90G, 130, 200, 300, 380 (all manufactured by Nippon Aerosil Co., Ltd.), WACKER HDK S13, V15, N20, N20P, T30, T40 , H15, H18, H20, H30 (all manufactured by Asahi Kasei Corporation) and the like.

The thickener preferably has a 90% thermal decomposition temperature of 400 ° C. or lower from the viewpoint of forming a dense film and reducing residues. Specifically, polyethylene glycol, polyethylene oxide, polypropylene glycol, polypropylene oxide, and various acrylic acid ester-based resins are preferable, and polyethylene oxide, polypropylene oxide, and acrylic acid ester-based resin are particularly preferable. From the viewpoint of storage stability, acrylic ester-based resins are particularly preferable. Here, the 90% thermal decomposition temperature is a temperature at which the weight of the thickener is reduced by 90% due to thermal decomposition. The 90% pyrolysis temperature can be measured using a thermogravimetric analyzer (TGA) or the like.

Examples of acrylate-based resins include polymethyl methacrylate, ethyl polymethacrylate, propyl polymethacrylate, butyl polymethacrylate, methyl polyacrylate, ethyl polyacrylate, propyl polyacrylate, butyl polyacrylate, and polyhydroxyethyl. Examples thereof include polyacrylic acid esters such as methacrylate, polybenzyl methacrylate, and polyglycidyl methacrylate, and copolymers thereof. In the case of a copolymer, the above acrylic acid ester component may have a polymerization ratio of 60 mol% or more, and a vinyl polymerizable component such as polyacrylic acid or polystyrene may be copolymerized as another copolymerization component. ..

Further, for polyethylene oxide and polypropylene oxide, these two types of copolymers are also preferable. Acrylic ester-based resins, polyethylene oxides, and polypropylene oxides all having a weight average molecular weight of 100,000 or more have a high thickening effect and are preferable.

The content of these thickeners is preferably 3% by mass or more and 20% by mass or less in the impurity diffusion composition. Within this range, a sufficient viscosity adjusting effect can be obtained, and at the same time, it becomes easy to form a dense film.

From the viewpoint of screen printability, the impurity diffusion composition (a) in the present invention preferably contains a tix agent that imparts tix property. Here, imparting the thixo property means increasing the ratio (η1 / η2) of the viscosity (η1) at the time of low shear stress and the viscosity (η2) at the time of high shear stress. The pattern accuracy of screen printing can be improved by containing a thixogen. It is presumed that it is due to the following reasons. That is, since the impurity diffusion composition containing a thixogen has a low viscosity at high shear stress, clogging of the screen is unlikely to occur during screen printing, and the viscosity is high at low shear stress, so that bleeding and pattern line width immediately after printing are present. It is presumed that the fatness of the body is less likely to occur.

Specific examples of the thixo agent include cellulose, cellulose derivatives, sodium alginate, xanthan gum polysaccharides, gellan gum polysaccharides, guar gum polysaccharides, carrageenan polysaccharides, locust bean gum polysaccharides, carboxyvinyl polymers, and hydrogenators. With castor oil, hydrogenated castor oil and fatty acid amide wax, special fatty acid, polyethylene oxide, mixture of polyethylene oxide and amide, fatty acid polysaccharide, phosphate ester surfactant, long chain polyaminoamide Carboxylic acid salt, specially modified polysaccharides, bentonite, montmorillonite, magnesian montmorillonite, tetsumonmorironite, tetsumagnesian montmorillonite, byderite, alumin byderite, support stone, aluminian support stone, laponite, kay Examples thereof include aluminum acid, aluminum magnesium silicate, organic hectrite, fine particle silicon oxide, colloidal alumina, and calcium carbonate. The thix agent can be used alone, but it is also possible to combine two or more kinds of thix agents. Further, it is more preferable to use it in combination with the thickener, and a higher effect can be obtained.

The viscosity of the impurity diffusion composition in the present invention is not limited and can be appropriately changed depending on the printing method and the film thickness. Here, for example, in the case of the screen printing method, which is one of the preferable printing forms, the viscosity of the impurity diffusion composition is preferably 5,000 mPa · s or more. This is because bleeding of the print pattern can be suppressed and a good pattern can be obtained. A more preferable viscosity is 10,000 mPa · s or more. There is no particular upper limit, but 100,000 mPa · s or less is preferable from the viewpoint of storage stability and handleability. Here, when the viscosity is less than 1,000 mPa · s, it is a value measured at a rotation speed of 20 rpm using an E-type digital viscometer based on JIS Z 8803 (1991) “Solution Viscosity-Measurement Method”. In the case of 1,000 mPa · s or more, it is a value measured at a rotation speed of 20 rpm using a B-type digital viscometer based on JIS Z 8803 (1991) “Solution Viscosity-Measuring Method”. The tixo property can be determined from the ratio of viscosities at different rotation speeds obtained by the above viscosity measuring method. In the present invention, the ratio (η2 / η20) of the viscosity (η20) at a rotation speed of 20 rpm to the viscosity (η2) at a rotation speed of 2 rpm is defined as the thixo property. In order to form a pattern with high accuracy in screen printing, the thixo property is preferably 2 or more, and more preferably 3 or more.

In the present invention, the solid content concentration of the impurity diffusion composition (a) is not particularly limited, but is preferably 1% by mass or more and 90% by mass or less. If it is lower than this concentration range, the coating film thickness may become too thin and it may be difficult to obtain the desired doping property and masking property, and if it is higher than this concentration range, the storage stability may decrease.
<Impurity diffusion composition (d)>
In the present invention, the first preferred embodiment of the impurity diffusion composition (d) contains an impurity diffusion composition (d) containing a polymer of a (d-1) silane compound and (d-2) an impurity diffusion component. That is.

The silane compound polymer (d-1) includes a polycondensate of a monomer containing a Si atom, an addition polymer, a polyadduct, and the like.

In the first preferred embodiment of the impurity diffusion composition (d), the silane compound polymer (d-1) is preferably a polymer of the silane compound represented by the following general formula (3).

In the general formula (3), R ⁷ and R ⁸ are hydroxyl groups, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, and acyloxy groups having 2 to 6 carbon atoms. , Represents any of the aryl groups having 6 to 15 carbon atoms, and the plurality of R ⁷ and R ⁸ may be the same or different, respectively. l ₂ represents an integer of 1 to 10000. From the viewpoint of the toughness of the film after film formation, it is preferably 5 to 10000, more preferably 10 to 10000.

Alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkenyl group having 2 to 10 carbon atoms, acyloxy group having 2 to 6 carbon atoms, and carbon number of carbon atoms in ^{R 7} and R ⁸ of the general formula (3). The aryl groups 6 to 15 may be either unsubstituted or substituted, and can be selected according to the characteristics of the impurity diffusion composition.

Specific examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, the alkenyl group having 2 to 10 carbon atoms, the acyloxy group having 2 to 6 carbon atoms, and the aryl group having 6 to 15 carbon atoms include The same as those in R ¹ and R ^{2 can be mentioned.}

From the viewpoint of facilitating suppression of outdiffusion from the impurity diffusion composition ^{, at least one of R 7} and R ⁸ is an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and 2 to 6 carbon atoms. It is preferable that it represents any of an acyloxy group and an aryl group having 6 to 15 carbon atoms.

More preferably, R ⁷ represents any one of an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, and an aryl group having 6 to 15 carbon atoms. R ⁸ represents any of a hydroxyl group and an alkoxy group having 1 to 6 carbon atoms.

In the first preferred embodiment of the impurity diffusion composition (d), from the viewpoint of facilitating suppression of outdiffusion from the impurity diffusion composition, the polymer of the (d-1) silane compound is prepared by the following general formula (4). ) Is more preferable.

In the general formula (4), R ⁹ is an aryl group having 6 to 15 carbon atoms, may be with or different plurality of R ⁹ is the same, respectively. R ¹⁰ is a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, and an aryl group having 6 to 15 carbon atoms. Representing either, the plurality of R ^10s may be the same or different. R ¹¹ and R ¹² represent any one of a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and an acyloxy group having 2 to 6 carbon atoms. R ⁵ and R ^{6 of the above} may be the same or different, respectively. n ₂ and m ₂ represent an integer of 1 to 9999, n ₂ + m ₂ is an integer of 2 to 10000, and n ₂ : m ₂ = 95: 5 to 25:75.
From the viewpoint of the toughness of the film after film _{formation, the range of (n 2} + m ₂ ) is preferably 5 to 10000, and more preferably 10 to 10000.

^{The aryl group having 6 to 15 carbon atoms in R 9} of the general formula (4) may be an unsubstituted or substituted product, and can be selected according to the characteristics of the impurity diffusion composition. Specific examples of the aryl group having 6 to 15 carbon atoms include those similar to those in ^{R 1} and R ^2.

Alkyl group having 1 to 6 carbon atoms in ^{R 10} of the general formula (4), an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, 6 to 15 carbon atoms The aryl group of can be either an unsubstituted or substituted product, and can be selected according to the characteristics of the impurity diffusion composition. Specific examples of these include those similar to those in ^{R 1} and R ^2.

The alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, the alkenyl group having 2 to 10 carbon atoms, and the acyloxy group having 2 to 6 carbon atoms in ^{R 11} and R ¹² of the general formula (4) are all. Either a non-substituted product or a substituted product may be used, and can be selected depending on the characteristics of the impurity diffusion composition. Specific examples of these include those similar to those in ^{R 1} and R ^2.

Specific examples of the organosilane which is the raw material of the polymer of the silane compound represented by the general formula (3) are the same as the specific examples of the organosilane which is the raw material of the polymer of the silane compound represented by the general formula (1). Things can be mentioned.

Among these organosilanes, trifunctional silanes are preferably used from the viewpoint of facilitating suppression of outdiffusion from the impurity diffusion composition.

Specific examples of the organosilane that can be used as a raw material for the unit having ^{R 9} and R ¹⁰ of the silane compound represented by the general formula (4) ^{include R 3} and R ^{4 of the silane compound represented by the general formula (2).} Specific examples of the organosilane that can be used as a raw material for the unit having the above can be mentioned.

^{Specific examples of the organosilane that can be used as a raw material for the unit having R 11} and R ¹² of the general formula (4) include the organosilane that is the raw material of the polymer of the silane compound represented by the general formula (1). The same as the example can be mentioned. Among them, trifunctional silane is preferably used from the viewpoint of facilitating the suppression of outdiffusion from the impurity diffusion composition.

The polymer of the silane compound represented by the general formula (4) is a polysiloxane in which the unit containing an aryl group having 6 to 15 carbon atoms is 25 to 95 mol% in terms of Si atom. That is, n ₂ : m ₂ = 95: 5 to 25:75. Within this range, the effects of suppressing outdiffusion of the impurity diffusion component and reducing the organic residue when the impurity diffusion component is removed after the heat treatment are improved. Further, within this range, even in the impurity diffusion composition to which a thermal decomposition component such as a thickener is added, it becomes possible to fill the vacancies generated by the thermal decomposition due to the reflow effect of siloxane, and the vacancies can be filled. It is possible to form a dense film with less heat. Therefore, it is not easily affected by the atmosphere at the time of diffusion, and a high masking property against other impurities can be obtained.

The terminal group shall be any of hydrogen, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, and an alkenyl group having 2 to 10 carbon atoms. Is preferable.

The polymer of the silane compound represented by the general formula (2) may contain each of the constituent components in the above-mentioned predetermined ratio, and may be a block copolymer or a random copolymer.
From the viewpoint of suppressing out-diffusion and further improving the masking property, the unit containing an aryl group having 6 to 15 carbon atoms is more preferably 35 mol% or more, further preferably 40 mol% or more. Further, in order not to generate a residue without being affected by the atmosphere and the film thickness, the amount of the aryl group-containing unit is preferably 80 mol% or less. That is, it is particularly preferable that _{n 2} : m _{2 = 80:20 to 40:60.}

The polymer of the silane compound represented by the general formulas (3) and (4) is obtained by, for example, hydrolyzing the organosilane compound and then subjecting the hydrolyzate to a condensation reaction in the presence of a solvent or in the absence of a solvent. Obtainable. The specific method is the same as that of the polymer of the silane compound represented by the general formulas (1) and (2).

Specific examples of the impurity diffusion component (d-2) contained in the first preferred embodiment of the impurity diffusion composition (d) are the same as those of the impurity diffusion component contained in the impurity diffusion composition (a).

Further, when the polymer of the (d-1) silane compound in the impurity diffusion composition (d) has a structure represented by the general formula (4), the degree of saponification (d-3) is 20 mol% or more and 50 mol. May contain less than% polyvinyl alcohol. A specific example of (d-3) is the same as that of (a-3).

The first preferred embodiment of the impurity diffusion composition (d) may include a solvent, a surfactant, a thickener, and a thixo agent. Specific examples are the same as those of the solvent, the surfactant, the thickener, and the thixant contained in the impurity diffusion composition (a).

In the present invention, the second preferred embodiment of the impurity diffusion composition (d) is that the impurity diffusion composition (d) is at least one selected from the group consisting of (d-4) polyvinyl alcohol and polyether oxide. The seed resin, (d-5) impurity diffusing component, and (d-6) water are contained in an amount of 25% by mass or more in the total solvent.

In the second preferred embodiment of the impurity diffusion composition (d), at least one resin selected from the group consisting of (d-4) polyvinyl alcohol and polyethylene oxide complex with the (d-5) impurity diffusion component. It is a component for forming and forming a uniform film at the time of application. From the viewpoint of (d-5) formability of the complex with the impurity diffusion component and stability of the formed complex, at least one resin selected from the group consisting of (d-4) polyvinyl alcohol and polyethylene oxide is polyvinyl. Alcohol is more preferred.

The average degree of polymerization of polyvinyl alcohol is preferably 150 to 1000 in terms of solubility and complex stability. Further, the saponification degree of polyvinyl alcohol is preferably 70 to 95 mol% in terms of solubility in water and complex stability. In the present invention, the average degree of polymerization and the degree of saponification are both values measured according to JIS K 6726 (1994), and the degree of saponification is a value measured by the back titration method.

In terms of complex stability, the resin (d-4) contained in the impurity diffusion composition is 80% by mass or more, preferably 90% by mass or more, most preferably 90% by mass or more of all the resins contained in the impurity diffusion composition. It is preferably 95% by mass or more.

Further, in terms of heat diffusion and suppression of organic residues on the substrate after removal of the impurity diffusion composition, the amount of the resin (d-4) is preferably 0.1 to 20% by mass of the entire impurity diffusion composition. More preferably, it is 1 to 10% by mass.

In the second preferred embodiment of the impurity diffusion composition (d), the specific example of the impurity diffusion component (d-5) is the same as that of the impurity diffusion component contained in the impurity diffusion composition (a).

Further, specific examples of the solvent, the surfactant, the thickener, and the thix agent are the same as those of the solvent, the surfactant, the thickener, and the thix agent contained in the impurity diffusion composition (a).

<Manufacturing method of semiconductor element (selective emitter)>
The method for manufacturing a semiconductor device of the present invention is a method for manufacturing a semiconductor device in which the same type of impurity diffusion layer region is formed on a semiconductor substrate at two or more levels of different impurity concentrations, of which at least one level or more of impurity diffusion. The layer region is a step of applying the impurity diffusion composition (a) to the semiconductor substrate to partially form the impurity diffusion composition film (b) and heating it to diffuse the impurities to the semiconductor substrate to diffuse the impurity diffusion layer. It is formed by a method including a step of forming a region (c), and the impurity diffusion composition (a) is (a-1) a semiconductor of a silane compound represented by the general formula (1), and (a-2) an impurity. Contains diffusing components. The different impurity concentrations referred to here are 1 × 10 ¹⁷ / cm ³ or more in terms of impurity concentration difference, and the difference in sheet resistance value on the substrate surface of the portion where the impurity diffusion layer region is formed is 10 Ω / □ or more. Point to.

The first preferred embodiment of the method for producing a semiconductor device of the present invention preferably includes a step of diffusing impurities into an impurity diffusion composition film (b) unformed portion using the impurity diffusion composition film (b) as a mask. ..

Hereinafter, the first preferred embodiment of the method for manufacturing a semiconductor device of the present invention will be described with reference to the drawings. All of these are examples, and the method for manufacturing a semiconductor device of the present invention is not limited to these.

First, as shown in FIG. 1 (i), the impurity diffusion composition (a) is partially coated on the semiconductor substrate 1 to form the pattern 4 of the impurity diffusion composition film (b).

Examples of the semiconductor substrate include ^{n-type single crystal silicon and polycrystalline silicon having an impurity concentration of 10 15} to ¹⁶ atoms / cm ³ , and a crystalline silicon substrate in which other elements such as germanium and carbon are mixed. Can be mentioned. It is also possible to use p-type crystalline silicon or a semiconductor other than silicon. The semiconductor substrate is preferably a substantially quadrangle having a thickness of 50 to 300 μm and an outer shape of 100 to 250 mm on a side. Further, in order to remove slice damage and a natural oxide film, it is preferable to etch the surface with a hydrofluoric acid solution or an alkaline solution.

Examples of the coating method of the impurity diffusion composition (a) include a spin coating method, a screen printing method, an inkjet printing method, a slit coating method, a spray coating method, a letterpress printing method, and an intaglio printing method.

After applying the impurity diffusion composition (a) by these methods, the semiconductor substrate coated with the impurity diffusion composition (a) is dried on a hot plate, an oven, or the like in a range of 50 to 260 ° C. for 30 seconds to 30 minutes. , It is preferable to form the pattern of the impurity diffusion composition film (b).

A more preferable drying temperature is 180 to 260 ° C. from the viewpoint of advancing the curing of the polymer of the silane compound and improving the in-plane uniformity of the impurity concentration after diffusion by suppressing volatilization such as sublimation of impurities. The temperature. From the same viewpoint, the oxygen concentration at the time of drying is preferably 15 to 25%.

The film thickness of the impurity diffusion composition film (b) after drying is preferably 100 nm or more from the viewpoint of impurity diffusibility, and preferably 3 μm or less from the viewpoint of the residue after etching.

Next, as shown in FIG. 1 (ii), the impurities are heated and diffused on the semiconductor substrate to form the impurity diffusion layer region (c). As a method for diffusing impurities, a known heat diffusing method can be used, and for example, a method such as electric heating, infrared heating, laser heating, or microwave heating can be used.

The time and temperature of thermal diffusion can be appropriately set so as to obtain desired diffusion characteristics such as impurity diffusion concentration and diffusion depth. For example, a diffusion layer having ^{a surface impurity concentration of 10 19} to ²¹ can be formed by heating and diffusing at 800 ° C. or higher and 1200 ° C. or lower for 1 to 120 minutes.

However, the higher the diffusion temperature, the higher the defect density of the silicon substrate, the shorter the lifetime, and the lower the light conversion efficiency of the solar cell. It is preferable to allow the diffusion to proceed under mild conditions.

The diffusion atmosphere is not particularly limited, and may be carried out in the atmosphere, or the amount of oxygen in the atmosphere may be appropriately controlled by using an inert gas such as nitrogen or argon. From the viewpoint of shortening the diffusion time, it is preferable to reduce the oxygen concentration in the atmosphere to 3% or less. Further, if necessary, the organic substances in the impurity diffusion composition film (b) may be decomposed and removed by firing in the range of 200 ° C. to 850 ° C. before diffusion.

Next, as described above, it is preferable to include a step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) using the impurity diffusion composition film (b) as a mask. Specifically, for example, as shown in FIGS. 1 (iv-1) to 1 (iv-3), the pattern of the impurity diffusion composition film (b) is used as a mask to cover the impurity diffusion layer region (in the pattern-unformed portion). An impurity diffusion layer region (f) having the same type of conductivity as c) and having a different impurity concentration is formed.

In the first preferred embodiment of the method for producing a semiconductor element of the present invention, the step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) (step of forming the impurity diffusion layer region (f)) is an impurity. This can be performed after the diffusion composition film (b) is heated to diffuse impurities on the semiconductor substrate to form an impurity diffusion layer region (c).

As a specific example of the method of diffusing impurities in the non-formed portion of the impurity diffusion composition film (b), after injecting ions containing an impurity diffusion component into the patterned semiconductor substrate 1 of the impurity diffusion composition film (b) (FIG. 1). (Iii-1)) Annealing (iv-1) method, impurity diffusion composition The patterned semiconductor substrate 1 of the film (b) is heated in an atmosphere containing an impurity diffusion component (iv-2), impurity diffusion composition. After the impurity diffusion composition (d) is applied to the non-formed portion of the impurity diffusion composition film (b) on the patterned semiconductor substrate 1 of the material film (b) to form the impurity diffusion composition film (e) (FIG. 1 (iii-3)), electric heating, infrared heating, laser heating, microwave heating (iv-3), and the like can be mentioned.

In the first preferred embodiment of the method for producing a semiconductor composition of the present invention, the step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) is a step of injecting ions containing an impurity diffusion component. This is the first more preferred embodiment.

In the step of implanting ions, implantation of boron, for example, at an energy of 1～40KeV, dose between ^0.5~5e 15 1 / cm ^2, preferably, the energy of 3～10KeV, 1.5 ~ 3e ¹⁵ 1 / cm ² Doze amount. The resistance of the boron-injected impurity diffusion layer region (f) is 30 to 300 ohm squares (ohm / square, Ω / □), preferably 60 to 100 ohm squares after recovery.

Implantation of phosphorus, for example, at an energy of 1～40KeV, dose between ^0.5~5e 15 1 / cm ^2, preferably at an energy of 10 keV, between the ^2.5~4e 15 1 / cm ² Do with the amount of dose. The resistance of the phosphorus-injected impurity diffusion layer region (f) is 10 to 300 ohm squares (ohm / square, Ω / □), preferably 30 to 120 ohm squares after recovery.

Recovery (activation of implanted dopants) has a patterned semiconductor substrate impurity diffusion composition layer (b) in an inert atmosphere _(N 2, Ar), carried out by annealing at high temperatures (800-1100 ° C.) be able to.

Depending on the ion implantation energy, dose amount, and temperature condition setting during recovery, the impurity concentration in the impurity diffusion layer region (f) may be set higher or lower than the impurity concentration in the impurity diffusion layer region (c). It will be possible.

In the first preferred embodiment of the method for manufacturing a semiconductor element of the present invention, the step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) (step of forming the impurity diffusion layer region (f)) is an impurity. The diffusion composition film (b) may be heated at the same time as the step of diffusing impurities into the semiconductor substrate.

For example, as shown in FIG. 1 (i), the impurity diffusion composition (a) is partially coated on the semiconductor substrate 1 to form the pattern of the impurity diffusion composition film (b), and then FIG. 1 ( Without performing the diffusion step of ii), the ion implantation of FIG. 1 (iii-1) was performed, and the impurity diffusion layer region (f) and the impurity diffusion layer region (c) were simultaneously subjected to the annealing of FIG. 1 (iv-1). It may be formed. Further, as described later, the impurity diffusion layer region (f) and the impurity diffusion layer region (c) can be formed at the same time in the second more preferable embodiment and the third more preferred embodiment.

In the first preferred embodiment of the method for manufacturing a semiconductor device of the present invention, the step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) is a step of heating in an atmosphere containing an impurity diffusing component. Is the second more preferred embodiment.

When heating in an atmosphere containing an impurity diffusion component, for example in the case of p-type boron tribromide (BBr 3), in the case of _n-type by bubbling phosphorus oxychloride (POCl _3), by flowing in N ₂ The patterned semiconductor substrate of the impurity diffusion composition film (b) can be heated in an atmosphere containing an impurity diffusion component to form the impurity diffusion layer region (f). By setting the gas pressure and heating conditions, the impurity concentration in the impurity diffusion layer region (f) can be set higher or lower than the impurity concentration in the impurity diffusion layer region (c).

At this time, in order to avoid mixing of other components, the impurity diffusion layer region (c) is formed by the diffusion step of FIG. 1 (ii) after the pattern of the impurity diffusion composition film (b) is formed, and FIG. 1 (iv). It is preferable that the impurity diffusion layer region (f) is continuously formed by the heating of -2) in the same batch of diffusion devices.

Further, as shown in FIG. 1 (i), the impurity diffusion composition (a) is partially coated on the semiconductor substrate 1 to form the pattern of the impurity diffusion composition film (b), and then FIG. 1 ( The impurity diffusion layer region (f) and the impurity diffusion layer region (c) may be formed at the same time by heating in FIG. 1 (iv-2) without performing the diffusion step of ii).

Further, as shown in FIG. 1 (i), the impurity diffusion composition (a) is partially coated on the semiconductor substrate 1 to form the pattern of the impurity diffusion composition film (b), and then FIG. 1 ( Without performing the diffusion step of ii), it is put into the heating furnace of FIG. 1 (iv-2), first heated only with an inert gas to form an impurity diffusion layer region (c), and then the impurities are diffused into the furnace as it is. By additionally introducing a gas containing a component and heating under conditions different from the heating conditions of only the inert gas, the impurity diffusion layer region (f) having an impurity concentration different from that of the impurity diffusion layer region (c) can be formed in one batch. It may be formed.

In the first preferred embodiment of the method for manufacturing a semiconductor element of the present invention, the step of diffusing impurities into the portion where the impurity diffusion composition film (b) is not formed is a semiconductor substrate on which the impurity diffusion composition film (b) is formed. The third more preferable step is to heat the impurity diffusion composition film (e) formed by applying the impurity diffusion composition (d) to the non-formed portion of the impurity diffusion composition film (b). It is an aspect.

Examples of the coating method of the impurity diffusion composition (d) include a spin coating method, a screen printing method, an inkjet printing method, a slit coating method, a spray coating method, a letterpress printing method, and an intaglio printing method.

Examples of the step of heating the impurity diffusion composition film (e) include electric heating, infrared heating, laser heating, and microwave heating.

In particular, by applying so as to cover the pattern of the impurity diffusion composition film (b), impurity diffusion can be performed well even at the interface between the impurity diffusion composition film (b) and the impurity diffusion composition film (e). Therefore, it can be said that it is preferable. The most preferable for good impurity diffusion at the interface is to apply the impurity diffusion composition (d) to the entire surface of the substrate so as to cover the pattern of the impurity diffusion composition film (b).

After applying the impurity diffusion composition (d) by these methods, the semiconductor substrate 1 coated with the impurity diffusion composition (d) is dried on a hot plate, an oven, or the like in a range of 50 to 200 ° C. for 30 seconds to 30 minutes. It is preferable to form the impurity diffusion composition film (e).

Next, as shown in FIG. 1 (iv-3), impurities are diffused into the semiconductor substrate 1 to form an impurity diffusion layer region (f). As a method for diffusing impurities, a known heat diffusing method can be used, and for example, a method such as electric heating, infrared heating, laser heating, or microwave heating can be used.

The time and temperature of thermal diffusion can be appropriately set so as to obtain desired diffusion characteristics such as impurity diffusion concentration and diffusion depth. For example, a diffusion layer having ^{a surface impurity concentration of 10 19} to ²¹ can be formed by heating and diffusing at 800 ° C. or higher and 1200 ° C. or lower for 1 to 120 minutes.

However, the higher the diffusion temperature, the higher the defect density of the silicon substrate, the shorter the lifetime, and the lower the light conversion efficiency of the solar cell. It is preferable to allow the diffusion to proceed under mild conditions.

The diffusion atmosphere is not particularly limited, and may be carried out in the atmosphere, or the amount of oxygen in the atmosphere may be appropriately controlled by using an inert gas such as nitrogen or argon. From the viewpoint of shortening the diffusion time, it is preferable to reduce the oxygen concentration in the atmosphere to 3% or less. Further, if necessary, the organic substances in the impurity diffusion composition film (e) may be decomposed and removed by firing in the range of 200 ° C. to 850 ° C. before diffusion.

At this time, by adjusting the impurity concentration of the impurity diffusion composition (d) and the film thickness of the impurity diffusion composition film (e), the impurity concentration of the impurity diffusion layer region (f) can be adjusted to the impurity diffusion layer region (c). It is possible to set it higher or lower than the impurity concentration of.

Further, as shown in FIG. 1 (i), the impurity diffusion composition (a) is partially coated on the semiconductor substrate 1 to form the pattern of the impurity diffusion composition film (b), and then FIG. 1 ( The impurity diffusion composition film (e) of FIG. 1 (iii-3) was formed without performing the diffusion step of ii), and the impurity diffusion layer region (f) and impurities were heated by heating of FIG. 1 (iv-3). The diffusion layer region (c) may be formed at the same time.

Among the first to third more preferred embodiments of the first preferred embodiment of the method for manufacturing a semiconductor device of the present invention, points for improving the uniformity of impurity diffusion concentration in the impurity diffusion layer regions (c) and (f). The third, more preferred embodiment is even more preferred.

Next, as shown in FIG. 1 (v), the impurity diffusion composition films (b) and (e) formed on the surface of the semiconductor substrate 1 can be removed by a known etching method. The material used for etching is not particularly limited, but for example, a material containing at least one of hydrogen fluoride, ammonium, phosphoric acid, sulfuric acid, and nitric acid as an etching component and water, an organic solvent, or the like as other components. preferable. By the above steps, it is possible to form two levels of impurity diffusion layers of the same type but different impurity diffusion concentrations on the semiconductor substrate.

A second preferred embodiment of the method for producing a semiconductor element of the present invention is a step of injecting ions containing an impurity diffusion component onto a semiconductor substrate, a step of heating in an atmosphere containing an impurity diffusion component, and an impurity diffusion composition. After forming the impurity diffusion layer region (f) using at least one step selected from the step of heating the impurity diffusion composition film (e) formed by applying (d) over the entire surface, the impurity diffusion composition It includes a step of applying (a) to partially form an impurity diffusion composition film (b) and a step of heating it to diffuse impurities on a semiconductor substrate to form an impurity diffusion layer region (c).

Hereinafter, a second preferred embodiment of the method for manufacturing a semiconductor device of the present invention will be described with reference to the drawings. All of these are examples, and the method for manufacturing a semiconductor device of the present invention is not limited to these.

First, as shown in FIGS. 2 (ii-1) to 2 (ii-3), an impurity diffusion layer region (f) is formed on the semiconductor substrate 1.

Specific examples of the method for forming the impurity diffusion layer region (f) include a method of annealing (ii-1) after injecting ions containing an impurity diffusion component into the semiconductor substrate 1 (FIG. 1 (i-1)) and a semiconductor substrate. The method of heating 1 in an atmosphere containing an impurity diffusion component (ii-2), after applying the impurity diffusion composition (d) to the entire surface of the semiconductor substrate 1 to form an impurity diffusion composition film (e) (Fig. 2 (i-3)), electric heating, infrared heating, laser heating, microwave heating (ii-3), and the like can be mentioned.

The details of each can be carried out in the same manner as described above.

Next, as shown in FIG. 2 (iii), the impurity diffusion composition (a) is partially coated on the semiconductor substrate 1 to form a pattern of the impurity diffusion composition film (b).

The details of pattern formation can be carried out in the same manner as the method described above.

Next, as shown in FIG. 2 (iv), impurities are diffused on the semiconductor substrate 1 to form an impurity diffusion layer region (c).

The details of impurity diffusion can be carried out in the same manner as the method described above.

In the third preferred embodiment of the method for manufacturing a semiconductor element of the present invention, the impurity diffusion composition (d) is entirely coated on a semiconductor substrate to form an impurity diffusion composition film (e), and the impurity diffusion is formed on the impurity diffusion composition film (e). The step of applying the composition (a) to partially form the impurity diffusion composition film (b) and heating them at the same time to diffuse the impurities to the semiconductor substrate to diffuse the impurity diffusion layer regions (c) and (f). ) At the same time.

Hereinafter, a third preferred embodiment of the method for manufacturing a semiconductor device of the present invention will be described with reference to the drawings. All of these are examples, and the method for manufacturing a semiconductor device of the present invention is not limited to these.

For example, as shown in FIG. 2 (i-3), the impurity diffusion composition (d) is entirely coated on the semiconductor substrate 1 to form the impurity diffusion composition film (e), and then FIG. 2 (ii). The pattern of the impurity diffusion composition film (b) of FIG. 2 (iii) was formed without performing the diffusion step of -3), and the impurity diffusion layer region (f) and the impurity diffusion layer were heated by the heating of FIG. 2 (iv). The region (c) can be formed at the same time.

In the second preferred embodiment and the third preferred embodiment of the method for manufacturing a semiconductor device of the present invention, for example, finally, as shown in FIG. 2 (v), the semiconductor substrate 1 is subjected to a known etching method. Impurity diffusion composition films (b) and (e) formed on the surface of the above can be removed. The details can be carried out in the same manner as described above.

The method for manufacturing a semiconductor element of the present invention also applies to a photovoltaic element such as a solar cell and a semiconductor device that forms an impurity diffusion region on the semiconductor surface, for example, a transistor array, a diode array, a photodiode array, a transducer, or the like. Can be deployed.

The method for manufacturing a solar cell of the present invention includes the method for manufacturing a semiconductor element of the present invention.

An example of a method for obtaining a solar cell by the method for manufacturing a solar cell of the present invention from a semiconductor element obtained by the method for manufacturing a semiconductor element of the present invention is as follows.

As a method for manufacturing a solar cell of the present invention, it is preferable to provide a passion film for suppressing surface recombination and preventing light reflection on the semiconductor device obtained by the method for manufacturing a semiconductor device of the present invention. _{For example, as the passivation film of the n-type diffusion layer, SiO 2} obtained by heat treatment in a high-temperature oxygen atmosphere of 700 ° C. or higher, and a silicon nitride film may be provided to protect this film. Further, _{only the SiN x} film may be formed. In this case, it can be formed by a plasma CVD method using a mixed gas of _{SiH 4} and NH _{3 as a raw material.} At this time, hydrogen diffuses into the crystal, and the orbitals that do not contribute to the bonding of silicon atoms, that is, the dangling bond and hydrogen are bonded to inactivate the defect (hydrogen passivation). More specifically, the mixed gas flow rate ratio NH ₃ / SiH ₄ is 0.05 to 1.0, the pressure in the reaction chamber is 13.3 to 266.6 Pa (0.1 to 2 Torr), and the temperature at the time of film formation is It is formed under the conditions of 300 ° C. to 550 ° C. and a frequency of 100 kHz or more for discharging plasma.

Then, the metal paste for the light receiving surface electrode and the metal paste on the passivation film of the n-type diffusion layer are printed on the antireflection film on the light receiving surface by a screen printing method and dried to form the light receiving surface electrode. The metal paste for the light receiving surface electrode contains metal particles and glass particles as essential components, and if necessary, contains a resin binder, other additives, and the like. As the metal paste used at this time, it is preferable to apply one suitable for the p-type diffusion layer and one suitable for the n-type diffusion layer, respectively. As the metal particles, Ag and Al are preferably used.

Then, the electrodes are heat-treated (fired) to complete the solar cell element. When heat-treated (fired) for several seconds to several minutes in the range of 600 ° C to 900 ° C, the antireflection film, which is an insulating film, is melted by the glass particles contained in the metal paste for the electrode on the light receiving surface side, and the silicon surface is also partially melted. Then, the metal particles (for example, silver particles) in the paste form a contact portion with the semiconductor substrate and solidify. As a result, the formed light-receiving surface electrode and the semiconductor substrate are made conductive. This is called fire-through.

The light receiving surface electrode is generally composed of a bus bar electrode and a finger electrode intersecting the bus bar electrode. Such a light receiving surface electrode can be formed by means such as screen printing of the above-mentioned metal paste, plating of the electrode material, and vapor deposition of the electrode material by heating an electron beam in a high vacuum. The busbar electrode and the finger electrode can be formed by a known method.

Examples Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Of the compounds used, those using abbreviations are shown below.

KBM-13: Methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)
KBM-103: Phenyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)
GBL: γ-Butyrolactone BYK-333: Silicone-based surfactant (manufactured by Big Chemi Co., Ltd.)
SH30PA: Silicone surfactant (manufactured by Toray Dow Corning Co., Ltd.)
<Evaluation method>
Sheet resistance value (surface resistance value) uniformity (impurity diffusion concentration uniformity)
With respect to the semiconductor substrates obtained from Examples 1 to 14 and Comparative Examples 1 to 4 in which the impurity diffusion composition was removed, the surface resistance values were set to the four-probe type surfaces at the locations (A to D, E to M) shown in FIG. The measurement was performed using a resistance measuring device RT-70V (manufactured by Napson Corporation).

The average value, maximum value, and minimum value for A to D are A1, B1, C1, and the average value, maximum value, and minimum value for E to M are A2, B2, and C2, and the variation (B1-C1) / A1 × If the values of 100 and (B2-C2) / A2 × 100 were both within 20%, it was passed, and if it exceeded 20%, it was rejected.

Formulation example 1
<Synthesis of polymer solution of silica compound>
164.93 g of KBM-13, 204.07 g of KBM-103, and 363.03 g of GBL were placed in a 2000 mL three-necked flask, and 30 formic acid aqueous solutions in which 1.215 g of formic acid was dissolved in 130.76 g of water while stirring at 40 ° C. Added over minutes. After completion of the dropping, the mixture was stirred at 40 ° C. for 1 hour, then heated to 70 ° C. and stirred for 30 minutes. Then, the temperature of the oil bath was raised to 115 ° C. The internal temperature of the solution reached 100 ° C. 1 hour after the start of temperature rise, and the mixture was heated and stirred for 1 hour (internal temperature was 100 to 110 ° C.). The obtained solution was cooled in an ice bath to obtain a polymer of a silica compound. The solid content concentration of the polymerization solution was 39.8% by mass.
<Preparation of p-type impurity diffusion composition>
4.39 g of the silica compound polymer synthesized above, 1.47 g of boric acid, 12.55 g of GBL, and BYK-333 were added so as to be 300 ppm with respect to the whole solution, and the mixture was sufficiently stirred to be uniform. A p-type impurity diffusion composition A was obtained.

Formulation example 2
<Synthesis of polymer solution of silica compound>
112.47 g of 3-glycidyloxypropyltrimethoxysilane and 130.47 g of diethylene glycol monomethyl ether were charged in a 500 mL three-necked flask, and the temperature was raised to 40 ° C. by heating. Then, a mixed solution of 0.24 g of concentrated sulfuric acid and 42.83 g of water was added dropwise. After the dropping addition was completed, stirring was continued at 40 ° C. for 1 hour. Then, the temperature was raised to 70 ° C., and the mixture was stirred for 1 hour and 20 minutes. Then, the temperature was raised to 100 ° C. and the mixture was stirred for 1 hour. Then, the oil bath temperature was raised to 120 ° C. and stirred. After stirring at 120 ° C. for 1 hour, the mixture was cooled to 40 ° C. or lower to obtain a polymer solution of a silica compound.
<Preparation of p-type impurity diffusion composition>
58.55 g of 3-methoxy-3-methylbutanol and 4.22 g of polyvinyl alcohol (manufactured by Japan Vam & Poval Co., Ltd .: degree of polymerization 300, degree of saponification 85%) were sequentially added to a 500 mL three-necked flask. The temperature was raised to 80 ° C. by heating, and 36.00 g of water was added dropwise. After the dropping addition was completed, stirring was continued at 80 ° C. until the polyvinyl alcohol was completely dissolved. Then, 0.73 g of boron trioxide was added, and stirring was continued at 80 ° C. for 1 hour. Then, the mixture was cooled to 40 ° C. or lower, and 20 g of the polymer solution of the silica compound synthesized above was added dropwise. The mixture was continuously stirred for 1 hour to obtain a p-type impurity diffusion composition B.

Formulation example 3
<Preparation of p-type impurity diffusion composition>
73.74 g of water, 113.4 g of propylene glycol monomethyl ether, and 9.3 g of polyvinyl alcohol (manufactured by Japan Vam & Poval Co., Ltd .: degree of polymerization 300, degree of saponification 85%) were sequentially added to a 300 mL three-necked flask. .. The temperature was raised to 80 ° C. by heating, and stirring was continued at 80 ° C. until the polyvinyl alcohol was completely dissolved. Then, 1.793 g of diboron trioxide was added, and stirring was continued at 80 ° C. for 1 hour. Then, the mixture was cooled to 40 ° C. or lower, 0.01 g of SH30PA was added, and the mixture was further stirred for 1 hour to obtain a p-type impurity diffusion composition C.

Formulation example 4
<Synthesis of particles containing impurity diffusion components>
B ₂ O _3, the composition molar ratio of _SiO 2, _Al 2 _{O 3} and CaO, respectively 40 mol%, 45 mol%, such that 5 mol% and _{10mol%, B 2 O 3,} SiO 2, Al 2 O 3 and And CaSO ₄ (all manufactured by High Purity Chemical Laboratory Co., Ltd.) were weighed. After mixing in an agate mortar, the mixture was placed in a platinum crucible and kept at 1500 ° C. for 2 hours in a glass melting furnace. Then, it was rapidly cooled to obtain a glass block. This was pulverized in an agate mortar and then pulverized in a planetary ball mill to obtain glass particles having a spherical particle shape, an average particle size of 0.35 μm, and a softening point of about 800 ° C.
<Preparation of p-type impurity diffusion composition>
10 g of the above glass particles, 6 g of ethyl cellulose and 84 g of terpineol were mixed and made into a paste to obtain a p-type impurity diffusion composition D.

Formulation example 5
<Preparation of p-type impurity diffusion composition>
4.39 g of GBL solution of trimethoxysilane having a concentration of 40%, 1.47 g of boric acid, 12.55 g of GBL, and BYK-333 were added so as to be 300 ppm with respect to the whole solution, and the mixture was sufficiently stirred to be uniform. Then, a p-type impurity diffusion composition E was obtained.

Formulation example 6
<Synthesis of polymer solution of silica compound>
183.25 g of KBM-13 (methyltrimethoxysilane), 266.75 g of KBM-103 (phenyltrimethoxysilane), and 403.36 g of GBL were placed in a 2000 mL three-necked flask, and 145.29 g of water was added while stirring at 40 ° C. An aqueous solution of formic acid in which 0.45 g of formic acid was dissolved was added over 30 minutes. After completion of the dropping, the mixture was stirred at 40 ° C. for 1 hour, then heated to 70 ° C. and stirred for 30 minutes. Then, the temperature of the oil bath was raised to 115 ° C. The internal temperature of the solution reached 100 ° C. 1 hour after the start of temperature rise, and the mixture was heated and stirred for 1 hour (internal temperature was 100 to 110 ° C.). The obtained solution was cooled in an ice bath to obtain a polymer solution of a silica compound.
<Preparation of p-type impurity diffusion composition>
13.42 g of the polymer of the silica compound synthesized above, 1.31 g of boric acid, and polyvinyl alcohol having a saponification degree of 49% (manufactured by Japan Vam & Poval Co., Ltd.) (hereinafter referred to as polyvinyl alcohol (49)). ) 11.63 g, 3.9 g of Aerosil VPNKC130 (manufactured by Nippon Aerosil Co., Ltd.), which is fine silicon oxide, 24.64 g of GBL, 35.1 g of terpineol, and 10 g of water are mixed and sufficiently stirred so as to be uniform. Then, a p-type impurity diffusion composition F was obtained.

Formulation example 7
A p-type impurity diffusion composition G was obtained in the same manner as in Formulation Example 6, except that the degree of saponification of polyvinyl alcohol was 70%.

Example 1
As a substrate, a semiconductor substrate made of n-type single crystal silicon having a side of 156 mm was prepared, and both surfaces were alkali-etched in order to remove slice damage and natural oxides. At this time, innumerable irregularities having a typical width of 40 to 100 μm and a depth of about 3 to 4 μm were formed on both sides of the semiconductor substrate, and these were used as coated substrates (sheet resistance value: 200 Ω / □).

Here, the p-type impurity diffusion composition A was printed by screen printing. The printing pattern was aligned so that 4 cm x 4 cm squares were arranged as shown in Fig. 3 (screen printing machine (Microtech Co., Ltd. TM-750 type), screen mask (manufactured by SUS Co., Ltd., 400). Mesh, wire diameter 23 μm)).

After screen printing the p-type impurity diffusion composition, the substrate was heated in air on a hot plate at 140 ° C. for 5 minutes and then in an oven at 230 ° C. for 30 minutes to form a pattern having a thickness of about 1.5 μm. ..

Next, this patterned substrate was placed in a diffusion furnace (manufactured by Koyo Thermo Systems Co., Ltd.) and maintained at 950 ° C. for 30 minutes in an atmosphere of nitrogen 19 L / min and oxygen 0.6 L / min to form an impurity diffusion layer. Formed. As it is, the temperature inside the furnace is lowered to 920 ° C., and impurities are diffused in the furnace by bubbling nitrogen 19 L / min, oxygen 0.06 L / min, and boron bromide (BBr _{3) with nitrogen 0.06 L / min.} An atmosphere containing components was created, and impurities were diffused in the unpatterned portion. After completion of the diffusion, the substrate was immersed in a 5% hydrofluoric acid solution for 5 minutes, washed with water to remove the impurity diffusion film, and the sheet resistance value was measured.

Example 2
The same coated substrate as in Example 1 was used.

Here, using the p-type diffusion layer forming composition A, a pattern having a thickness of about 1.5 μm was formed in the same manner as in Example 1.

Then, this patterned substrate was placed in an ion implanter at an energy of 10 ^keV, ions were implanted at a dose of between 2e 15 1 / cm ^2. Then, the patterned substrate was placed in a diffusion furnace and maintained at 950 ° C. for 30 minutes in an atmosphere of nitrogen 19 L / min and oxygen 0.6 L / min to form an impurity diffusion layer. After completion of the diffusion, the substrate was immersed in a 5% hydrofluoric acid solution for 5 minutes, washed with water to remove the impurity diffusion film, and the sheet resistance value was measured.

Example 3
The same coated substrate as in Example 1 was used.

Here, using the p-type diffusion layer forming composition A, a pattern having a thickness of about 1.5 μm was formed in the same manner as in Example 1.

Next, this patterned substrate was placed in a diffusion furnace (manufactured by Koyo Thermo Systems Co., Ltd.), and nitrogen 19 L / min, oxygen 0.06 L / min, and boron bromide (BBr ₃ ) at nitrogen 0.06 L / min. By bubbling and flowing, the inside of the furnace was made to have an atmosphere containing an impurity diffusion component, and the pattern-formed portion and the pattern-unformed portion were simultaneously diffused at 950 ° C. for 30 minutes. After completion of the diffusion, the substrate was immersed in a 5% hydrofluoric acid solution for 5 minutes, washed with water to remove the impurity diffusion film, and the sheet resistance value was measured.

Example 4
The same coated substrate as in Example 1 was used.

Here, using the p-type diffusion layer forming composition A, a pattern having a thickness of about 1.5 μm was formed in the same manner as in Example 1.

The p-type impurity diffusion composition B was spin-coated on this substrate at a rotation speed of 500 nm and applied to the entire surface, and the substrate was heated in air on a hot plate at 140 ° C. for 5 minutes.

This patterned substrate was placed in a diffusion furnace (manufactured by Koyo Thermo Systems Co., Ltd.), and under an atmosphere of 19 L / min of nitrogen and 0.6 L / min of oxygen, 30 minutes at 950 ° C. Impurity diffusion was performed at the same time. After completion of the diffusion, the substrate was immersed in a 5% hydrofluoric acid solution for 5 minutes, washed with water to remove the impurity diffusion film, and the sheet resistance value was measured.

Example 5
The sheet resistance value was measured in the same manner as in Example 4 except that the p-type impurity diffusion composition B was changed to the p-type impurity diffusion composition C.

Example 6
The same coated substrate as in Example 1 was used.

This substrate is placed in a diffusion furnace (manufactured by Koyo Thermo Systems Co., Ltd.), and nitrogen 19 L / min, oxygen 0.06 L / min, and boron bromide (BBr ₃ ) are bubbled with nitrogen 0.06 L / min and flowed. The inside of the furnace was made to have an atmosphere containing an impurity diffusion component, and impurities were diffused over the entire surface of the substrate at 920 ° C. for 30 minutes.

Then, using the p-type diffusion layer forming composition A on this substrate, a pattern having a thickness of about 1.5 μm was formed in the same manner as in Example 1.

Next, this patterned substrate was placed in a diffusion furnace (manufactured by Koyo Thermo Systems Co., Ltd.) and maintained at 950 ° C. for 30 minutes in an atmosphere of nitrogen 19 L / min and oxygen 0.6 L / min to form an impurity diffusion layer. Formed. After the diffusion was completed, the substrate was immersed in a 5% hydrofluoric acid solution for 5 minutes, washed with water to remove the impurity diffusion film, and the sheet resistance value was measured. Example 7
The same coated substrate as in Example 1 was used.

The substrate was placed in an ion implanter at an energy of 10 ^keV, ions were implanted at a dose of between 2e 15 1 / cm ^2. Then, the substrate was placed in a diffusion furnace and maintained at 920 ° C. for 30 minutes in a nitrogen atmosphere to form an impurity diffusion layer.

Then, using the p-type diffusion layer forming composition A on this substrate, a pattern having a thickness of about 1.5 μm was formed in the same manner as in Example 1.

Next, this patterned substrate was placed in a diffusion furnace (manufactured by Koyo Thermo Systems Co., Ltd.) and placed in a diffusion furnace (manufactured by Koyo Thermo Systems Co., Ltd.) with nitrogen 19 L / min and oxygen 0.6 L / min. An impurity diffusion layer was formed by maintaining the temperature at 950 ° C. for 30 minutes under an atmosphere. After completion of the diffusion, the substrate was immersed in a 5% hydrofluoric acid solution for 5 minutes, washed with water to remove the impurity diffusion film, and the sheet resistance value was measured.

Example 8
The same coated substrate as in Example 1 was used.

The p-type impurity diffusion composition B was spin-coated on this substrate at a rotation speed of 500 nm and applied to the entire surface, and the substrate was heated in air on a hot plate at 140 ° C. for 5 minutes.

Then, using the p-type diffusion layer forming composition A on this substrate, a pattern having a thickness of about 1.5 μm was formed in the same manner as in Example 1.

Next, this patterned substrate was placed in a diffusion furnace (manufactured by Koyo Thermo Systems Co., Ltd.) and maintained at 950 ° C. for 30 minutes in an atmosphere of nitrogen 19 L / min and oxygen 0.6 L / min to form an impurity diffusion layer. Formed. After completion of the diffusion, the substrate was immersed in a 5% hydrofluoric acid solution for 5 minutes, washed with water to remove the impurity diffusion film, and the sheet resistance value was measured.

Example 9
The sheet resistance value was measured in the same manner as in Example 1 except that the p-type impurity diffusion composition A was changed to the p-type impurity diffusion composition F.

Example 10
The sheet resistance value was measured in the same manner as in Example 2 except that the p-type impurity diffusion composition A was changed to the p-type impurity diffusion composition F.

Example 11
The sheet resistance value was measured in the same manner as in Example 3 except that the p-type impurity diffusion composition A was changed to the p-type impurity diffusion composition F.

Example 12
The sheet resistance value was measured in the same manner as in Example 4 except that the p-type impurity diffusion composition A was changed to the p-type impurity diffusion composition F.

Example 13
The sheet resistance value was measured in the same manner as in Example 5 except that the p-type impurity diffusion composition A was changed to the p-type impurity diffusion composition F.

Example 14
The sheet resistance value was measured in the same manner as in Example 1 except that the p-type impurity diffusion composition A was changed to the p-type impurity diffusion composition G.

Comparative Example 1
The sheet resistance value was measured in the same manner as in Example 1 except that the p-type impurity diffusion composition A was changed to the p-type impurity diffusion composition D.

Comparative Example 2
The sheet resistance value was measured in the same manner as in Example 1 except that the p-type impurity diffusion composition A was changed to the p-type impurity diffusion composition E.

Comparative Example 3
The sheet resistance value was measured in the same manner as in Example 1 except that boron bromide (BBr ₃ ) was stopped to create an atmosphere containing an impurity diffusion component in the furnace.

Comparative Example 4
The sheet resistance value was measured in the same manner as in Example 4 except that the p-type impurity diffusion composition B was not applied to the substrate on which the pattern of the p-type diffusion layer forming composition A was formed.

The evaluation results are shown in Table 1.

1 Semiconductor substrate 2 Ion implantation 3 Impurity diffusion component-containing gas 4 Impurity diffusion composition film (b) pattern

Claims (16)

A method for manufacturing a semiconductor element in which the same type of impurity diffusion layer region is formed on a semiconductor substrate at two or more levels of different impurity concentrations. Among them, at least one level or more of the impurity diffusion layer region is an impurity diffusion composition (a). ) Is applied to the semiconductor substrate to partially form the impurity diffusion composition film (b), and the step of heating it to diffuse the impurities to the semiconductor substrate to form the impurity diffusion layer region (c) is included. A method for producing a semiconductor element, which is formed by a method and contains (a-1) a polymer of a silane compound represented by the following general formula (1), and (a-2) an impurity diffusion component.

(In the general formula (1), R ¹ and R ² are hydroxyl groups, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, and acyloxy having 2 to 6 carbon atoms. It represents either a group or an aryl group having 6 to 15 carbon atoms, and the plurality of R ¹ and R ² may be the same or different, respectively. L _{1 represents an integer of 1 to 10000.)} The method for producing a semiconductor device according to claim 1, wherein the polymer of the silane compound is a polymer of the silane compound represented by the following general formula (2).

(In the general formula (2), R ³ represents an aryl group having 6 to 15 carbon atoms, and a plurality of R ³ may be the same or different. R ⁴ is a hydroxyl group and an alkyl group having 1 to 6 carbon atoms. , an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms, even more ^{R 4} are respectively the same ^{R 5} and R ⁶ may be a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and an acyloxy group having 2 to 6 carbon atoms. Either of them may be represented, and a plurality of R ⁵ and R ⁶ may be the same or different. N ₁ , m ₁ represents an integer of _{1 to 9999, n 1} + m ₁ is an integer of 2 to 10000, and n ₁ : m ₁ = 95: 5 to 25:75.) The method for producing a semiconductor device according to claim 2, wherein the impurity diffusion composition (a) further contains (a-3) polyvinyl alcohol having a saponification degree of 20 mol% or more and less than 50 mol%. The method for manufacturing a semiconductor device according to any one of claims 1 to 3, further comprising a step of diffusing impurities into an impurity diffusion composition film (b) unformed portion using the impurity diffusion composition film (b) as a mask. In the step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b), the impurity diffusion composition film (b) was heated to diffuse the impurities to the semiconductor substrate to form the impurity diffusion layer region (c). The method for manufacturing a semiconductor element according to claim 4, which will be described later. The semiconductor according to claim 4, wherein the step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) is performed at the same time as the step of heating the impurity diffusion composition film (b) to diffuse impurities to the semiconductor substrate. Method of manufacturing the element. The method for manufacturing a semiconductor device according to claim 5 or 6, wherein the step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) is a step of injecting ions containing an impurity diffusion component. The method for manufacturing a semiconductor device according to claim 5 or 6, wherein the step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) is a step of heating in an atmosphere containing an impurity diffusion component. The step of diffusing impurities into the non-formed portion of the impurity diffusion composition film (b) is to apply the impurity diffusion composition (d) to the impurity diffusion composition film (d) on the semiconductor substrate on which the impurity diffusion composition film (b) is formed. b) The method for manufacturing a semiconductor element according to claim 5 or 6, which is a step of heating an impurity diffusion composition film (e) formed by coating on an unformed portion. A step of injecting ions containing an impurity diffusion component onto a semiconductor substrate, a step of heating in an atmosphere containing an impurity diffusion component, and an impurity diffusion composition film (e) formed by fully coating the impurity diffusion composition (d). ) Is formed by using at least one step selected from the group consisting of heating steps, and then the impurity diffusion composition (a) is applied to partially form the impurity diffusion composition. The method for manufacturing a semiconductor element according to any one of claims 1 to 3, which includes a step of forming a film (b) and a step of heating the film to diffuse impurities on a semiconductor substrate to form an impurity diffusion layer region (c). .. The impurity diffusion composition (d) is entirely coated on the semiconductor substrate to form the impurity diffusion composition film (e), and the impurity diffusion composition (a) is coated thereto to partially coat the impurity diffusion composition film. 4. Method for manufacturing semiconductor elements. The method for producing a semiconductor device according to any one of claims 9 to 11, wherein the impurity diffusion composition (d) contains a polymer of (d-1) a silane compound and (d-2) an impurity diffusion component. (D-1) The method for producing a semiconductor device according to claim 12, wherein the polymer of the silane compound is a polymer of the silane compound represented by the following general formula (3).

(In the general formula (3), R ⁷ and R ⁸ are hydroxyl groups, alkyl groups having 1 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, and acyloxy having 2 to 6 carbon atoms. A group represents any of an aryl group having 6 to 15 carbon atoms, and a plurality of R ⁷ and R ⁸ may be the same or different _{, respectively. L 2} represents an integer of 1 to 10000.) (D-1) The method for producing a semiconductor device according to claim 12, wherein the polymer of the silane compound is a polymer of the silane compound represented by the following general formula (4).

(In the general formula (4), ^{R 9} is an aryl group having from 6 to 15 carbon atoms, a plurality of ^{R 9} is optionally the same or different ^{.R 10} is a hydroxyl group, an alkyl group having 1 to 6 carbon atoms , an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms, even more ^{R 10} is the same as each ^{R 11} and R ¹² may be different: a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and an acyloxy group having 2 to 6 carbon atoms. A plurality of R ¹¹ and R ¹² may be the same or different, respectively. N ₂ and m ₂ represent an integer of 1 to 9999, n ₂ + m ₂ is an integer of 2 to 10000, and n ₂ : m ₂ = 95: 5 to 25:75.) The impurity diffusion composition (d) contains at least one resin (d-5) impurity diffusion component selected from the group consisting of (d-4) polyvinyl alcohol and polyether oxide, and (d-6) solvent. The method for producing a semiconductor device according to any one of claims 9 to 11, wherein 25% by mass or more of the total solvent is water. A method for manufacturing a solar cell, which comprises the method for manufacturing a semiconductor device according to any one of claims 1 to 15.

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