JPWO2020116270A1 - P-type impurity diffusion composition and its manufacturing method, semiconductor device manufacturing method using it, and solar cell - Google Patents

Abstract

An object of the present invention is to provide a p-type impurity diffusion composition capable of uniform diffusion on a semiconductor substrate and improvement of storage stability of a coating liquid.
(A) At least one resin selected from polyvinyl alcohol and polyethylene oxide,
A p-type impurity diffusion composition containing (b) a solvent and (c) a compound containing a Group 13 element, wherein the pH of the composition is 4 to 6.5, and (b) the solvent is (b-). 1) It contains an organic solvent having a boiling point of 110 ° C. or higher and 210 ° C. or lower and (b-2) water, and the amount of (b-2) water is 10 to 50% by mass in the (b) solvent. P-type impurity diffusion composition.
[Selection diagram] None

Description

The present invention relates to a composition for diffusing p-type impurities in a semiconductor substrate, a method for producing the same, a method for producing a semiconductor element using the same, and a solar cell.

Currently, in the manufacture of solar cells, as a main method for forming a p-type or n-type impurity diffusion layer in a semiconductor substrate, _{a gas such as BBr 3 or the like in the case of p-type and POCl 3} or the like in the case of n-type is used as the substrate. The method of heating while contacting with is adopted.

On the other hand, in recent years, a method of forming an impurity diffusion layer by applying a composition containing a p-type or n-type impurity component on a substrate and diffusing it by heat has been studied. Hereinafter, the diffusion of impurities into the substrate by heat from the composition containing the impurity component coated on the substrate may be referred to as thermal diffusion.

The impurity diffusion composition (hereinafter referred to as p-type impurity diffusion composition) that forms a p-type impurity diffusion layer is formed by blending a compound containing a Group 13 element such as boron with a resin such as polyvinyl alcohol to form a complex. Is obtained by dissolving or dispersing the mixture in a solvent. Such a composition is designed so that it can be applied to a semiconductor substrate by a spin coating method, a screen printing method, or the like. If the wettability to the substrate is good, the uniformity of the film thickness of the coating film obtained after removing the solvent is good. Therefore, the solvent is preferably an organic solvent having a low surface tension, but the Group 13 element. Since a resin such as polyvinyl alcohol in which a compound containing a compound containing a compound is mixed to form a complex is often a water-soluble resin, the solvent of the actual composition is often a mixture of water and an organic solvent (for example). See Patent Documents 1-5).

Japanese Patent No. 3519847 Japanese Unexamined Patent Publication No. 2007-35719 JP-A-2010-62223 Japanese Unexamined Patent Publication No. 2010-161317 Japanese Unexamined Patent Publication No. 9-181009

When the solvent is a mixture of water and an organic solvent, the complex of the compound containing the Group 13 element and polyvinyl alcohol becomes unstable, the uniformity of the film thickness of the obtained coating film is lowered, and impurities are diffused. There are problems that the in-plane uniformity of the sheet resistance value (impurity diffusion concentration) of the substrate is lowered and the viscosity changes with time during storage of the p-type impurity diffusion composition.

The present invention has been made based on the above circumstances, and is to uniformly diffuse impurities into a semiconductor substrate, improve the uniformity of the film thickness of the coating film, and improve the storage stability of the composition. It is an object of the present invention to provide a p-type impurity diffusion composition capable of the above.

In order to solve the above problems, the p-type impurity diffusion composition of the present invention has the following constitution. That is,
(A) At least one resin selected from polyvinyl alcohol and polyethylene oxide,
A p-type impurity diffusion composition containing a solvent and a compound containing a Group 13 element (b), wherein the pH of the p-type impurity diffusion composition is 4 to 6.5, and (b) a solvent. However, it contains (b-1) an organic solvent having a boiling point of 110 ° C. or higher and 210 ° C. or lower and (b-2) water, and the amount of (b-2) water is 10 to 50% by mass in the solvent (b). It is a p-type impurity diffusion composition characterized by being present.

According to the present invention, it is possible to provide a p-type impurity diffusion composition which is excellent in the uniformity of impurity diffusion to a semiconductor substrate and the uniformity of the film thickness of a coating film and has high storage stability.

It is a process cross-sectional view which shows an example of the method of forming the impurity diffusion layer using the p-type impurity diffusion composition of this invention. It is a process cross-sectional view which shows an example of the method of forming the impurity diffusion layer using the p-type impurity diffusion composition of this invention. It is a process cross-sectional view which shows an example of the manufacturing method of the back surface bonding type solar cell using the p-type impurity diffusion composition of this invention. It is a process cross-sectional view which shows another example of the method of forming the impurity diffusion layer using the p-type impurity diffusion composition of this invention. It is a process cross-sectional view which shows another example of the method of forming the impurity diffusion layer using the p-type impurity diffusion composition of this invention. It is a process cross-sectional view which shows another example of the method of forming the impurity diffusion layer using the p-type impurity diffusion composition of this invention.

The p-type impurity diffusion composition of the present invention is
(A) At least one resin selected from polyvinyl alcohol and polyethylene oxide,
A p-type impurity diffusion composition containing (b) a solvent and (c) a compound containing a Group 13 element, wherein the pH of the composition is 4 to 6.5, and (b) the solvent is (b-). 1) It contains an organic solvent having a boiling point of 110 ° C. or higher and 210 ° C. or lower and (b-2) water, and the amount of (b-2) water is 10 to 50% by mass in the (b) solvent. It is a p-type impurity diffusion composition.

(A) At least one resin selected from polyvinyl alcohol and polyethylene oxide (hereinafter, may be simply referred to as "(a) resin").
The p-type impurity diffusion composition of the present invention contains (a) at least one resin selected from polyvinyl alcohol and polyethylene oxide. The resin (a) is a component for forming a complex with a compound containing a Group 13 element (c) to form a uniform coating film at the time of coating. (C) Polyvinyl alcohol is preferable from the viewpoint of the formability of the complex with the compound containing the Group 13 element and the stability of the formed complex.

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 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 saponification degree is a value measured by the back titration method in the JIS.

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

Further, the amount of the resin (a) is the composition in terms of (c) good thermal diffusion of the compound containing the Group 13 element to the semiconductor substrate and suppression of organic residues on the substrate after removal of the composition. It is preferably 0.1 to 20% by mass, more preferably 1 to 10% by mass, when the whole product is 100% by mass.

(B-1) Organic solvent having a boiling point of 110 ° C. or higher and 210 ° C. or lower (hereinafter, may be simply referred to as “(b-1) organic solvent”).
The p-type impurity diffusion composition of the present invention contains (b-1) an organic solvent having a boiling point of 110 ° C. or higher and 210 ° C. or lower. (B-1) When the boiling point of the organic solvent is in this range, after applying the p-type impurity diffusion composition to the semiconductor substrate, the complex composed of (c) a compound containing a Group 13 element and (a) a resin is dissolved. (B) Water contained in the solvent (b) and (b-1) organic solvent volatilize in a well-balanced manner to obtain a coating film having excellent film thickness uniformity and impurity diffusion concentration uniformity. Can be done.

(B-1) The boiling point range of the organic solvent is preferably 120 ° C. or higher and 185 ° C. or lower, more preferably 165 ° C. or higher and 180 ° C. or lower.

Specific examples of the organic solvent (b-1) include dimethylformamide (boiling point 153 ° C., the same applies hereinafter), diethylene glycol monomethyl ether (193 ° C.), 1-butanol (118 ° C.), cyclohexanol (161 ° C.), ethylene glycol mono. Ethyl ether acetate (156.4 ° C), ethylene glycol monomethyl ether acetate (145 ° C), methyl lactate (145 ° C), ethyl lactate (155 ° C), diacetone alcohol (169 ° C), 3-methoxy-3-methyl- 1-butanol (174 ° C), dipropylene glycol monomethyl ether (188 ° C), γ-butyrolactone (204 ° C), ethyl acetoacetate (181 ° C), N-methyl-2-pyrrolidone (204 ° C), propylene glycol t- Butyl ether (151 ° C), propylene glycol n-butyl ether (170 ° C), acetylacetone (140 ° C), diethylene glycol monobutyl ether (171 ° C), furfuryl alcohol (170 ° C), 1,3-butanediol (207 ° C), diethylene glycol Ethylmethyl ether (176 ° C), propylene glycol monomethyl ether acetate (145 ° C), diisobutyl ketone (168 ° C), ethylene glycol (197 ° C), propylene glycol (188 ° C), propylene glycol monomethyl ether (120 ° C), etc. Can be mentioned.

(C) Organic solvent (b-1) in that the compatibility between the compound containing the Group 13 element and the complex composed of (a) resin is further improved, and the uniformity of the film thickness of the coating film is further improved. Is more preferably a primary alcohol, and particularly preferably 3-methoxy-3-methyl-1-butanol.

The p-type impurity diffusion composition is in that the complex formed from the compound (c) containing the Group 13 element and the resin (a) is more stable and the storage stability of the p-type impurity diffusion composition is better. The amount of the (b-1) organic solvent contained therein is preferably 50 to 90% by mass in the (b) solvent. It is more preferably (b) 55 to 85% by mass in the solvent, and even more preferably (b) 65 to 80% by mass in the solvent.

(B-2) Water The p-type impurity diffusion composition of the present invention contains (b-2) water. The amount of (b-2) water is 10 to 50% by mass in the solvent (b). Within this range, the complex formed from (c) the compound containing the Group 13 element and (a) the resin is stable, and the p-type impurity diffusion composition has excellent storage stability. The amount of (b-2) water is preferably 15 to 45% by mass in the solvent (b), and more preferably 20 to 35% by mass in the solvent (b).

From the above, as the solvent, the boiling point of the organic solvent (b-1) is 120 ° C. or higher and 185 ° C. or lower, and the amount of water (b-2) is 15 to 45 in the solvent (b). It is preferably mass%, (b-1) the boiling point of the organic solvent is 165 ° C. or higher and 180 ° C. or lower, and (b-2) the amount of water is 15 to 45% by mass in the solvent (b). (B-1) The boiling point of the organic solvent is 165 ° C. or higher and 180 ° C. or lower, and (b-2) the amount of water is (b) 20 to 35% by mass in the solvent. It is more preferable to have.

(C) Compounds containing Group 13 elements
The p-type impurity diffusion composition of the present invention contains (c) a compound containing a Group 13 element.

Examples of the Group 13 element include boron, aluminum, gallium, indium, thallium, and nihonium, and boron is preferably used from the viewpoint of diffusivity to a semiconductor substrate.

Specific examples of the boron-containing compound include boric acid, boric acids such as diboron trioxide, borates such as ammonium borate, boron trifluoride, boron trichloride, boron tribromide, and triiodide. Halogens such as boron, boric acids such as methylboronic acid and phenylboronic acid, trimethylborate, triethyl borate, tripropyl borate, tributyl borate, trioctyl borate, triphenyl borate and other borate esters. be able to. Of these, boric acids, boronic acids and boric acid esters are preferable in terms of ease of handling.

The amount of the (c) Group 13 element compound contained in the p-type impurity diffusion composition can be arbitrarily determined by the resistance value required for the semiconductor device, but is 0.05 with respect to the p-type impurity diffusion composition. It is preferably contained in an amount of ~ 1% by mass. More preferably, it is 0.1 to 0.5% by mass.

Further, from the viewpoint of storage stability of the p-type impurity diffusion composition, it is more preferable that the mass ratio of (c) the compound containing the Group 13 element / (a) resin is 0.25 to 0.45.

(D) Surfactant
The p-type impurity diffusion composition of the present invention preferably contains (d) a surfactant. By including the surfactant, (c) the dispersibility of the compound containing the Group 13 element is improved, and (c) the complex formation between the compound containing the Group 13 element and (a) the resin becomes better. This makes it possible to reduce the organic residue on the substrate when the p-type impurity diffusion composition is removed after the compound (c) containing the Group 13 element is thermally diffused on the semiconductor substrate.

(D) As the surfactant, a fluorine-based surfactant, a silicone-based surfactant, an acrylic-based surfactant, or the like 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.

Commercially available fluorine-based surfactants include Megafuck F142D, F172, F173, F183, F444, F475, F477 (manufactured by Dainippon Ink and Chemicals Co., Ltd.), and Ftop. EF301, 303, 352 (above, manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC-430, FC-431 (above, manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surfron S-382, same SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, manufactured by Asahi Glass Co., Ltd.), BM-1000, BM-1100 (above, Yusho) There are fluorine-based surfactants such as NBX-15, FTX-218, and DFX-218 (manufactured by Neos Co., Ltd.).

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

Examples of commercially available acrylic surfactants include Polyflow 77 and Polyflow 75 (all manufactured by Kyoeisha Chemical Co., Ltd.).

In particular, (c) a silicone-based surfactant and / or acrylic-based compound from the viewpoint of improving thermal diffusion of the compound containing the Group 13 element to the semiconductor substrate and further reducing the organic residue after removing the composition. Surface active agents are more preferably used.

Further, from the viewpoint of (c) increasing the dispersibility of the compound containing the Group 13 element, better thermal diffusion to the semiconductor substrate, and further reducing the organic residue after removing the composition, (d) the surfactant / ( c) The mass ratio of the Group 13 element compounds is preferably 0.03 to 0.1. This ratio is more preferably 0.03 to 0.045.

(PH)
The pH of the p-type impurity diffusion composition of the present invention is 4 to 6.5. Within this range, the complex of (a) the resin and (c) the compound containing the Group 13 element is stabilized. Further, even if the composition is stored for a certain period of time and then used for diffusion, the in-plane uniformity of the impurity diffusion concentration is maintained well.

A more preferred range of pH is 4.5-5.5. Examples of the pH adjusting method include, but are not limited to, a method of adding an acid and a base to the composition and a method of adjusting the pH when impurities are reduced by an ion exchange resin as described later.

As the acid, inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid and organic acids such as acetic acid and oxalic acid are preferable, and sulfuric acid, nitric acid, acetic acid and oxalic acid containing no metal element or halogen are more preferable.

As the base, an organic amine containing no metal element or halogen is preferable.

In particular, from the viewpoint of further improving storage stability, a method of combining the addition of an organic amine with the addition of sulfuric acid, nitric acid, acetic acid or oxalic acid, or a method of combining the addition of an organic amine with the adjustment with an ion exchange resin is preferable.

Examples of the organic amine used include aromatic amines and aliphatic amines, but aliphatic amines which are highly basic and effective with a smaller amount of addition are preferable. A tertiary amine is more preferable from the viewpoint of suppressing side reactions with other components of the composition.

Specific examples of the aliphatic tertiary amine include, but are not limited to, trimethylamine, triethylamine, triisopropylamine, triisopropanolamine, triethanolamine, pyridine, piperazine, piperidine, pyrrolidine, ethylpiperidine, piperidineethanol and the like. .. Preferably, an aliphatic cyclic tertiary amine such as piperazine, piperidine, pyrrolidine, ethyl piperidine, or piperidine ethanol is used.

From the viewpoint of the pH adjusting effect, the content of the organic amine is preferably 0.01 to 2% by mass of the entire composition. More preferably, it is 0.02 to 0.5% by mass of the whole composition, and further preferably 0.03 to 0.1% by mass of the whole composition.

The pH in the present invention is a value measured using a pH meter (LAQUA F-71, manufactured by HORIBA, Ltd.). The pH is calibrated using the following five standard solutions (pH 2, 4, 7, 9, 12) among those specified in JIS Z 8802: 2011 “pH measurement method”.
○ pH2 standard solution (oxalate)
0.05 mol / L potassium oxalate aqueous solution ○ pH4 standard solution (phthalate)
0.05 mol / L potassium hydrogen phthalate aqueous solution ○ pH7 standard solution (neutral phosphate: a mixture of the following two aqueous solutions)
0.025 mol / L potassium dihydrogen phosphate aqueous solution 0.025 mol / L disodium hydrogen phosphate aqueous solution ○ pH 9 standard solution (borate)
0.01 mol / L sodium tetraborate (borax) aqueous solution ○ pH12 standard solution Saturated calcium hydroxide aqueous solution.

The p-type impurity diffusion composition of the present invention preferably has a sodium (Na) content of 0.05 ppm or less. As a method for reducing Na, a method of purifying each component of the composition by recrystallization, distillation, column separation, ion exchange, etc. is used, but a method using an ion exchange resin is preferable, and the method of the present invention is preferable. The method for producing the p-type impurity diffusion composition preferably includes a step of performing an ion exchange treatment with an ion exchange resin.

Regarding the step of ion-exchange treatment, the entire composition containing the components (a) to (c) or at least one of the components (a) to (c) is ion-exchanged with an ion exchange resin. Is raised. Since Na may be mixed in the process of the production process, it is most preferable to finally perform the ion exchange treatment in the state of the entire composition containing the components (a) to (c). As a specific method of ion exchange treatment, a p-type impurity diffusion composition is passed through a column packed with a cation exchange resin, and the cation exchange resin is added to the liquid of the p-type impurity diffusion composition and stirred. The ion exchange resin may be removed after the ion exchange, but the present invention is not limited to these.

In particular, when a cation exchange resin is used, the pH of the p-type impurity diffusion composition after ion exchange is less than 7, so that it is possible to adjust the pH to a target at the same time as reducing impurities.

As an ion exchange treatment method for adjusting the pH value to 4 to 6.5, a method of performing an ion exchange treatment in combination with a cation exchange resin and an anion exchange resin is preferable. As a combination method, a method in which a cation exchange resin and an anion exchange resin are appropriately mixed and filled in a column and a p-type impurity diffusion composition is passed through, or a column filled with a cation exchange resin and an anion exchange resin are used. There is a method of continuously passing the packed column through the column, but the method is not limited to these.

The viscosity of the p-type impurity diffusion composition of the present invention is not limited, and can be appropriately changed depending on the coating method and the film thickness to be obtained. Here, for example, when applied to coating by the spin coating method, which is one of the preferred coating forms, the viscosity of the p-type impurity diffusion composition is preferably 1 to 100 mPa · s, preferably 1 to 50 mPa · s. Is even more preferable. The viscosity 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-Measuring Method”.

The p-type impurity diffusion composition of the present invention is not particularly limited in solid content concentration, but is preferably in the range of 1% by mass or more and 10% by mass or less. This is because the storage stability is particularly good in this concentration range, and the film thickness at the time of coating is easily controlled, so that the desired diffusion concentration can be easily adjusted.

A method for forming an impurity diffusion layer using the p-type impurity diffusion composition of the present invention and a method for manufacturing a semiconductor element using the same will be described. The method for manufacturing a semiconductor device of the present invention includes a step of applying the above-mentioned p-type impurity diffusion composition to a semiconductor substrate to form a p-type impurity diffusion composition film, and a p-type impurity diffusion composition film from the p-type impurity diffusion composition film. Is a method for manufacturing a semiconductor device, which comprises a step of forming a p-type impurity diffusion layer on the semiconductor substrate. Here, the p-type impurity diffusion composition film is coated by volatilizing (b-1) an organic solvent and (b-2) water contained in (b) a solvent after applying the p-type impurity diffusion composition of the present invention. It is a film, and has been described as a coating film in the above-mentioned usage mode of the p-type impurity diffusion composition. Further, in the above description, in the step of applying the p-type impurity diffusion composition of the present invention to form the p-type impurity diffusion composition film, the organic solvent (b-1) and (b-1) contained in the solvent (b) and (b) are included. -2) An operation of volatilizing water is included (hereinafter, "coating and forming" includes an operation of volatilizing a solvent after coating. The same applies to the n-type impurity diffusion composition described later. do). Further, in the present invention, the p-type impurity diffusion composition membrane includes "p-type impurity diffusion composition" in the name, but (b) the amount of solvent is less than that of the p-type impurity diffusion composition of the present invention. Alternatively, (b) the composition is different in that it does not contain a solvent. Here, (b) a small amount of solvent means a state in which (b) a solvent is removed to the extent that the coating film (p-type impurity diffusion composition film) does not flow. Further, in the method for manufacturing a semiconductor device of the present invention, an n-type impurity diffusion composition is partially applied to a semiconductor substrate to form an n-type impurity diffusion composition film, and then the n-type impurity diffusion composition film is used as a mask. This is a method for manufacturing a semiconductor device, which comprises a step of applying a p-type impurity diffusion composition to a portion where the n-type impurity diffusion composition has not been applied to form a p-type impurity diffusion composition film. At this time, the n-type impurity diffusion composition film may be heated before the p-type impurity diffusion composition is applied to form the n-type impurity diffusion layer first, or the n-type or p-type impurity diffusion composition film may be formed first. The n-type impurity diffusion layer and the p-type impurity diffusion layer may be formed at the same time by collectively heating after forming the n-type impurity diffusion layer.

The n-type impurity diffusion composition is for forming an n-type impurity diffusion layer in a semiconductor substrate by containing an n-type impurity diffusion component in the composition. The n-type impurity diffusion component is preferably a compound containing an element of Group 15, and more preferably a phosphorus compound. 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.

Further, the method for manufacturing a semiconductor device of the present invention includes a step of applying the above-mentioned p-type impurity diffusion composition to one surface of a semiconductor substrate to form a p-type impurity diffusion composition film, and the other of the semiconductor substrate. By applying the n-type impurity diffusion composition to the surface of the surface to form an n-type impurity diffusion composition film and heating the p-type impurity diffusion composition film and the n-type impurity diffusion composition film at the same time. This is a method for manufacturing a semiconductor device, which comprises a step of forming a p-type impurity diffusion layer and an n-type impurity diffusion layer on the semiconductor substrate.

Further, the method for manufacturing a semiconductor device of the present invention includes a step of applying the above-mentioned p-type impurity diffusion composition to one surface of a semiconductor substrate to form a p-type impurity diffusion composition film, and a p-type impurity diffusion composition. A step of arranging the semiconductor substrates on which the film is formed so that the surfaces on which the p-type impurity diffusion composition film is formed are facing each other in a set of two, and the p-type from the p-type impurity diffusion composition film. A step of diffusing impurities into the semiconductor substrate to form a p-type impurity diffusion layer on the semiconductor substrate, and heating the semiconductor substrate in an atmosphere having a gas containing n-type impurities continuously as it is, the semiconductor. This is a method for manufacturing a semiconductor device, which comprises a step of diffusing n-type impurities on the other surface of a substrate to form an n-type impurity diffusion layer.

Hereinafter, a method for forming an impurity diffusion layer applicable to the method for manufacturing these semiconductor devices will be described with reference to the drawings. It should be noted that all of these are examples, and the methods applicable to the method for manufacturing a semiconductor device of the present invention are not limited to these.

FIG. 1 shows a method of forming an impurity diffusion layer by applying the p-type impurity diffusion composition of the present invention to a semiconductor substrate and diffusing p-type impurities from the p-type impurity diffusion composition onto the semiconductor substrate. First, as shown in FIG. 1A, after applying the p-type impurity diffusion composition of the present invention on the semiconductor substrate 1, the organic solvent (b-1) and (b-2) contained in the solvent (b) ) Water is volatilized to form the p-type impurity diffusion composition film 2.

The semiconductor substrate 1 includes, for example ^{, an n-type single crystal silicon having an impurity concentration of 10 15} to ¹⁶ atoms / cm ³ , a polycrystalline silicon, 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 1 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 method for applying the p-type impurity diffusion composition 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 p-type impurity diffusion composition by these methods, the applied p-type impurity diffusion composition is heated in a hot plate, oven, etc. in the range of 50 to 200 ° C. for 30 seconds to 30 minutes (b) solvent. The organic solvent (b-1) and water (b-2) contained in the above are volatilized and dried. The film thickness of the p-type impurity diffusion composition film 2 obtained after drying is preferably 100 nm or more from the viewpoint of diffusivity of the p-type impurities to the semiconductor substrate 1, and preferably 3 μm or less from the viewpoint of the residue after etching.

Next, as shown in FIG. 1B, the p-type impurity is diffused on the semiconductor substrate 1 to form the p-type impurity diffusion layer 3. As a method for diffusing p-type impurities to a semiconductor substrate, a known method by thermal diffusion 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 the concentration of p-type impurities and the diffusion depth of p-type impurities in the obtained p-type impurity diffusion layer. For example, a p-type diffusion layer having ^{a surface impurity concentration of 10 19} to 10 ²¹ can be formed by heating and diffusing at 800 ° C. or higher and 1200 ° C. or lower for 1 to 120 minutes.
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, heating may be performed in the range of 200 ° C. to 850 ° C. before diffusion.

Next, as shown in FIG. 1C, the p-type impurity diffusion composition film 2 formed on the surface of the semiconductor substrate 1 is 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, a p-type impurity diffusion layer can be formed on one side of the semiconductor substrate.

FIG. 2 shows a step of applying an n-type impurity diffusion composition to a semiconductor substrate and diffusing n-type impurities from the n-type impurity diffusion composition onto the semiconductor substrate, and the semiconductor substrate using the n-type impurity diffusion composition as a mask. The present invention shows a method of forming an impurity diffusion layer, which comprises a step of applying a p-type impurity to a semiconductor and diffusing it. FIG. 3 describes a method for manufacturing a semiconductor element using the impurity diffusion layer obtained by using the process as shown in FIG. 2 by taking a method for manufacturing a back-bonded solar cell as an example.

First, as shown in FIG. 2A, the n-type impurity diffusion composition film 4 is patterned on the semiconductor substrate 1.

Examples of the method for forming the n-type impurity diffusion composition film 4 include 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 n-type impurity diffusion composition by these methods, the n-type impurity diffusion composition is dried in a hot plate, oven, etc. at 50 to 200 ° C. for 30 seconds to 30 minutes to diffuse the n-type impurities. The composition film 4 is preferable. The film thickness of the obtained n-type impurity diffusion composition film 4 is preferably 200 nm or more in consideration of masking property against p-type impurities, and preferably 5 μm or less from the viewpoint of crack resistance.

Next, as shown in FIG. 2B, the n-type impurities in the n-type impurity diffusion composition film 4 are diffused into the semiconductor substrate 1 to form the n-type impurity diffusion layer 5. As a method for diffusing n-type 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 the concentration of n-type impurities and the diffusion depth of n-type impurities in the obtained n-type impurity diffusion layer. For example, an n-type 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.

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, heating may be performed in the range of 200 ° C. to 850 ° C. before diffusion.

After the n-type impurity is diffused, the n-type impurity diffusion composition film 4 is heated as necessary, and then, as shown in FIG. 2C, the n-type impurity diffusion composition film 4 is used as a mask to p. Apply the type impurity diffusion composition. In this case, as shown in FIG. 2C, the p-type impurity diffusion composition film 2 may be formed on the entire surface, or may be formed only on the portion where the n-type impurity diffusion composition film 4 is not present. .. As shown in FIG. 2C, when the p-type impurity diffusion composition film 2 is formed on the entire surface, a part of the p-type impurity diffusion composition film 2 overlaps with the n-type impurity diffusion composition film 4. However, there is no particular problem.

Examples of the method for applying the p-type impurity diffusion composition 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 p-type impurity diffusion composition by these methods, the applied p-type impurity diffusion composition is dried in a hot plate, oven, etc. at 50 to 200 ° C. for 30 seconds to 30 minutes to diffuse the p-type impurities. The composition film 2 is preferable. The film thickness of the obtained p-type impurity diffusion composition film 2 is preferably 100 nm or more from the viewpoint of diffusivity of p-type impurities, and preferably 3 μm or less from the viewpoint of the residue after etching.

Next, as shown in FIG. 2D, the p-type impurity diffusion composition is diffused from the p-type impurity diffusion composition film 2 onto the semiconductor substrate 1 using the heated n-type impurity diffusion composition film 4 as a mask layer. , P-type impurity diffusion layer 3 is formed. As a method for diffusing p-type impurities onto a semiconductor substrate, a known heat diffusion method can be used, and for example, methods such as electric heating, infrared heating, laser heating, and 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 the diffusion concentration of p-type impurities and the diffusion depth of p-type impurities in the obtained p-type impurity layer. For example, a p-type diffusion layer having ^{a surface impurity concentration of 10 19} to 10 ²¹ can be formed by heating and diffusing at 800 ° C. or higher and 1200 ° C. or lower for 1 to 120 minutes.

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, heating may be performed in the range of 200 ° C. to 850 ° C. before diffusion.

Next, as shown in FIG. 2E, the n-type impurity diffusion composition film 4 and the p-type impurity diffusion composition film 2 formed on the surface of the semiconductor substrate 1 are removed by a known etching method. The material used for etching is not particularly limited, but for example, an etching component containing at least one of hydrogen fluoride, ammonium, phosphoric acid, sulfuric acid, and nitric acid, and other components containing water, an organic solvent, or the like. preferable. Through the above steps, n-type and p-type impurity diffusion layers can be formed on the semiconductor substrate. By adopting such a process, the process can be simplified as compared with the conventional method.

Here, an example in which the p-type impurity diffusion composition is applied / diffused after the n-type impurity diffusion composition is applied / diffused, but the n-type impurity diffusion composition is applied / diffused after the p-type impurity diffusion composition is applied / diffused. It is also possible to apply and diffuse the diffusion composition.

Subsequently, with reference to FIG. 3, the method for manufacturing the semiconductor element of the present invention will be described by taking a back surface bonded solar cell as an example. First, as shown in FIG. 3 (f), the n-type impurity diffusion layer 5 and the p-type impurity diffusion layer 3 of the semiconductor substrate 9 having the n-type impurity diffusion layer 5 and the p-type impurity diffusion layer 3 formed on one side are formed. A protective film 6 is formed on the entire surface of the surface. The surface on which the n-type impurity diffusion layer 5 and the p-type impurity diffusion layer 3 are formed may be referred to as a back surface. Next, as shown in FIG. 3 (g), the protective film 6 is patterned by an etching method or the like to form the protective film opening 6a. Further, as shown in FIG. 3H, the n-type contact electrode 8 and the p-type contact electrode are heated by applying a pattern of the electrode paste to the region including the opening 6a by a stripe coating method, a screen printing method, or the like. 7 is formed. As a result, the back surface bonded type solar cell 10 is obtained.

Further, another method for forming the impurity diffusion layer using the p-type impurity diffusion composition of the present invention will be described with reference to FIG. FIG. 4 shows a step of forming a pattern using an n-type impurity diffusion composition, a step of applying a p-type impurity diffusion composition using the n-type impurity diffusion composition as a mask, and a step of applying the n-type impurity diffusion composition and the n-type impurity diffusion composition. The present invention shows a method of forming an impurity diffusion layer including a step of diffusing n-type and p-type impurities into the semiconductor substrate from a p-type impurity diffusion composition.

First, as shown in FIG. 4A, the n-type impurity diffusion composition film 4 is patterned on the semiconductor substrate 1. Next, after heating the n-type impurity diffusion composition 4 as necessary, as shown in FIG. 4B, the p-type impurity diffusion composition film 2 is formed using the n-type impurity diffusion composition film 4 as a mask. Form. Subsequently, as shown in FIG. 4C, the n-type impurities in the n-type impurity diffusion composition film 4 and the p-type impurities in the p-type impurity diffusion composition film 2 are simultaneously diffused into the semiconductor substrate 1. , N-type impurity diffusion layer 5 and p-type impurity diffusion layer 3 are formed. Examples of the method for applying the n-type and p-type impurity diffusion compositions, the heating method, and the diffusion method include the same methods as in the description based on FIG.

Next, as shown in FIG. 4D, the n-type impurity diffusion composition film 4 and the p-type impurity diffusion composition film 2 formed on the surface of the semiconductor substrate 1 are removed by a known etching method. Through the above steps, n-type and p-type impurity diffusion layers can be formed on one side of the semiconductor substrate. By adopting such a process, the process can be further simplified as compared with the conventional method.

Further, another method for forming the impurity diffusion layer using the p-type impurity diffusion composition of the present invention will be described with reference to FIG.

As shown in FIG. 5A, the p-type impurity diffusion composition film 2 of the present invention is formed on the semiconductor substrate 1. After heating the p-type impurity diffusion composition film 2 as needed, the surface of the semiconductor substrate 1 opposite to the surface on which the p-type impurity diffusion composition film 2 is formed, as shown in FIG. 5 (b). The n-type impurity diffusion composition film 4 is formed on the surface.

Next, as shown in FIG. 5C, the p-type impurities from the p-type impurity diffusion composition film 2 and the n-type impurities from the n-type impurity diffusion composition film 4 are simultaneously diffused into the semiconductor substrate 1. The p-type impurity diffusion layer 3 and the n-type impurity diffusion layer 5 are formed. Examples of the method for applying the n-type and p-type impurity diffusion compositions, the heating method, and the diffusion method include the same methods as in the description based on FIG.

Next, as shown in FIG. 5D, the p-type impurity diffusion composition film 2 and the n-type impurity diffusion composition film 4 formed on the surface of the semiconductor substrate 1 are removed by a known etching method. Through the above steps, n-type and p-type impurity diffusion layers can be formed on the semiconductor substrate. By adopting such a process, the process can be simplified as compared with the conventional method.

Here, an example in which the n-type impurity diffusion composition is applied after the p-type impurity diffusion composition is applied, but the p-type impurity diffusion composition is applied after the n-type impurity diffusion composition is applied. Is also possible.

Further, another method for forming the impurity diffusion layer using the p-type impurity diffusion composition of the present invention will be described with reference to FIG.

As shown in FIG. 6A, the p-type impurity diffusion composition film 2 of the present invention is formed on the semiconductor substrate 1.

Next, as shown in FIG. 6B, the surfaces on which the p-type impurity diffusion composition film 2 is formed are facing each other with a set of two semiconductor substrates on which the p-type impurity diffusion composition film 2 is formed. Arrange them so that they match. The distance between the facing surfaces is preferably 5 mm or less, more preferably in contact.

Next, as shown in FIG. 6C, the p-type impurities are diffused from the p-type impurity diffusion composition film 2 into the semiconductor substrate 1 to form the p-type impurity diffusion layer 3. Examples of the method for applying the p-type impurity diffusion composition, the method for heating, and the method for diffusing the p-type impurity diffusion composition include the same methods as in the description based on FIG.

Next, as shown in FIG. 6D, the semiconductor substrate is in an atmosphere having a gas containing n-type impurities continuously and continuously while the p-type impurity diffusion layers 3 are facing each other. 1 is heated to form an n-type impurity diffusion layer 5 on the surface of the semiconductor substrate 1 on the side where the p-type impurity diffusion composition film 2 is not formed.

At this time, before introducing the gas containing n-type impurities, the semiconductor substrate 1 may be heated in an atmosphere containing oxygen to form an oxide film on the semiconductor substrate 1.

Next, as shown in FIG. 6E, the p-type impurity diffusion composition film 2 formed on the surface of the semiconductor substrate 1 by a known etching method, and the n-type impurity diffusion layer (if necessary). The oxide film remaining in 5 is removed. Through the above steps, n-type and p-type impurity diffusion layers can be formed on the semiconductor substrate. By adopting such a process, the process can be simplified as compared with the conventional method.

The present invention is not limited to the above-described embodiment, and various modifications such as design changes can be made based on the knowledge of those skilled in the art, and the embodiment to which such modifications are added is also the present invention. It is included in the scope of the invention.

The p-type impurity diffusion composition of the present invention is used for photovoltaic devices such as solar cells and semiconductor devices that form an impurity diffusion region on the semiconductor surface, for example, transistor arrays, diode arrays, photodiode arrays, and transducers. Can also be deployed.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Of the compounds used, those using abbreviations are shown below. (Regarding the solvent, the boiling point of the solvent is shown in parentheses)
PVA: Polyvinyl alcohol (manufactured by Japan Vam & Poval Co., Ltd., JP-03)
GBL: γ-Butyrolactone (204 ° C)
PGME: Propylene glycol monomethyl ether (120 ° C)
EtOH: Ethanol (78 ° C)
1-BuOH: 1-butanol (118 ° C)
DEG: Diethylene glycol (245 ° C)
MMB: 3-Methoxy-3-methyl-1-butanol (174 ° C)
DAA: Diacetone alcohol (169 ° C)
BYK333: Silicone surfactant (manufactured by Big Chemie Japan Co., Ltd.)
F444: Fluorine-based surfactant (manufactured by Dainippon Ink and Chemicals Co., Ltd.).

<Evaluation method>
(1) Solution Viscosity and Storage Stability Using a rotary viscometer TVE-25L (E-type digital viscometer) manufactured by Toki Sangyo Co., Ltd., the viscosity was measured at a liquid temperature of 25 ° C. and a rotation speed of 20 rpm.

Here, the viscosity immediately after the production of the p-type impurity diffusion composition, the viscosity after storage at 25 ° C. for 30 days after preparation, and the viscosity after storage at 3 ° C. for 30 days are measured, and the viscosity increase rate is 20% or less. Passed, those exceeding 20% were rejected.

(2) Uniform film thickness of coating film A 6-inch silicon wafer (manufactured by Electronics End Materials Corporation) was immersed in a 1% hydrofluoric acid aqueous solution for 1 minute, washed with water, air blown, and then hot-plate at 140 ° C., 5 Processed for minutes.

Then, the p-type impurity diffusion composition was applied to the silicon wafer by a spin coating method so that the film thickness of the coating film was 1 μm. After coating, the silicon wafer was heated at 140 ° C. for 5 minutes.

The heated wafers were measured at 15 points at equal intervals in the diameter direction, and those having a (maximum value-minimum value) value of 0.3 μm or less were accepted, and those exceeding 0.3 μm were rejected.

(3) Sheet resistance value uniformity (impurity diffusion concentration uniformity)
A 6-inch square textured n-type silicon wafer (manufactured by Electronics End Materials Corporation, surface resistance 200Ω □) is immersed in a 1% hydrofluoric acid aqueous solution for 1 minute, washed with water, air blown, and then hot-plate at 140 ° C. for 5 Heated for minutes.

Then, the p-type impurity diffusion composition was applied to the silicon wafer by a spin coating method so that the film thickness of the coating film was about 500 nm. After coating, the silicon wafer was heated at 140 ° C. for 5 minutes.

Subsequently, each silicon wafer was placed in an electric furnace and maintained at 950 ° C. for 30 minutes in an atmosphere of nitrogen: oxygen = 99: 1 (volume ratio) to thermally diffuse impurities. After thermal diffusion, each silicon wafer was immersed in a 5 wt% hydrofluoric acid aqueous solution at 23 ° C. for 1 minute to peel off the cured diffuser. For the silicon wafer after peeling, p / n judgment is made using a p / n judgment machine, and the surface resistance is measured in the direction etc. using a four-probe type surface resistance measuring device RT-70V (manufactured by Napson Corporation). When 15 points are measured at intervals and the average value, maximum value, and minimum value are A, B, and C, respectively, the value of (BC) / A × 100 (%) is less than 25%. Those with 25% or more were rejected. The evaluation was carried out immediately after preparation of the composition and after storage at 25 ° C. for 30 days after preparation.

(4) Evaluation of organic residue A 6-inch silicon wafer (manufactured by Electronics End Materials Corporation) was cut into 3 cm x 3 cm, immersed in a 1% hydrofluoric acid aqueous solution for 1 minute, washed with water, air blown, and then heated to 140 ° C. on a hot plate. Treated for 5 minutes.

Then, the p-type impurity diffusion composition was applied to the silicon wafer by a spin coating method so that the film thickness of the coating film was about 2 μm. After coating, the silicon wafer was heated at 140 ° C. for 5 minutes.

Subsequently, each silicon wafer was placed in an electric furnace and maintained at 950 ° C. for 30 minutes in an atmosphere of nitrogen: oxygen = 99: 1 (volume ratio) to thermally diffuse impurities.

Each silicon wafer after thermal diffusion was immersed in a 5 mass% hydrofluoric acid aqueous solution at 23 ° C. for 1 minute to peel off the composition. After peeling, the silicon wafer was immersed in pure water for cleaning, and the presence or absence of residue was visually observed on the surface. Surface deposits can be visually confirmed after 1 minute of immersion and cannot be removed by rubbing with a waste cloth, but those that can be removed by rubbing with a waste cloth after further 5 minutes of immersion are D, and surface deposits are visually confirmed after 1 minute of immersion. Those that can be confirmed but can be removed by rubbing with a waste cloth are C, those that exceed 30 seconds and the surface deposits cannot be visually confirmed within 1 minute, those that cannot be visually confirmed within 30 seconds, those that cannot be visually confirmed within 30 seconds. Was A. From the viewpoint of suppressing organic residues, it can be judged that the result is more preferable in the order of D <C <B <A.

(5) Evaluation of Na content The composition is precisely weighed in a "Teflon" (registered trademark) decomposition container, decomposed with sulfuric acid-nitric acid-hydrofluoric acid-hydrogen peroxide solution, and then dissolved in dilute nitric acid. It was prepared as a constant solution. The obtained solution was measured by ICP mass spectrometry (ELAN DRC II manufactured by PerkinElmer).

Formulation example 1
Put 4.21 g of PVA (manufactured by Japan Vam & Poval Co., Ltd., JP-03) and 14.2 g of water in a 150 mL three-necked flask, raise the temperature to 80 ° C. with stirring, stir for 1 hour, and then 1 80.3 g of −BuOH (manufactured by Tokyo Kasei Co., Ltd.) and 1.29 g of boric acid (manufactured by Fuji Yakuhin Kogyo Co., Ltd.) were added, and the mixture was stirred at 80 ° C. for 1 hour. After cooling to 40 ° C., 0.05 g of a silicone-based surfactant BYK333 (manufactured by Big Chemie Japan Co., Ltd.) was added, and the mixture was stirred for 30 minutes. This mixed solution was treated with an ion exchange treatment A and then filtered through a 20 μm filter to obtain a p-type impurity diffusion composition A. The viscosity of the obtained composition was 18 mPa · s and the pH was 5.0.

Formulation Examples 2 to 23
Each composition shown in Table 1 was mixed, ion-exchanged, and filtered through a 20 μm filter in the same manner as in Formulation Example 1 to obtain p-type impurity diffusion compositions B to X. However, in Formulation Examples 16, 21, 22, and 23, the ion exchange treatment was not performed. Further, in Formulation Examples 15, 16, 21 and 22, an organic base or an acid was further added.

Here, the ion exchange treatment was carried out by either the following method (A) or (B).
(A) A mixed solution containing each component is passed through a column packed with a cation exchange resin (Amberlist 15JS-HG-DRY manufactured by Organo Corporation).
(B) The mixed solution containing each component is passed through a column packed with an exchange resin (manufactured by Organo Corporation, Amberlist MSPS2-1-DRY) containing a mixture of cations and anions.

Examples 1-16, Comparative Examples 1-7
The evaluation results are shown in Table 2.

In the table, "(d) / (c)" († 1) means "(d) surfactant / mass ratio of (c) Group 13 element compound" to "(c) / (a)" ( † 2) represents "(c) Group 13 element compound / (a) mass ratio of resin".

1 Semiconductor substrate 2 p-type impurity diffusion composition film 3 p-type impurity diffusion layer 4 n-type impurity diffusion composition film 5 n-type impurity diffusion layer 6 protective film 6a protective film opening 7 p-type contact electrode 8 n-type contact electrode 9 single-sided Semiconductor substrate 10 on which an n-type impurity diffusion layer and a p-type impurity diffusion layer are formed.

Claims (15)

(A) At least one resin selected from polyvinyl alcohol and polyethylene oxide,
A p-type impurity diffusion composition containing (b) a solvent and (c) a compound containing a Group 13 element, wherein the pH of the composition is 4 to 6.5, and (b) the solvent is (b-). 1) It contains an organic solvent having a boiling point of 110 ° C. or higher and 210 ° C. or lower and (b-2) water, and the amount of (b-2) water is 10 to 50% by mass in the (b) solvent. P-type impurity diffusion composition. (B-1) The boiling point of the organic solvent is 165 ° C. or higher and 180 ° C. or lower, and (b-2) the amount of water is (b) 20 to 35% by mass in the solvent. The p-type impurity diffusion composition according to. (B-1) The p-type impurity diffusion composition according to claim 2, wherein the organic solvent is 3-methoxy-3-methyl-1-butanol. The p-type impurity diffusion composition according to any one of claims 1 to 3, further comprising (d) a surfactant. The p-type impurity diffusion composition according to claim 4, wherein the surfactant is a silicone-based and / or acrylic-based compound. (D) The p-type impurity diffusion composition according to claim 4 or 5, wherein the mass ratio of the surfactant / (c) Group 13 element compound is 0.03 to 0.1. (C) The p-type impurity diffusion composition according to any one of claims 1 to 6, wherein the mass ratio of the Group 13 element compound / (a) resin is 0.25 to 0.45. The p-type impurity diffusion composition according to any one of claims 1 to 7, further comprising a tertiary amine. The method for producing a p-type impurity diffusion composition according to any one of claims 1 to 8, wherein the entire composition containing the components (a) to (c) or the components (a) to (c) A method for producing a p-type impurity diffusion composition, which comprises a step of performing an ion exchange treatment of at least one of them with an ion exchange resin. The method for producing a p-type impurity diffusion composition according to claim 9, wherein the ion exchange treatment is performed by combining a cation exchange resin and an anion exchange resin. A step of applying the p-type impurity diffusion composition according to any one of claims 1 to 8 to a semiconductor substrate to form a p-type impurity diffusion composition film, and a step of forming a p-type impurity diffusion composition film from the p-type impurity diffusion composition film. A method for manufacturing a semiconductor device, which comprises a step of diffusing the semiconductor substrate to form a p-type impurity diffusion layer on the semiconductor substrate. After the n-type impurity diffusion composition is partially applied to the semiconductor substrate to form the n-type impurity diffusion composition film, the portion where the n-type impurity diffusion composition is not applied by using the n-type impurity diffusion composition film as a mask. A method for manufacturing a semiconductor device, comprising the step of applying the p-type impurity diffusion composition according to any one of claims 1 to 8 to form a p-type impurity diffusion composition film. The step of applying the p-type impurity diffusion composition according to any one of claims 1 to 8 to form a p-type impurity diffusion composition film on one surface of a semiconductor substrate, and on the other surface of the semiconductor substrate. By applying the n-type impurity diffusion composition to form the n-type impurity diffusion composition film and heating the p-type impurity diffusion composition film and the n-type impurity diffusion composition film at the same time, the p-type impurity diffusion composition film is heated at the same time. A method for manufacturing a semiconductor device, which comprises a step of forming a diffusion layer and an n-type impurity diffusion layer. A step of applying the p-type impurity diffusion composition according to any one of claims 1 to 8 to form a p-type impurity diffusion composition film on one surface of a semiconductor substrate, and a step of forming a p-type impurity diffusion composition film. The steps of arranging the semiconductor substrates so that the surfaces on which the p-type impurity diffusion composition film is formed in a set of two are facing each other, and the p-type impurities are removed from the p-type impurity diffusion composition film. The step of forming a p-type impurity diffusion layer on the semiconductor substrate by diffusing it on the semiconductor substrate, and heating the semiconductor substrate in an atmosphere having a gas containing n-type impurities continuously as it is, the other side of the semiconductor substrate. A method for manufacturing a semiconductor device, which comprises a step of diffusing an n-type impurity on the surface of the semiconductor device to form an n-type impurity diffusion layer. A solar cell including a semiconductor device obtained by the manufacturing method according to any one of claims 11 to 14.

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