JP2014090020A - Composition for forming barrier layer, semiconductor substrate with barrier layer, method for manufacturing substrate for solar cell, and method for manufacturing solar cell element - Google Patents

Abstract

Provided are a barrier layer forming composition, a semiconductor substrate with a barrier layer, a method for producing a solar cell substrate, and a method for producing a solar cell element, which can sufficiently prevent diffusion of a donor element or an acceptor element.
An alkaline earth metal or a metal compound containing an alkali metal and a dispersion medium, and the total content of iron, manganese, tungsten, gold, chromium, and nickel is 5% by mass or less. A composition for forming a barrier layer.
[Selection figure] None

Description

  The present invention relates to a barrier layer forming composition, a semiconductor substrate with a barrier layer, a method for manufacturing a solar cell substrate, and a method for manufacturing a solar cell element.

The manufacturing process of the conventional silicon solar cell element is demonstrated. First, a p-type silicon substrate having a texture structure formed on the light-receiving surface is prepared so as to promote the light confinement effect and increase the efficiency, and then in a mixed gas atmosphere of phosphorus oxychloride (POCl ₃ ), nitrogen and oxygen, 800 An n-type diffusion layer is uniformly formed by performing several tens of minutes of processing at a temperature of from 900C to 900C. Subsequently, an electrode paste such as Ag was applied to the light receiving surface, and an electrode paste such as aluminum was applied to the back surface and baked to obtain a solar cell element.

However, since sunlight does not enter directly under the electrode on the light receiving surface side, power is not generated in that portion. Therefore, a back electrode type solar cell has been developed that has no electrode on the light receiving surface, an n type diffusion layer and a p ⁺ type diffusion layer on the back surface, and electrodes on the respective diffusion layers (for example, Patent Document 1). reference).

A method of forming such a back electrode type solar cell will be described. A barrier layer is formed on the entire light receiving surface and back surface of the n-type silicon substrate. Here, the barrier layer has a function of suppressing the diffusion of impurities into the silicon substrate. Next, a part of the barrier layer on the back surface of the silicon substrate is removed to form an opening. Then, when p-type impurities are diffused from the opening of the barrier layer to the back surface of the silicon substrate, a p ⁺ -type diffusion layer is formed in a region corresponding to the opening. Next, after all the barrier layer on the back surface of the silicon substrate is removed, a barrier layer is formed again on the entire back surface of the silicon substrate. Then, a part of the barrier layer in a region different from the region where the p ⁺ -type diffusion layer is formed is removed to form an opening, and n-type impurities are diffused from the opening to the back surface of the silicon substrate. ^{A +} type diffusion layer is formed. Subsequently, by removing all the barrier layer on the back surface of the silicon substrate, a p ⁺ -type diffusion layer and an n ⁺ -type diffusion layer are formed on the back surface. Furthermore, a back electrode type solar cell is completed by forming a texture structure, an antireflection film, a passivation film, an electrode, and the like.

As the barrier layer, a method using an oxide film formed on the substrate surface by a thermal oxidation method has been proposed (see, for example, Patent Document 2). On the other hand, a method for forming a barrier layer using a masking paste containing a SiO ₂ precursor has also been proposed (see, for example, Patent Document 3).

JP 2011-507246 A JP 2002-329880 A JP 2007-49079 A

However, the method of generating an oxide film on the substrate surface by the thermal oxidation method described in Patent Document 2 described above has a problem in that the manufacturing cost is high because the throughput is long.
Moreover, in the method using the masking paste containing the SiO ₂ precursor described in Patent Document 3, it is intended to physically prevent the diffusion of the donor element or the acceptor element, and the barrier layer made of SiO ₂ is dense. Since it is difficult to form a film and pinholes are easily formed, it has been difficult to sufficiently prevent diffusion of the dopant into the substrate. Further, the conventional masking paste has a tendency that the lifetime of carriers in the formed solar cell substrate is lowered.

  Therefore, the present invention has been made in view of the above-described conventional problems, and sufficiently prevents the diffusion of a donor element or an acceptor element into a semiconductor substrate without reducing the lifetime of carriers in the solar cell substrate. It is an object of the present invention to provide a barrier layer-forming composition, a semiconductor substrate with a barrier layer, a method for manufacturing a solar cell substrate, and a method for manufacturing a solar cell element.

Specific means for solving the above problems are as follows.
<1> containing an alkaline earth metal or a metal compound containing an alkali metal, and a dispersion medium,
The composition for barrier layer formation whose total content rate of iron, manganese, tungsten, gold | metal | money, chromium, and nickel is 5 mass% or less.

<2> The composition for forming a barrier layer according to <1>, wherein the total content of the iron, manganese, tungsten, gold, chromium, and nickel is 1% by mass or less.

<3> The metal compound containing the alkaline earth metal or alkali metal is selected from the group consisting of magnesium, calcium, sodium, potassium, lithium, rubidium, cesium, beryllium, strontium, barium, and radium as the metal element. The composition for forming a barrier layer according to the above <1> or <2>, comprising one or more of the above.

<4> The alkaline earth metal or the metal compound containing an alkali metal is magnesium oxide, calcium oxide, potassium oxide, magnesium carbonate, calcium carbonate, magnesium sulfate, calcium sulfate, calcium nitrate, magnesium hydroxide, and calcium hydroxide. The composition for forming a barrier layer according to any one of <1> to <3>, comprising at least one selected from the group consisting of:

<5> Any of the above <1> to <4>, wherein the alkaline earth metal or the metal compound containing an alkali metal includes one or more selected from the group consisting of calcium carbonate, calcium oxide, and magnesium carbonate 2. The composition for forming a barrier layer according to item 1.

<6> The total content of the alkaline earth metal or the metal compound containing an alkali metal is 0.1% by mass or more and less than 80% by mass, according to any one of <1> to <5>. A composition for forming a barrier layer.

<7> Any one of the above <1> to <6>, wherein the dispersion medium contains one or more selected from the group consisting of water, alcohol solvents, glycol monoether solvents, and terpene solvents. A composition for forming a barrier layer as described in 1. above.

<8> The composition for forming a barrier layer according to any one of <1> to <7>, which is used for forming a mask for partially forming a diffusion layer on a semiconductor substrate.

The barrier layer which has a <9> semiconductor substrate and the barrier layer which is a dry body of the composition for barrier layer formation of any one of said <1>-<7> provided on the said semiconductor substrate. With a semiconductor substrate.

<10> A step of applying the barrier layer forming composition according to any one of <1> to <7> above in a pattern on a semiconductor substrate to form a barrier layer;
Doping a donor element or an acceptor element from a portion where the barrier layer is not formed on the semiconductor substrate, and partially forming a diffusion layer in the semiconductor substrate;
The manufacturing method of the board | substrate for solar cells containing.

<11> The method for producing a solar cell substrate according to <10>, wherein the method for applying the composition for forming a barrier layer is a printing method or an inkjet method.

<12> A method for producing a solar cell element, comprising a step of forming an electrode on a diffusion layer of a solar cell substrate obtained by the production method according to <10> or <11>.

  ADVANTAGE OF THE INVENTION According to this invention, the composition for barrier layer formation which can fully prevent the spreading | diffusion to a semiconductor substrate of a donor element or an acceptor element without reducing the lifetime of the carrier in a solar cell substrate, with a barrier layer A semiconductor substrate, a method for manufacturing a solar cell substrate, and a method for manufacturing a solar cell element can be provided.

It is sectional drawing which shows notionally an example of the manufacturing process of the board | substrate for solar cells of this invention, and a solar cell element.

  First, the barrier layer-forming composition of the present invention will be described, the semiconductor substrate with a barrier layer obtained thereby will be described, and then a solar cell substrate manufacturing method and solar cell element using the barrier layer-forming composition will be described. A manufacturing method will be described. In this specification, the term “process” is not limited to an independent process, and even if it cannot be clearly distinguished from other processes, the term “process” is used if the intended action of the process is achieved. included. In the present specification, “to” indicates a range including the numerical values described before and after the values as a minimum value and a maximum value, respectively. Further, in this specification, the amount of each component in the composition is the sum of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. Means quantity.

<Barrier layer forming composition>
The composition for forming a barrier layer of the present invention contains an alkaline earth metal or a metal compound containing an alkali metal (hereinafter also referred to as “specific compound”) and a dispersion medium. The composition for forming a barrier layer of the present invention inhibits diffusion of a donor element or an acceptor element, which is a dopant, into a semiconductor substrate. Therefore, by forming a barrier layer using the barrier layer forming composition of the present invention in a region where the donor element or the acceptor element is not desired to be diffused in the semiconductor substrate, the donor element and the acceptor element are diffused in the region. It can be sufficiently prevented. Therefore, a doping region (diffusion layer region) can be selectively formed in the semiconductor substrate. The reason for this can be considered as follows.

When a specific compound is contained in the composition for forming a barrier layer and this doping composition is applied to a semiconductor substrate and then a doping compound is applied, a reaction occurs between the specific compound and the doping compound. Since this reaction is more reactive than the reaction between the doping compound and the semiconductor substrate, it is considered that the diffusion of the donor element or the acceptor element into the semiconductor substrate is hindered.
In general, as a doping compound containing a donor element or an acceptor element, phosphorus oxide, boron oxide, phosphorus oxychloride, or the like is used, and these are all acidic compounds (or compounds that react with water to show acidity). ). Therefore, in particular, the specific compound is preferably a basic compound. The specific compound of the basic compound undergoes an acid-base reaction with the doping compound, and this acid-base reaction has high reactivity, and thus more effectively inhibits the donor element or the acceptor element from diffusing into the semiconductor substrate.

In addition, since the alkaline earth metal or the metal compound containing the alkali metal is stable even at a high temperature (for example, 500 ° C. or higher), the effect of the present invention is sufficiently obtained when the donor element or the acceptor element is thermally diffused in the semiconductor substrate. Can be demonstrated.
In addition, an alkaline earth metal or a metal compound containing an alkali metal does not act as a carrier recombination center in the semiconductor substrate when dissolved in the semiconductor substrate, thereby suppressing a problem of reducing the conversion efficiency of the semiconductor substrate. be able to.

  And the composition for barrier layer formation of this invention is 5 mass% or less in total content of iron, manganese, tungsten, gold | metal | money, chromium, and nickel. Thereby, the fall of the lifetime of the carrier in a solar cell board | substrate is suppressed.

(Alkaline earth metal or metal compound containing alkali metal)
The composition for forming a barrier layer of the present invention contains an alkaline earth metal or a metal compound containing an alkali metal. By containing an alkaline earth metal or a metal compound containing an alkali metal, it is possible to inhibit the donor element or the acceptor element from diffusing into the semiconductor substrate.
The alkaline earth metal or the metal compound containing the alkali metal may be liquid or solid at room temperature (about 20 ° C.). From the viewpoint that it is necessary to be chemically stable even at a high temperature in order to maintain a sufficient barrier layer performance even at a high temperature, it is preferably a solid at a high temperature (for example, 500 ° C. or higher) at which heat is diffused. Here, for example, the alkaline earth metal or the metal compound containing an alkali metal includes an alkaline earth metal or a metal oxide containing an alkali metal, an alkaline earth metal or a metal salt containing an alkali metal.

The alkaline earth metal or the metal compound containing an alkali metal is not particularly limited, and is preferably a material that changes to a basic compound at a high temperature of 700 ° C. or higher at which a donor element or an acceptor element is thermally diffused. From the viewpoint of exhibiting stronger basicity, the metal compound contains at least one selected from the group consisting of magnesium, calcium, sodium, potassium, lithium, rubidium, cesium, beryllium, strontium, barium and radium as a metal element. It is more preferable that it contains at least one selected from the group consisting of magnesium, calcium, barium, potassium and sodium, and more preferably contains at least one selected from the group consisting of magnesium, calcium and potassium. More preferably, from the viewpoint of low toxicity and availability, it is more preferable to contain one or more selected from the group consisting of magnesium and calcium.
And from the viewpoint of chemical stability, from the group consisting of metal oxides, metal carbonates, metal nitrates, metal sulfates and metal hydroxides containing one or more selected from the group consisting of these metal elements It is preferably one or more selected, more preferably one or more selected from the group consisting of metal oxides, metal carbonates and metal hydroxides.

In particular, metal oxides such as sodium oxide, potassium oxide, lithium oxide, calcium oxide, magnesium oxide, rubidium oxide, cesium oxide, beryllium oxide, strontium oxide, barium oxide, radium oxide, and complex oxides thereof; sodium hydroxide, Metal hydroxides such as potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, beryllium hydroxide, strontium hydroxide, barium hydroxide, radium hydroxide; sodium carbonate, carbonic acid Metal carbonates such as potassium, lithium carbonate, calcium carbonate, magnesium carbonate, rubidium carbonate, cesium carbonate, beryllium carbonate, strontium carbonate, barium carbonate, radium carbonate; sodium nitrate, potassium nitrate, lithium nitrate, calcium nitrate Metal nitrates such as magnesium nitrate, rubidium nitrate, cesium nitrate, beryllium nitrate, strontium nitrate, barium nitrate, radium nitrate; sodium sulfate, potassium sulfate, lithium sulfate, calcium sulfate, magnesium sulfate, rubidium sulfate, cesium sulfate, beryllium sulfate, It is preferable to use metal sulfates such as strontium sulfate, barium sulfate, and radium sulfate.
More preferably, at least one selected from the group consisting of the metal oxides, complex oxides thereof, metal hydroxides, and metal carbonates is used.

  Among these, from the viewpoint of low toxicity and easy availability, sodium carbonate, sodium oxide, potassium carbonate, potassium oxide, calcium carbonate, calcium hydroxide, calcium oxide, magnesium carbonate, magnesium hydroxide, magnesium sulfate, calcium sulfate, It is preferable to use at least one selected from calcium nitrate and magnesium oxide, and magnesium oxide, calcium oxide, magnesium carbonate, calcium carbonate, magnesium sulfate, calcium sulfate, calcium nitrate, potassium oxide, magnesium hydroxide and calcium hydroxide It is more preferable to use at least one selected from the group consisting of calcium carbonate, calcium oxide, potassium oxide, calcium hydroxide, magnesium carbonate and magnesium oxide. More preferably the use of the above species, calcium carbonate, calcium oxide and particularly preferred to use at least one selected from the group consisting of magnesium carbonate, it is most preferable to use calcium carbonate.

When the alkaline earth metal or the metal compound containing the alkali metal is solid at room temperature and has a particle shape, the particle diameter of the particles is preferably 30 μm or less, and 0.01 μm to 30 μm. More preferably, it is more preferably 0.02 μm to 10 μm, and particularly preferably 0.03 μm to 5 μm.
When the particle diameter is 30 μm or less, the donor element or the acceptor element can be uniformly diffused (doped) by the coating portion on the semiconductor substrate. Moreover, it is easy to disperse | distribute the metal compound containing an alkaline-earth metal or an alkali metal uniformly in the composition for barrier layer formation as it is 0.01 micrometer or more. Moreover, the alkaline earth metal or the metal compound containing an alkali metal may be dissolved in the dispersion medium.
The particle diameter represents a volume average particle diameter, and can be measured with a laser scattering diffraction particle size distribution measuring apparatus or the like. The volume average particle diameter can be calculated based on the Mie scattering theory by detecting the relationship between the scattered light intensity and the angle of the laser light applied to the particles. Although there is no restriction | limiting in particular in the dispersion medium at the time of measuring, It is preferable to use the dispersion medium in which the particle | grains made into a measurement object do not melt | dissolve.

  There is no restriction | limiting in particular as a method of obtaining the said particle | grains of 30 micrometers or less, For example, it can obtain by grind | pulverizing. As a grinding method, a dry grinding method and a wet grinding method can be employed. As the dry pulverization method, a jet mill, a vibration mill, a ball mill, or the like can be employed. As the wet pulverization method, a bead mill, a ball mill or the like can be used.

  When impurities resulting from the pulverization apparatus are mixed into the barrier layer forming composition during the pulverization process, the lifetime of the carriers in the semiconductor substrate may be reduced. It is preferable to select a material with little influence. Examples of the material of the container and the like that are preferably used during pulverization include alumina and partially stabilized zirconia. In addition to the pulverization method, a gas phase oxidation method, a hydrolysis method, or the like can be used.

  Further, the particles include particles composed of an alkaline earth metal or a compound other than a metal compound containing an alkali metal (for example, silicon oxide particles) as a carrier, and the surface of the carrier contains an alkaline earth metal or an alkali metal. The metal compound to be coated or dispersed and supported may be used. In this embodiment, it is possible to increase the effective surface area of the alkaline earth metal or the metal compound containing the alkali metal, and there is a possibility that the property of inhibiting the diffusion of the donor element or the acceptor element into the semiconductor substrate may be improved. .

The carrier is preferably a material having a BET specific surface area of 10 m ² / g or more, and examples thereof include particles of inorganic materials such as SiO ₂ , activated carbon, carbon fiber, and zinc oxide.

  The shape of the particles is not particularly limited, and may be any of a substantially spherical shape, a flat shape, a scale shape, a block shape, an oval shape, a plate shape, and a rod shape. The shape of the particles can be confirmed by an electron microscope or the like.

The content of the alkaline earth metal or the metal compound containing the alkali metal in the composition for forming a barrier layer is determined in consideration of the coating property, the diffusibility of the donor element or the acceptor element, and the like. Generally, the content ratio of the alkaline earth metal or the metal compound containing an alkali metal in the barrier layer forming composition is 0.1% by mass or more and 95% by mass or less in the barrier layer forming composition. Is preferably 0.1% by mass or more and 80% by mass or less, more preferably 0.1% by mass or more and 50% by mass or less, and particularly preferably 2% by mass or more and 50% by mass or less. Most preferably, it is 5 mass% or more and 20 mass% or less.
When the content of the alkaline earth metal or the metal compound containing the alkali metal is 0.1% by mass or more, the diffusion of the donor element or the acceptor element into the semiconductor substrate can be sufficiently inhibited. When the content is 95% by mass or less, the dispersibility of the alkaline earth metal or the metal compound containing the alkali metal in the barrier layer forming composition is improved, and the coating property to the substrate is improved.

Further, the total content of the alkaline earth metal and the metal compound containing the alkali metal in all the non-volatile components of the barrier layer forming composition is preferably 5% by mass or more and less than 100% by mass, and 20 or more and 99% by mass. % Or less is more preferable. By being within the above range, a sufficient barrier control effect tends to be obtained.
Here, the non-volatile component refers to a component that does not volatilize when heat-treated at 600 ° C. or higher. The non-volatile component can be obtained by a thermogravimetric analyzer TG, and the total content of the alkaline earth metal and the metal compound containing the alkali metal in the non-volatile component is determined by ICP emission spectroscopy / mass spectrometry (ICP-MS Method) and atomic absorption method.

(Lifetime killer element)
In the composition for forming a barrier layer of the present invention, the total content of lifetime killer elements is 5% by mass or less, preferably 2.5% by mass or less, more preferably 1% by mass or less, and still more preferably. Is 1000 ppm or less, particularly preferably not contained. The term “lifetime killer element” as used herein refers to an impurity that, when mixed in a semiconductor substrate, creates a level in the center of the band and lowers the lifetime of carriers (electrons, holes) in the semiconductor substrate. In the present invention, the lifetime killer element refers to iron (Fe), manganese (Mn), tungsten (W), gold (Au), chromium (Cr), and nickel (Ni).

  The effective lifetime of minority carriers in the semiconductor substrate can be evaluated by measuring by a reflection microwave conductive attenuation method using a device such as WT-2000PVN manufactured by Nippon Semilab.

Here, the effective lifetime τ is expressed by the following equation (A) by the bulk lifetime τ _b inside the semiconductor substrate and the surface lifetime τ _s of the semiconductor substrate surface. When the surface state density on the surface of the semiconductor substrate is small, τ _s increases, and as a result, the effective lifetime τ increases. Further, even if defects such as dangling bonds inside the semiconductor substrate are reduced, the bulk lifetime τ _b is increased and the effective lifetime τ is increased. That is, by measuring the effective lifetime τ, the interface characteristics of the passivation film / semiconductor substrate and the internal characteristics of the semiconductor substrate such as dangling bonds can be evaluated.
1 / τ = 1 / τ _b + 1 / τ _s (A)
Note that the longer the effective lifetime, the slower the recombination rate of minority carriers. Moreover, conversion efficiency improves by comprising a solar cell element using the semiconductor substrate with a long effective lifetime.

  In addition to the lifetime killer elements Fe, Mn, W, Au, Cr, and Ni, Sc, Ti, V, Co, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, The total content of impurities of Hf, Ta, Re, Os, Ir, and Pt is preferably 5% by mass or less, more preferably 2.5% by mass or less in the barrier layer forming composition, The content is more preferably 1% by mass or less, and particularly preferably 1000ppm or less. After applying the barrier layer forming composition having the impurity content in the above range to the semiconductor substrate, when the dopant is diffused into the semiconductor substrate by heating at 800 ° C. or higher, minority carriers in the semiconductor substrate A decrease in effective lifetime is more effectively suppressed.

  In order to achieve such a low lifetime killer element and the content of the impurities, it is preferable to select a material that contains as little as possible the lifetime killer element and the impurities as the raw material of the barrier layer forming composition. Alternatively, the obtained raw material may be used after being washed with ultrapure water or the like.

  The content rate of the lifetime killer element in the composition for forming a barrier layer can be examined using an ICP-MS method or a glow discharge mass spectrometry method.

(Dispersion medium)
The barrier layer forming composition of the present invention contains a dispersion medium. The dispersion medium is a medium in which the alkaline earth metal or the metal compound containing the alkali metal is dispersed or dissolved in the composition. Examples of the dispersion medium include a solvent and water.

Examples of the solvent include 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, Ketone solvents such as propyl ketone, diisobutyl ketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone; diethyl ether, methyl ethyl ether, methyl-n-propyl ether, diisopropyl Ether, tetrahydrofuran, methyltetrahydrofuran, dioxane, dimethyldioxane, 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 glycol methyl ethyl 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 meth Ruethyl 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, tetra Propylene glycol methyl ethyl ether, tetrapropylene glycol methyl ether solvents such as 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-ethylhexyl acetate, 2- (2-acetate) Butoxyethoxy) ethyl, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, nonyl acetate, methyl acetoacetate, ethyl acetoacetate, diethylene glycol methyl ether acetate, diethylene glycol monoethyl acetate , Dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, glycol diacetate, methoxytriglycol 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. Tellurium solvents; acetonitrile, N-methylpyrrolidinone, N-ethylpyrrolidinone, N-propylpyrrolidinone, N-butylpyrrolidinone, N-hexylpyrrolidinone, N-cyclohexylpyrrolidinone, N, N-dimethylformamide, N, N-dimethylacetamide, Aprotic polar solvents such as dimethyl sulfoxide; methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec -Pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, benzyl Alcohol solvents such as alcohol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, isobornylcyclohexanol; ethylene glycol monomethyl ether, ethylene Glycol monoethyl ether (cellosolve), ethylene glycol monophenyl ether, diethylene glycol monome 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 monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono Glycol monoether solvents such as ethyl ether and tripropylene glycol monomethyl ether; Of terpene solvents. These are used singly or in combination of two or more.
Among these, from the viewpoint of applicability to a semiconductor substrate, water, an alcohol solvent, a glycol monoether solvent, or a terpene solvent is preferable as the dispersion medium, and water, alcohol, cellosolve, terpineol, diethylene glycol mono-n. -Butyl ether or diethylene glycol acetate mono-n-butyl ether is preferred, and water, alcohol, terpineol or cellosolve is preferred.

  The content of the dispersion medium in the composition for forming a barrier layer is determined in consideration of applicability and barrier performance of the barrier layer. For example, in the composition for forming a barrier layer, the content of the dispersion medium is 5% by mass or more and 99% by mass or less. Preferably, the content is 20% by mass or more and 95% by mass or less, and more preferably 40% by mass or more and 90% by mass or less.

(Organic binder)
The composition for forming a barrier layer of the present invention may contain an organic binder. By containing the organic binder, the alkaline earth metal or the metal compound containing the alkali metal is bound to each other at a high temperature, and the alkaline earth metal or the metal compound containing the alkali metal is bound to the semiconductor substrate. It becomes easy to make.

Examples of the organic binder include polyvinyl alcohol; polyacrylamide resin; polyvinyl amide resin; polyvinyl pyrrolidone resin; polyethylene oxide resin; polysulfone resin; acrylamide alkyl sulfone resin; cellulose derivatives such as cellulose ether, carboxymethyl cellulose, hydroxyethyl cellulose, and ethyl cellulose; Starch, starch derivative; sodium alginate; xanthan; guar, gua derivative; scleroglucan, scleroglucan derivative; tragacanth, tragacanth derivative; dextrin, dextrin derivative; (meth) acrylic acid resin; alkyl (meth) (Meth) acrylic acid ester resins such as acrylate resins and dimethylaminoethyl (meth) acrylate resins; Tajien resins; styrene resins; and can select these copolymers as appropriate.
Among these, it is preferable that an acrylic acid resin or a cellulose derivative is included from the viewpoint of degradability and prevention of dripping at the time of screen printing. These are used singly or in combination of two or more.

  The molecular weight of the organic binder is not particularly limited, and it is desirable to adjust appropriately in view of the desired viscosity as the barrier layer forming composition. In addition, it is preferable that the content rate in the case of containing an organic binder is 0.5 mass% or more and 30 mass% or less in the composition for barrier layer formation, and it is 3 mass% or more and 25 mass% or less. More preferably, it is 3 mass% or more and 20 mass% or less.

  Further, the mass ratio of the total content of the alkaline earth metal and the metal compound containing the alkali metal to the total content of the organic binder (alkaline earth metal and alkali metal metal compound) / (organic binder) is 99.9. /0.1 to 0.1 / 99.9 is preferable, and 99/1 to 20/80 is more preferable.

  Note that a dispersion medium in which an organic binder is dissolved may be used as the dispersion medium and the organic binder.

(Other ingredients)
The composition for forming a barrier layer comprises a thickener, a wetting agent, a surfactant as other components in addition to an alkaline earth metal or a metal compound containing an alkali metal, a dispersion medium, and an organic binder. In addition, various additives such as inorganic powder and a resin containing a silicon atom may be contained.

  Examples of the surfactant include nonionic surfactants, cationic surfactants, and anionic surfactants. Among these, nonionic surfactants or cationic surfactants are preferred because impurities such as heavy metals are not brought into the semiconductor device. Furthermore, silicon-based surfactants, fluorine-based surfactants, and hydrocarbon-based surfactants are exemplified as nonionic surfactants, and hydrocarbon-based surfactants are rapidly baked upon heating such as diffusion. Is preferred.

  Examples of the hydrocarbon surfactant include an ethylene oxide-propylene oxide block copolymer, an acetylene glycol compound, and the like, and an acetylene glycol compound is more preferable because variation in resistance value of the semiconductor device is further reduced.

  Examples of the inorganic powder include powders such as silicon nitride, silicon oxide, and silicon carbide.

The viscosity of the barrier layer forming composition is not particularly limited. Specifically, the viscosity measured at 25 ° C. with an E-type viscometer at a rotation speed of 0.5 rpm to 5 rpm is preferably 0.5 Pa · s to 400 Pa · s, and 10 Pa · s to 100 Pa · s. It is more preferable that When it is 0.5 Pa · s or more, dripping does not easily occur when it is applied to a semiconductor substrate, and when it is 400 Pa · s or less, a fine coating pattern can be formed.
In addition, the viscosity of the composition for forming a barrier layer can be determined by a rotation method, a stress control method, or a strain control method using a B-type viscometer, an E-type viscometer, a viscoelasticity measuring device, or the like.

  The composition for forming a barrier layer of the present invention uses a blender, a mixer, a mortar, or a rotor containing an alkaline earth metal or a metal compound containing an alkali metal, a dispersion medium, an organic binder, and components added as necessary. Can be obtained by mixing. Moreover, when mixing, you may add a heat | fever as needed. The heating temperature at this time can be 30 degreeC-100 degreeC, for example.

<Semiconductor substrate with barrier layer>
The semiconductor substrate with a barrier layer of the present invention includes a semiconductor substrate and a barrier layer that is a dry body of the composition for forming a barrier layer provided on the semiconductor substrate. The drying conditions of the barrier layer forming composition depend on the content of the dispersion medium in the barrier layer forming composition and are not particularly limited in the present invention. For example, it is dried at a temperature of about 80 ° C. to 300 ° C. for 1 minute to 10 minutes when using a hot plate, and about 10 to 30 minutes when using a dryer or the like.
There is no restriction | limiting in particular in the thickness of a barrier layer, It is preferable that they are 0.1 micrometer-50 micrometers, and it is more preferable that they are 1 micrometer-30 micrometers. The thickness of the barrier layer can be measured by, for example, a high-precision shape measurement system KS-1100 series manufactured by Keyence, and is represented by an average value when measured at four locations.

<Method for Manufacturing Solar Cell Substrate and Solar Cell Element>
The method for manufacturing a solar cell substrate of the present invention includes a step of forming the barrier layer by applying the composition for forming a barrier layer on a semiconductor substrate in a pattern, and the barrier layer on the semiconductor substrate is formed. Forming a diffusion layer partially in the semiconductor substrate by doping a non-existing portion with a donor element or an acceptor element. The barrier layer forming composition is used to form a mask for partially forming a diffusion layer on a semiconductor substrate.
Moreover, the manufacturing method of the solar cell element of this invention includes the process of forming an electrode on the diffusion layer of the board | substrate for solar cells obtained by the said manufacturing method.

  Here, the manufacturing method of the board | substrate for solar cells and the solar cell element using the composition for barrier layer formation of this invention is demonstrated, referring FIG. FIG. 1 is a schematic cross-sectional view conceptually showing an example of a manufacturing process of a solar cell substrate and a solar cell element of the present invention.

In addition, although FIG. 1 demonstrates the board | substrate for solar cell and a solar cell element of a back surface electrode type, the composition for barrier layer formation of this invention is applicable to the board | substrate for solar cells and a solar cell element of any type. Examples of other types other than the back electrode type include a selective emitter type and a double-sided light receiving type solar cell substrate and a solar cell element. In the selective emitter type, a diffusion layer having a higher impurity concentration than other regions is formed immediately below the electrode on the light receiving surface side. The barrier layer forming composition of the present invention can be used to form the high concentration diffusion layer region. In the double-sided light receiving type, finger bars and bus bars are formed on both surfaces as electrodes, and an n ⁺ -type diffusion layer is formed on one surface of the semiconductor substrate, and a p ⁺ -type diffusion layer is formed on the other surface. In order to selectively form the n ⁺ -type diffusion layer and the p ⁺ -type diffusion layer, the barrier layer forming composition of the present invention can be used.

In FIG. 1A, an alkaline solution is applied to a silicon substrate which is an n-type semiconductor substrate 10 to remove a damaged layer, and a texture structure is obtained by etching.
Specifically, the damaged layer on the surface of the silicon substrate generated when slicing from the ingot is removed with 20% by mass caustic soda. Next, etching is performed with a mixed solution of 1% by mass caustic soda and 10% by mass isopropyl alcohol to form a texture structure (the description of the texture structure is omitted in the figure). In the solar cell element, by forming a texture structure on the light receiving surface (front surface) side of the silicon substrate, a light confinement effect is promoted, and high efficiency is achieved.

In FIG. 1 (2), the barrier layer forming composition 11 of the present invention is applied to the front surface (that is, the light receiving surface) of the n-type semiconductor substrate 10 and the back surface opposite to the light receiving surface. In the present invention, the application method is not limited, but there are, for example, a printing method, a spin method, a brush coating, a spray method, a doctor blade method, a roll coater method, and an inkjet method, and the printing method or the inkjet method is used. preferable.
There is no particular limitation as application amount of the composition for forming a barrier layer, for ^example, it is possible to 0.01g / ^{m 2} ~100g / m 2 and ^{preferably, 0.1g / m 2 ~20g / m} 2 Is more preferable. There is no restriction | limiting in particular in the application | coating thickness of the said composition for barrier layer formation, It is preferable that they are 0.1 micrometer-50 micrometers, and it is more preferable that they are 1 micrometer-30 micrometers.

  Depending on the composition of the barrier layer forming composition, a drying step for volatilizing the dispersion medium contained in the composition may be necessary after application. In this case, drying is performed at a temperature of about 80 ° C. to 300 ° C. for 1 minute to 10 minutes when a hot plate is used, and about 10 minutes to 30 minutes when a dryer or the like is used. This drying condition depends on the content of the dispersion medium of the barrier layer forming composition and is not particularly limited to the above condition in the present invention.

  The patterned barrier layer can be obtained by applying the barrier layer forming composition 11 in a pattern in the case of a printing method, an inkjet method, or the like. On the other hand, in the case of spin method, brush coating, spray method, doctor blade method, roll coater method, etc., the barrier layer forming composition 11 is applied to the entire surface and then partially removed by etching or the like. .

Next, in FIG. 1C, coating diffusion materials 12 and 13 for forming an n ⁺ type diffusion layer and a p ⁺ type diffusion layer are applied. Next, in FIG. 1 (4), n ⁺ type diffusion layer 14 and p ⁺ type diffusion layer 15 are formed by thermal diffusion. By the heat treatment for thermal diffusion, the coating diffusion materials 12 and 13 become the fired products 12 ′ and 13 ′ of the coating diffusion material and generally form a glass layer. Although there is no restriction | limiting in particular as the heat processing temperature for thermal diffusion, It is preferable to heat-process on the conditions for 1 minute-300 minutes at the temperature of 750 to 1050 degreeC.
Here, a method of simultaneously forming the n ⁺ -type diffusion layer and the p ⁺ -type diffusion layer is illustrated, but the diffusion may be performed separately. That is, first, the application diffusion material 13 for forming the p ⁺ -type diffusion layer is applied and thermally diffused, and the fired product 13 ′ of the application diffusion material is removed, and then the application for forming the n ⁺ -type diffusion layer. The diffusion material 12 for application may be applied and thermally diffused, and the fired product 12 ′ of the diffusion material for application may be removed.

Although the case where the coating diffusion materials 12 and 13 are used has been described here, the present invention can be similarly applied to a method using POCl ₃ gas or BBr ₃ gas. In that case, first, in the n-type semiconductor substrate 10, a region where the p ⁺ -type diffusion layer is to be formed is used as an opening, and a barrier layer is formed using a composition for forming a barrier layer in addition to the region used as the opening, and BBr ₃ gas After forming a p ⁺ -type diffusion layer on the n-type semiconductor substrate 10 corresponding to the opening by using, the barrier layer is removed. Next, an area where the n ⁺ -type diffusion layer is to be formed is an opening, and a barrier layer is formed using the composition for forming a barrier layer in addition to the area to be the opening using POCl ₃ gas, and the opening is accommodated. An n ⁺ type diffusion layer is formed on the n type semiconductor substrate 10 to be formed.

Next, in FIG. 1 (5), the barrier layer forming composition 11 and the fired products 12 ′ and 13 ′ of the diffusion material for coating are removed to obtain a solar cell substrate. Examples of the removing method include a method of immersing in an aqueous solution containing an acid, and the barrier layer forming composition 11 and the coating diffusion material for forming the n ⁺ type diffusion layer and the p ⁺ type diffusion layer. It is preferable to determine the composition of the fired products 12 ′ and 13 ′. Specifically, it is preferable to include a step of etching the glass layer formed on the semiconductor substrate by the thermal diffusion treatment with an aqueous solution containing hydrofluoric acid. More specifically, an alkaline earth metal or a metal compound containing an alkali metal is removed with hydrochloric acid (for example, a 10% by mass HCl aqueous solution), washed with water, and further fired products 12 ′ and 13 ′ of the diffusion material for coating. Is etched with a hydrofluoric acid aqueous solution (for example, a 2.5% by mass HF aqueous solution) and then washed with water.

  Next, in FIG. 1 (6), an antireflection film 16 is provided on the front surface that is the light receiving surface, and a passivation film 17 is provided on the back surface. The antireflection film 16 and the passivation film 17 may have the same composition or different compositions. Examples of the antireflection film 16 include a silicon nitride film, and examples of the passivation film 17 include a silicon oxide film. Although there is no restriction | limiting in particular in the film thickness of an antireflection film and a passivation film, It is preferable to set it as 10 nm-300 nm, and it is more preferable to set it as 30 nm-150 nm.

  Next, in FIG. 1 (7), a portion for forming an electrode is opened in the passivation film 17. There is no particular limitation on the method of opening, and for example, the opening can be formed by applying an etching solution (for example, a solution containing hydrofluoric acid, ammonium fluoride, or phosphoric acid) to a portion where the opening is desired by an inkjet method or the like, and performing heat treatment.

Next, in FIG. 1 (8), an n electrode 18 and a p electrode 19 are formed on the n ⁺ type diffusion layer 14 and the p ⁺ type diffusion layer 15, respectively. In the present invention, the material and forming method of the electrodes 18 and 19 are not particularly limited. For example, the electrodes 18 and 19 may be formed by applying an electrode forming paste containing aluminum, silver, or copper metal and drying the paste. Next, the electrodes 18 and 19 are fired to complete the solar cell element.

  If the electrode forming paste includes glass frit, the opening process shown in FIG. 1 (7) can be omitted. When an electrode-forming paste containing glass frit is applied on the passivation film 17 and baked for several seconds to several minutes in the range of 600 ° C. to 900 ° C., the glass frit melts the passivation film 17 on the back side, and the metal particles in the paste (For example, silver particles) form a contact portion with the silicon substrate 10 and solidify. Thereby, the formed surface electrodes 18 and 19 and the silicon substrate 10 are electrically connected. This is called fire-through.

<Solar cell>
The solar cell includes one or more of the solar cell elements, and is configured by arranging a wiring material on the electrode of the solar cell element. In the solar cell, a plurality of solar cell elements may be connected via a wiring material as necessary, and may be further sealed with a sealing material.
The wiring material and the sealing material are not particularly limited, and can be appropriately selected from those usually used in the industry.

Examples of the present invention will be described more specifically below, but the present invention is not limited to these examples. Unless otherwise stated, all chemicals used reagents. “%” Means “% by mass” unless otherwise specified.
In addition, the volume average particle size of the alkaline earth metal or the metal compound containing the alkali metal in the examples is measured using a laser diffraction scattering method particle size distribution analyzer (LS 13 320 manufactured by Beckman Coulter), and the particle size in a dispersed state. Was measured.

<Example 1>
(Preparation of composition 1 for forming a barrier layer)
Terpineol (TPO, manufactured by Terpene Chemical Co., Terpineol) in which 20 g of calcium carbonate (manufactured by high purity chemical, volume average particle size 2.0 μm, amorphous particles) and 15% by mass of ethyl cellulose (EC, manufactured by Dow Chemical, STD200) are dissolved. LW) 40 g and terpineol 40 g were mixed to prepare composition 1 for forming a barrier layer.

(Preparation of phosphorus diffusion solution)
A 20% by mass aqueous solution of ammonium dihydrogen phosphate (manufactured by Wako Pure Chemical Industries, Ltd.) was prepared, and a saturated aqueous solution of ammonium dihydrogen phosphate as a supernatant was used as the phosphorus diffusion solution.

(Thermal diffusion and etching process)
On the surface of the n-type silicon substrate, the barrier layer forming composition 1 was applied by screen printing (MT-320T, manufactured by Microtech), dried for 5 minutes on a 150 ° C. hot plate, and then 1 on a 500 ° C. hot plate. Let dry for minutes. The thickness of the barrier layer obtained by drying was 6 μm. Next, another silicon substrate was prepared, and a phosphorus diffusion solution was spin-coated at 500 rpm (MS-A100, manufactured by Mikasa) and dried at 200 ° C.
With the two silicon substrates facing each other at a distance of 1 mm, the substrate was heated at 950 ° C. for 10 minutes to diffuse phosphorus into the silicon substrate coated with the barrier layer forming composition 1. Thereafter, the silicon substrate coated with the barrier layer forming composition 1 was immersed in an aqueous 10% by mass HCl solution for 5 minutes, washed with water, and further immersed in an aqueous 2.5% by mass HF solution for 5 minutes. After washing and drying this, the following evaluation was performed.

(Sheet resistance measurement)
The sheet resistance of the portion where the barrier layer forming composition 1 was applied was measured by a four-probe method using a Loresta-EP MCP-T360 type low resistivity meter manufactured by Mitsubishi Chemical Corporation. The sheet resistance of the portion to which the barrier layer forming composition 1 was applied was 240Ω / □. The sheet resistance of the uncoated part was 10Ω / □.

  As a reference sample, the sliced n-type silicon substrate was immersed in a 2.5% by mass HF aqueous solution for 5 minutes, and the sheet resistance after washing and drying was measured to be 240 Ω / □.

(Production of effective lifetime measurement substrate)
As the semiconductor substrate, a single crystal p-type silicon substrate (manufactured by SUMCO, 50 mm square, thickness: 625 μm) having a mirror-shaped surface was used. The silicon substrate was pre-treated by immersing and cleaning at 70 ° C. for 5 minutes using an RCA cleaning solution (Frontier Cleaner-A01 manufactured by Kanto Chemical).
Thereafter, the composition 1 for forming a semiconductor substrate passivation film obtained above is applied on one side of the substrate with a 45 mm square solid pattern on the silicon substrate that has been subjected to the above-described pretreatment, using a screen printing method. And dried for 3 minutes. Subsequently, after baking at 900 degreeC for 1 hour, it stood to cool at room temperature and produced the board | substrate for evaluation.

(Measurement of effective lifetime)
While immersing the evaluation substrate obtained above in a 0.5 mmol iodine / ethanol solution, the effective lifetime (μs) of the substrate was measured at room temperature using a lifetime measurement device (WT-2000PVN manufactured by Nippon Semi-Lab). It was measured by the reflected microwave photoconductive decay method. The effective lifetime of the region to which the composition for forming a semiconductor substrate passivation film of the obtained evaluation substrate was applied was 330 μs.

(Measurement of total lifetime killer element content)
The barrier layer forming composition 1 was dried at 200 ° C. for 30 minutes on a quartz boat. The total content of Fe, Mn, W, Au, Cr, and Ni contained in the obtained powder was measured by a microwave decomposition apparatus (Milestone) using a high frequency inductively coupled plasma mass spectrometry (ICP-MS) method. Measured using.

<Examples 2 to 8>
As in Example 1, except that Fe powder (high purity chemical laboratory, purity: 99.9% or higher), Mn powder (high purity chemical laboratory, purity: 99.9% or higher), Cr powder (high purity Purity Chemical Laboratory, Purity: 99.9% or higher), Ni Powder (High Purity Chemical Laboratory, Purity: 99.9% or higher), W Powder (High Purity Chemical Laboratory, Purity: 99.9% or higher) A predetermined amount of each was mixed to prepare barrier layer forming compositions of Examples 2 to 8 having the compositions shown in Table 1. Evaluation was performed in the same manner as in Example 1 using the barrier layer forming compositions of Examples 2 to 8. The results are shown in Table 2.

<Comparative Examples 1-7>
As in Example 1, except that Fe powder (high purity chemical laboratory, purity: 99.9% or higher), Mn powder (high purity chemical laboratory, purity: 99.9% or higher), Cr powder (high purity Purity Chemical Laboratory, Purity: 99.9% or higher), Ni Powder (High Purity Chemical Laboratory, Purity: 99.9% or higher), W Powder (High Purity Chemical Laboratory, Purity: 99.9% or higher) A predetermined amount of each was mixed to prepare barrier layer forming compositions of Comparative Examples 1 to 7 having the compositions shown in Table 1. Evaluation was performed in the same manner as in Example 1 using the barrier layer forming compositions of Comparative Examples 1 to 7. The results are shown in Table 2.

  As shown in the results of Table 2, by using a barrier layer forming composition containing an alkaline earth metal or a metal compound containing an alkali metal and a dispersion medium, diffusion of a donor element or an acceptor element is achieved. It can be sufficiently prevented, and by suppressing the content of the lifetime killer element in the composition for forming a barrier layer to 5% by mass or less, a decrease in the effective lifetime of the carrier of the semiconductor substrate after treatment is suppressed. be able to.

10 n-type semiconductor substrate 11 for forming a barrier layer composition 12 ^{n +} -type coating diffusion for forming the diffusion layer material 13 ^{p +} -type diffusion layer coated diffusion material for forming a 14 ^{n +} -type diffusion layer 15 p ⁺ Type diffusion layer 16 antireflection film 17 passivation film 18 n electrode 19 p electrode

Claims (12)

Containing an alkaline earth metal or a metal compound containing an alkali metal, and a dispersion medium,
The composition for barrier layer formation whose total content rate of iron, manganese, tungsten, gold | metal | money, chromium, and nickel is 5 mass% or less.   The composition for forming a barrier layer according to claim 1, wherein the total content of the iron, manganese, tungsten, gold, chromium, and nickel is 1% by mass or less.   The alkaline earth metal or the metal compound containing an alkali metal is selected from the group consisting of magnesium, calcium, sodium, potassium, lithium, rubidium, cesium, beryllium, strontium, barium, and radium as the metal element The composition for forming a barrier layer according to claim 1 or 2 comprising the above.   The alkaline earth metal or the metal compound containing an alkali metal is composed of magnesium oxide, calcium oxide, potassium oxide, magnesium carbonate, calcium carbonate, magnesium sulfate, calcium sulfate, calcium nitrate, magnesium hydroxide, and calcium hydroxide. The composition for forming a barrier layer according to any one of claims 1 to 3, comprising one or more selected from the above.   The metal compound containing the alkaline earth metal or alkali metal includes one or more selected from the group consisting of calcium carbonate, calcium oxide, and magnesium carbonate. The composition for forming a barrier layer as described.   The composition for forming a barrier layer according to any one of claims 1 to 5, wherein a total content of the alkaline earth metal or the metal compound containing the alkali metal is 0.1% by mass or more and less than 80% by mass. object.   The barrier layer according to any one of claims 1 to 6, wherein the dispersion medium includes one or more selected from the group consisting of water, alcohol solvents, glycol monoether solvents, and terpene solvents. Forming composition.   The composition for forming a barrier layer according to any one of claims 1 to 7, which is used for forming a mask for partially forming a diffusion layer on a semiconductor substrate. A semiconductor substrate;
A barrier layer that is a dried body of the composition for forming a barrier layer according to any one of claims 1 to 7 provided on the semiconductor substrate,
A semiconductor substrate with a barrier layer. Applying the barrier layer forming composition according to any one of claims 1 to 7 in a pattern on a semiconductor substrate to form a barrier layer;
Doping a donor element or an acceptor element from a portion where the barrier layer is not formed on the semiconductor substrate, and partially forming a diffusion layer in the semiconductor substrate;
The manufacturing method of the board | substrate for solar cells containing.   The method for producing a solar cell substrate according to claim 10, wherein the method for applying the barrier layer forming composition is a printing method or an inkjet method.   The manufacturing method of a solar cell element including the process of forming an electrode on the diffusion layer of the board | substrate for solar cells obtained by the manufacturing method of Claim 10 or Claim 11.