TWI759371B - Impurity diffusing agent composition and manufacturing method of semiconductor substrate - Google Patents

Abstract

An object of the present invention is to provide a diffusing agent composition and a method for manufacturing a semiconductor substrate using the diffusing agent composition, which has a nano-sized surface even on a semiconductor substrate to which impurity diffusing components are diffused. In the case of the three-dimensional structure of the micro-voids, it can be uniformly coated on the entire surface of the inner surface spanning the micro-voids, so that even when heated at a low temperature, boron can be well and uniformly diffused in the semiconductor substrate. As a solution, in the diffusing agent composition containing the impurity diffusing component (A), as the impurity diffusing component (A), a boron compound containing nitrogen atoms that can form a diffusion layer by coating on the surface of the semiconductor substrate is used.

Description

Impurity diffusing agent composition and manufacturing method of semiconductor substrate

The present invention relates to a diffusing agent composition having a boron compound containing nitrogen atoms as an impurity diffusing element, which can be applied to the surface of a semiconductor substrate to form a diffusing layer, and a diffusing agent composition formed by using the diffusing agent composition A thin film is a method of manufacturing a semiconductor substrate in which impurity diffusion components are diffused into the semiconductor substrate.

Semiconductor substrates used in semiconductor elements such as transistors, diodes, and solar cells are produced by diffusing impurity diffusion components such as phosphorus or boron on the semiconductor substrate. Regarding related semiconductor substrates, when manufacturing semiconductor substrates for multi-gate devices such as Fin-FETs, nanowire FETs, etc., for example, the semiconductor substrates having a 3-dimensional structure with nanoscale microscopic voids on the surface are subjected to impurity treatment. diffusion.

Here, as a method of diffusing the impurity-diffused components on the semiconductor substrate, for example, an ion implantation method (for example, refer to Patent Document 1) or a CVD method (for example, refer to Patent Document 2) is known. In the ion implantation method, the ionized impurity diffusion components are impregnated into the surface of the semiconductor substrate. In the CVD method, after an oxide film such as silicon oxide doped with impurity diffusion components such as phosphorus or boron is formed on a semiconductor substrate by CVD, a half of the oxide film is formed. The conductor substrate is heated by an electric furnace or the like, so that the impurity diffusion components are diffused from the oxide film to the semiconductor substrate.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 06-318559

[Patent Document 2] International Publication No. 2014/064873

However, in the ion implantation method described in Patent Document 1, when light ions such as B (boron) are implanted into a semiconductor substrate, point defects or point defect clusters are likely to be formed in a region near the substrate surface. For example, when impurity diffusion components are diffused on a semiconductor substrate by ion implantation to form a CMOS device such as a CMOS image sensor, the occurrence of such defects will directly degrade the performance of the device.

Also, a semiconductor substrate, for example, has on its surface a multi-gate element for forming fins having a plurality of sources and a plurality of attractors, and a gate perpendicular to these fins and called a Fin-FET. In the case of a three-dimensional nanoscale structure of a three-dimensional structure, in the ion implantation method, it is difficult to implant uniform ions into the sides and upper surfaces of the fins or gates or the inner surfaces of the recesses sandwiched by the fins and the gates.

In addition, when the impurity diffusion components are diffused in the semiconductor substrate having the nano-sized three-dimensional structure by the ion implantation method, even if the Into the uniform ions, there will be the following problems. For example, when a logic LSI device or the like is formed using a semiconductor substrate having a three-dimensional pattern having fine fins, crystals of substrate materials such as silicon are easily destroyed by ion implantation. The related crystal damage can lead to inconveniences such as uneven device characteristics and generation of standby leakage current.

In addition, when the CVD method as described in Patent Document 2 is applied, it is difficult to obtain an oxide containing an impurity diffusion component with a uniform film thickness on the entire inner surface of the concave portion sandwiched by the fin and the gate due to the overhang phenomenon. There is a problem that the opening is blocked due to the oxide deposited on the opening of the concave portion sandwiched by the fin and the gate. Therefore, by the ion implantation method or the CVD method, it is difficult to diffuse the impurity diffusion components well and uniformly in the semiconductor substrate due to the surface shape of the semiconductor substrate.

In order to solve the related problems, it is considered to use a coating-type diffusing agent composition.

In a substrate with a three-dimensional structure with nano-sized micro-voids on its surface, as long as the coating-type diffusing agent composition can be uniformly coated on the entire surface of the inner surface including the micro-voids, in the surface with the relevant three-dimensional surface. In the semiconductor substrate, impurities such as boron can be uniformly diffused.

In addition, as for the coating-type diffusing agent composition, it is desired that the cycle of heating and cooling can be shortened or that impurities can be diffused well even when heated at a low temperature. With the 3D transformation, the control of the diffusion length becomes more and more necessary, but the diffusion length can be shortened by heating at a low temperature for diffusion.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a diffusing agent composition which is a target of diffusing impurity diffusing components Even when the surface of the semiconductor substrate has a three-dimensional structure with microscopic voids of nanometer size, it can be uniformly coated on the entire surface of the inner surface spanning the microscopic voids, so that, for example, when heated at a low temperature of 1000°C or less, it can also be used. A method of making boron well and uniformly diffused in a semiconductor substrate and a semiconductor substrate using the diffusing agent composition.

The present inventors found that in the diffusing agent composition containing the impurity diffusing component (A), as the impurity diffusing component (A), a boron compound containing nitrogen atoms capable of forming a diffusion layer by coating on the surface of a semiconductor substrate is used , the above problems can be solved, and the present invention can be further completed. More specifically, the present invention provides the following.

A first aspect of the present invention is a diffusing agent composition, which is a diffusing agent composition for impurity diffusion to a semiconductor substrate, and includes an impurity diffusing component (A), which can be applied by coating on A diffusion layer is formed on the surface of the semiconductor substrate, and is a boron compound containing nitrogen atoms.

A second aspect of the present invention is a method for manufacturing a semiconductor substrate, comprising: coating the first aspect of the diffusing agent composition on the semiconductor substrate to form a coating film, and diffusing an impurity component (A) in the diffusing agent composition Diffusion to semiconductor substrates.

According to the present invention, a semiconductor substrate which is an object of diffusing impurity diffusion components can be uniformly coated on the entire surface of the inner surface spanning the tiny voids even when the surface thereof has a three-dimensional structure with tiny voids of nanometer size on its surface. Thereby, even when heating at a low temperature of 1000° C. or lower, boron can be well and uniformly diffused in the diffusing agent composition of the semiconductor substrate and the manufacturing method of the semiconductor substrate using the diffusing agent composition.

<<Diffuser composition>>

A diffusing agent composition for impurity diffusion to a semiconductor substrate, and containing an impurity diffusing component (A).

The impurity diffusion component (A) is a boron compound that can form a diffusion layer by coating on the surface of a semiconductor substrate and contains nitrogen atoms.

By using the relevant impurity diffusion component (A) and using the diffusing agent composition, boron can be favorably diffused into the semiconductor substrate.

Furthermore, by using the above-mentioned diffusing agent composition, when the surface of the semiconductor substrate to which the impurity diffusing component is diffused has a three-dimensional structure having microscopic voids of nanometer size on its surface, the entire inner surface of the microscopic voids can also be included, so that the The diffusing agent composition is uniformly coated on the surface of the semiconductor substrate. Thereby, boron is uniformly diffused in the semiconductor substrate.

The following describes the necessary or optional components contained in the diffusing agent composition Element.

[Impurity diffusion component (A)]

The impurity diffusion component (A) can be applied to the surface of the semiconductor substrate to form a diffusion layer, and is a boron compound containing nitrogen atoms.

For example, the boron compound containing nitrogen atom will be in The substrate surface is arranged with a thickness of about 1 to several molecules to form a diffusion layer.

Furthermore, from the viewpoint of the adsorption property of the boron compound on the substrate surface, it is preferable that the boron atom in the boron compound is not in a tetravalent state. As an example of the boron compound in which the boron atom is in a tetravalent state, there is a complex compound such as a complex of triethylamine and BH ₃ .

As a boron compound that satisfies the above-mentioned specific conditions, it is, for example, the following formula (a1) or the following formula (a2):

(In formula (a1), R ¹ , R ² , R ³ , and R ⁴ are each independently a hydrogen atom, a hydroxyl group, an organic group not containing a nitrogen atom, or a group containing a nitrogen atom, and R ¹ , R ² , R ³ , and at least one of R ⁴ is a nitrogen atom-containing group, R ¹ and R ² and, R ² and R ⁴ and, R ³ and R ⁴ and, and R ¹ and R ³ can also be independently bonded to each other to form ring.

In formula (a2), R ⁵ , R ⁶ , and R ⁷ are each independently a hydrogen atom, a hydroxyl group, an organic group not containing a nitrogen atom, or a group containing a nitrogen atom, and at least 1 of R ⁵ , R ⁶ , and R ⁷ Each is a nitrogen atom-containing group, and two of R ⁵ , R ⁶ , and R ⁷ may be bonded to each other to form a ring. )

The compounds represented are preferred.

In the formula (a1), as the nitrogen atom-free organic group of R ¹ , R ² , R ³ , and R ⁴ , a hetero atom other than a nitrogen atom may be included. As an example of a hetero atom, O, S, B, etc. are mentioned.

The nitrogen atom-free organic group of R ¹ , R ² , R ³ , and R ⁴ is not particularly limited, and suitable examples include a group represented by -R ^a1 and a group represented by -OR ^a1 .

R ^a1 is a hydrocarbon group which may have a substituent, or a heterocyclic group which may have a substituent.

When R ^a1 is a hydrocarbon group having a substituent, suitable examples of the hydrocarbon group include an alkyl group, an aliphatic cyclic group, a cycloalkylalkyl group, an alkenyl group, and an aromatic hydrocarbon group. The number of carbon atoms in the hydrocarbon group is not particularly limited, but is preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 6.

The alkyl group may be linear or branched. Suitable examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-butyl -hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-decyl Five bases, n-hexadecyl bases, n-heptadecyl bases, n-octadecyl bases, n-nineteen bases, and n-twenty bases.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. Examples of the monocyclic group include cyclopentyl, cyclohexyl, and cycloheptyl etc. cycloalkyl. As a polycyclic group, an adamantyl group, a norbornyl group, an isobornyl group, a tricyclononyl group, a tricyclodecyl group, a tetracyclododecyl group, and the like are exemplified.

Examples of the cycloalkylalkyl group include cyclopentylmethyl, 2-cyclopentylethyl, 3-cyclopentylpropyl, 4-cyclopentylbutyl, cyclohexylmethyl, and 2-cyclohexylethyl , 3-cyclohexylpropyl, and 4-cyclohexylbutyl.

The alkenyl group may be linear or branched. As a suitable example of an alkenyl group, the alkenyl group corresponding to the suitable example of the said alkyl group is mentioned. A vinyl group and an allyl group are mentioned as a particularly preferable alkenyl group.

Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a biphenyl group. Among these, a phenyl group is preferred.

When R ^a1 is a heterocyclic group which may have a substituent, the heterocyclic group is not particularly limited as long as the heterocyclic group does not contain a nitrogen atom.

Suitable examples of the heterocyclic group include a furanyl group, a thienyl group, a piperanyl group, a thiopyranyl group, a tetrahydrofuranyl group, and a tetrahydrothienyl group.

When R ^a1 is a group having a substituent, suitable examples of the substituent include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, a mercapto group, and a carbon number of 2. Aliphatic alkoxy groups of ~7, benzyl groups, alkoxycarbonyl groups of 2 to 7 carbon atoms, and phenoxycarbonyl groups, etc.

When R ^a1 has plural substituents, the plural substituents may be different from each other.

When R ¹ , R ² , R ³ , and R ⁴ are a nitrogen atom-containing group, the nitrogen atom-containing group may be an organic group or an inorganic group.

Suitable examples of the nitrogen atom-containing group include an amine group, an isocyanate group, and an organic group containing a nitrogen atom.

Examples of the organic group containing a nitrogen atom include a group represented by -NHR ^a1 , a group represented by -N(R ^a1 ) ₂ , a group represented by -R ^a2 -(R ^a3 ) _p , and -OR ^a2 - (R ^a3 ) The basis represented by _p .

R ^a1 is as described above. When the organic group containing a nitrogen atom contains plural R ^a1s , the plural R ^a1s in the organic group may be different from each other. Suitable examples of R ^a2 are the same as those of R ^a1 .

R ^a2 is a group that removes the (p+1) valence of p hydrogen atoms from the aforementioned R ^a1 .

R ^a3 is a group selected from the group consisting of a nitro group, a cyano group, an amino group, an isocyanate group, a mono- or dialkylamine group having an alkyl group having 1 to 6 carbon atoms, and a carbamoyl group. When the organic group containing a nitrogen atom contains plural R ^a3 , the plural R ^a3 in the organic group may be different from each other.

p is the substitution number of -R ^a3 in the group represented by -OR ^a2 -(R ^a3 ) _p . p is an integer of 1 or more. The upper limit of p is appropriately set according to the number of carbon atoms of R ^a2 . p is typically an integer of 1 to 6, preferably an integer of 1 to 3, more preferably an integer of 1 to 3, particularly preferably 1 or 2, and most preferably 1.

In the formula (a1), R ¹ and R ² and, R ² and R ⁴ and, R ³ and R ⁴ and, and R ¹ and R ³ are each independently bonded to each other to form a ring.

At this time, as a divalent group formed by R ¹ and R ² and, R ² and R ⁴ and, R ³ and R ⁴ and, or R ¹ and R ³ are bonded together, the following formulas (i)~ (viii) the basis indicated.

-NR ^a4 -R ^a5 -NR ^a4 -‧‧‧(i)

-NR ^a4 -BH-NR ^a4 -‧‧‧(ii)

-NR ^a4 -BH-BH-NR ^a4 -‧‧‧(iii)

-NR ^a4 -BH-NR ^a4 -NR ^a4 -‧‧‧(iv)

-NR ^a4 -NR ^a4 -NR ^a4 -NR ^a4 -‧‧‧(v)

-NR ^a4 -BH-NR ^a4 -BH-NR ^a4 -‧‧‧(vi)

-OR ^a5 -O-‧‧‧(vii)

-OR ^a6 -O-‧‧‧(viii)

In the above formulae (i) to (viii), R ^a4 is a hydrogen atom, a group represented by -R ^a1 , a group represented by -OR ^a1 , or a group represented by -CO-R ^a1 . In formulae (i) to (viii), the plural R ^a4 may be the same or different.

R ^a5 in formula (i) and formula (vii) may be a linear or branched alkylene group. Suitable examples of the alkylene group include -CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ -, -CH ₂ CH ₂ CH(CH ₂ CH ₃ )-, -CH ₂ CH ₂ CH(CH ₂ CH ₃ )-, -CH ₂ -C(CH ₃ ) ₂ -CH ₂ -, and -C(CH ₃ ) ₂ C(CH ₃ ) ₂ -.

R ^a6 in the formula (viii) is a divalent group obtained by removing two hydroxyl groups from an amide tartrate compound.

In formula (a2), R ⁵ , R ⁶ , and R ⁷ are each independently a hydrogen atom, a hydroxyl group, an organic group not containing a nitrogen atom, or a group containing a nitrogen atom. Examples of these groups are the same as those described for R ¹ , R ² , R ³ , and R ⁴ in the formula (a1).

In addition, in formula (a2), two of R ⁵ , R ⁶ , and R ⁷ may be bonded to each other to form a ring. At this time, as a divalent group formed by R ⁵ and R ⁶ and, R ⁶ and R ⁷ and, or R ⁵ and R ⁷ are bonded, there are groups represented by the aforementioned formulae (i) to (vi).

Suitable examples of the compound represented by the following formula (a1) and suitable examples of the compound represented by the formula (a2) will be described in more detail.

A suitable example of the compound represented by the formula (a1) is the following formula (a1-1):

(In formula (a1-1), R ⁸ to R ¹⁵ are independently a hydrogen atom, an aliphatic hydrocarbon group with 1 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 10 carbon atoms, and an aromatic hydrocarbon group with 7 to 12 carbon atoms. Alkyl group, aliphatic alkyl group with 2 to 10 carbon atoms, or aromatic alkyl group with 7 to 11 carbon atoms. R ⁸ and R ⁹ and, R ¹⁰ and R ¹¹ and, R ¹² and R ¹³ and, and R ¹⁴ and R ¹⁵ may be independently bonded to each other to form a ring.)

The aliphatic hydrocarbon group of R ⁸ to R ¹⁵ may be a straight chain, a branched chain, a saturated hydrocarbon group, or an unsaturated hydrocarbon group. The aliphatic hydrocarbon groups for R ⁸ to R ¹⁵ are preferably straight-chain saturated hydrocarbon groups.

The number of carbon atoms of the aliphatic hydrocarbon group used as R ⁸ to R ¹⁵ is preferably 1 to 6, more preferably 1 to 4, and particularly preferably 1 to 3.

Suitable examples of the aliphatic hydrocarbon groups for R ⁸ to R ¹⁵ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. , n-heptyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl are methyl, ethyl, n-propyl, and Isopropyl is preferred, and methyl and ethyl are more preferred.

The number of carbon atoms of the aromatic hydrocarbon group as R ⁸ to R ¹⁵ is 6 to 10. Suitable examples of the aromatic hydrocarbon groups for R ⁸ to R ¹⁵ are phenyl, α-naphthyl, and β-naphthyl, and phenyl is preferred.

The number of carbon atoms of the aralkyl group as R ⁸ to R ¹⁵ is 7 to 12. Suitable examples of the aralkyl group for R ⁸ to R ¹⁵ are benzyl, phenethyl, α-naphthylmethyl, and β-naphthylmethyl, and preferably benzyl and phenethyl.

The aliphatic acyl group of R ⁸ to R ¹⁵ may be linear or branched, and may optionally have an unsaturated bond. The aliphatic acid group of R ⁸ to R ¹⁵ is preferably a linear saturated aliphatic acid group.

The number of carbon atoms of the aliphatic acid group used as R ⁸ to R ¹⁵ is preferably 2 to 6, more preferably 2 to 4, and particularly preferably 2 or 3.

Suitable examples of the aliphatic acyl group for R ⁸ to R ¹⁵ include acetyl group, propionyl group, n-butyryl group, n-pentyl group, n-hexyl group, n-heptanyl group, n- Octyl, n-nonanoyl, and n-decanoyl are acetyl, propionyl, n-butyryl, n-pentyl, and n-hexyl, preferably acetyl, and propyl Acyl-based is further preferred.

The number of carbon atoms of the aromatic aryl group as R ⁸ to R ¹⁵ is 7 to 11. Suitable examples of the aromatic benzyl group for R ⁸ to R ¹⁵ are benzyl, α-naphthyl, and β-naphthyl, and benzyl is more preferred.

Suitable specific examples of the compound represented by the formula (a1-1) include the following compounds.

Another suitable example of the compound represented by the formula (a1) is the following formula (a1-2):

(In formula (a1-2), R ¹⁶ and R ¹⁷ are each a divalent organic group.)

As a divalent organic group of R ¹⁶ and R ¹⁷ , a group represented by -R ¹⁸ -NR ²⁰ -R ¹⁹ - and a group derived from amide tartrate are exemplified.

The group derived from amide tartrate means a divalent group from which 2 hydroxyl groups are removed from the amide tartrate compound.

R ¹⁸ and R ¹⁹ are each independently an alkylene group having 1 to 6 carbon atoms, preferably a methylene group or an ethane-1,2-diyl group. R ²⁰ is a hydrogen atom, an aliphatic hydrocarbon group with 1 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 10 carbon atoms, an aralkyl group with 7 to 12 carbon atoms, and an aliphatic acyl group with 2 to 10 carbon atoms , or an aromatic aryl group having 7 to 11 carbon atoms, and specific examples thereof are the same as those described for R ⁸ to R ¹⁵ .

In the formula (a1-2), when R ¹⁶ and R ¹⁷ are groups derived from amide tartrate, suitable specific examples of the compound represented by the formula (a1-2) include the following formula (a1-2- 1):

(In formula (a1-2-1), R ²¹ to R ²⁸ are each independently a hydrogen atom, an aliphatic hydrocarbon group with 1 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 10 carbon atoms, and a hydrocarbon group with 7 to 12 carbon atoms. aralkyl group, aliphatic aryl group with 2 to 10 carbon atoms, or aromatic aryl group with 7 to 11 carbon atoms.)

the indicated compound.

Regarding R ²¹ to R ²⁸ , hydrogen atom, aliphatic hydrocarbon group with 1 to 10 carbon atoms, aromatic hydrocarbon group with 6 to 10 carbon atoms, aralkyl group with 7 to 12 carbon atoms, and aralkyl group with 2 to 10 carbon atoms Specific examples of the aliphatic acid group and the aromatic acid group having 7 to 11 carbon atoms are the same as those described for R ⁸ to R ¹⁵ .

Suitable specific examples of the compound represented by the formula (a1-2-1) include the following compounds.

In addition, as a suitable specific example of the compound represented by formula (a2), the following formula (a2-1) is exemplified:

(In formula (a2-1), R ²⁹ is a nitrogen-containing heterocyclic group, or a cyclic group substituted with a nitrogen-containing group that does not contain a nitrogen atom, and R ³⁰ and R ³¹ are independently a hydrogen atom and the number of carbon atoms. Aliphatic hydrocarbon group of 1 to 10, aromatic hydrocarbon group of 6 to 10 carbon atoms, aralkyl group of carbon number of 7 to 12, aliphatic group of carbon number of 2 to 10, or carbon number of 7 to 11 Aromatic acid group. R ³⁰ and R ³¹ may also be bonded to each other to form a ring)

the indicated compound.

R ²⁹ is a nitrogen-containing heterocyclic group which may also be substituted with a nitrogen-containing group, or a cyclic group which does not contain a nitrogen atom and is substituted with a nitrogen-containing group. That is, R ²⁹ is a cyclic group that must contain a nitrogen atom.

The nitrogen-containing heterocyclic group as R ²⁹ may be a nitrogen-containing aromatic heterocyclic group or a nitrogen-containing aliphatic heterocyclic group.

The nitrogen-containing heterocyclic group is a monovalent group obtained by removing one hydrogen atom from various nitrogen-containing heterocycles. The hydrogen atom removed from the nitrogen-containing heterocyclic ring may be bonded to any atom constituting the ring, may be bonded to a carbon atom, may be bonded to a nitrogen atom, or may be bonded to a heteroatom other than the nitrogen atom.

Suitable examples of the nitrogen-containing aromatic heterocycle to which the nitrogen-containing heterocyclic group is given include pyrrole, oxazole, isoxazole, oxadiazole, thiazole, isothiazole, thiadiazole, imidazole, pyrazole, Triazole, pyridine, pyrazine, pyrimidine, pyridazine, triazine, tetrazine, pentaazine, indole, isoindole, indolizine, benzimidazole, benzotriazole, benzoxazole, benzothiazole, Carbazole, purine, quinoline, isoquinoline, quinazoline, phthalazine, cinnoline, quinoxaline and the like.

Suitable examples of the nitrogen-containing aliphatic heterocyclic ring to which the nitrogen-containing heterocyclic group is given include pyridine, pyrazoline, triazolidine, dihydropyrrole, pyrazoline, imidazoline, triazoline, and piperidine. pyridine, piperazine, triazacyclohexane, tetraazacyclohexane, pentazacyclohexane, morpholine, thiomorpholine, ε-caprolactam, δ-valerolactam, γ-Butyrolactone, 2-Tetrahydroimidazolone, Phthalate Amine, s-triazine-2,4,6-trione, etc.

When R ²⁹ is a cyclic group that is substituted by a nitrogen-containing group and does not contain a nitrogen atom, the cyclic group may also be an aromatic group, an aliphatic cyclic group, or a group containing a heteroatom other than a nitrogen atom. Heterocyclyl.

The cyclic group is preferably an aromatic group, preferably a phenyl group, a naphthyl group, and a biphenyl group, and even more preferably a phenyl group.

When R ²⁹ is a cyclic group that is substituted with a nitrogen-containing group and does not contain a nitrogen atom, suitable examples of the nitrogen-containing group of the substituent include a nitro group, an isocyanate group, and those represented by -NR ³¹ R ³² An amino group or a substituted amino group, a carbamoyl group represented by -CONH-R ³³ or a substituted carbamoyl group.

In addition, as a group containing a boron atom and a nitrogen atom represented by the following formula, it is also preferable as a nitrogen-containing group.

Among the amino groups or substituted amino groups represented by -NR ³¹ R ³² , suitable examples of R ³¹ and R ³² are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and an aliphatic hydrocarbon group having 6 to 10 carbon atoms. An aromatic hydrocarbon group, an aralkyl group with 7 to 12 carbon atoms, an aliphatic aryl group with 2 to 10 carbon atoms, or an aromatic aryl group with 7 to 11 carbon atoms.

R ³¹ and R ³² may be bonded to each other to form a ring.

Specific examples of these bases are the same as those described for R ⁸ to R ¹⁵ .

Suitable examples of R ³³ in the carbamoyl group or substituted carbamoyl group represented by -CONH-R ³³ are each independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and a group having 6 to 10 carbon atoms. An aromatic hydrocarbon group, an aralkyl group with 7 to 12 carbon atoms, an aliphatic aryl group with 2 to 10 carbon atoms, or an aromatic aryl group with 7 to 11 carbon atoms.

Specific examples of these bases are the same as those described for R ⁸ to R ¹⁵ .

Among the nitrogen-containing groups described above, preferred are nitro, amino, dimethylamino, diethylamino, diphenylamino, phenylamino, carbamoyl, and isocyanate groups, It is more preferably a nitro group and an amine group.

When R ²⁹ is a cyclic group containing no nitrogen atom substituted with a nitrogen-containing group, the number of nitrogen-containing groups on the cyclic group is not particularly limited. The number of nitrogen-containing groups on the cyclic group is preferably 1 to 4, 1 or 2 is more preferred, and 1 is particularly preferred.

Suitable specific examples of the compound represented by the formula (a2-1) include the following compounds.

Another suitable specific example of the compound represented by the formula (a2) is the following formula (a2-2):

(In formula (a2-2), R ³⁴ and R ³⁵ are independently a hydrogen atom, a hydroxyl group, an aliphatic hydrocarbon group with 1 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 10 carbon atoms, and a carbon number of 7 to 12. The aralkyl group, the aliphatic aryl group with 2 to 10 carbon atoms, or the aromatic aryl group with 7 to 11 carbon atoms, R ³⁶ and R ³⁷ are independently a hydrogen atom and an aliphatic group with 1 to 10 carbon atoms. Hydrocarbon group, aromatic hydrocarbon group with 6 to 10 carbon atoms, aralkyl group with 7 to 12 carbon atoms, aliphatic aryl group with 2 to 10 carbon atoms, or aromatic aryl group with 7 to 11 carbon atoms. R ³⁴ and R ³⁵ may also be bonded to each other to form a ring. R ³⁴ and R ³⁶ may also be bonded to each other to form a ring. R ³⁵ and R ³⁷ may also be bonded to each other to form a ring. R ³⁶ and R ³⁷ may also be bonded to each other to form a ring .)

R ³⁴ , R ³⁵ , R ³⁶ and R ³⁷ are aliphatic hydrocarbon groups having 1 to 10 carbon atoms, aromatic hydrocarbon groups having 6 to 10 carbon atoms, aralkyl groups having 7 to 12 carbon atoms, and 2 to 2 carbon atoms. In the case of the aliphatic group of 10 or the aromatic group of carbon atoms of 7 to 11, specific examples of these groups are the same as those described for R ⁸ to R ¹⁵ .

R ³⁴ and R ³⁵ are preferably hydrogen atoms. As R ³⁶ and R ³⁷ , an aliphatic hydrocarbon group having 1 to 10 carbon atoms is preferred, an alkyl group having 1 to 10 carbon atoms is more preferred, an alkyl group having 1 to 6 carbon atoms is still more preferred, and The alkyl group having 1 to 3 carbon atoms is particularly preferred.

When R ³⁴ and R ³⁶ are bonded to each other to form a ring, or R ³⁵ and R ³⁷ are bonded to each other to form a ring, the divalent group formed by R ³⁴ and R ³⁶ or R ³⁵ and R ³⁷ is preferably, for example, an alkylene group. As the alkylene group, for example, trimethylene and tetramethylene are preferable.

That is, it is preferable that R ³⁴ and R ³⁶ or R ³⁵ and R ³⁷ together with a boron atom and a nitrogen atom form a saturated aliphatic 5-membered ring or a saturated aliphatic 6-membered ring.

Suitable specific examples of the compound represented by the formula (a2-2) include the following compounds.

Other suitable specific examples of the compound represented by the formula (a2) include the following formula (a2-3):

(In formula (a2-3), R ³⁸ is a nitrogen-containing heterocyclic group, or a cyclic group substituted by a nitrogen-containing group that does not contain a nitrogen atom, R ³⁹ and R ⁴⁰ are independently a hydrogen atom and the number of carbon atoms. Aliphatic hydrocarbon group of 1 to 10, aromatic hydrocarbon group of 6 to 10 carbon atoms, aralkyl group of carbon number of 7 to 12, aliphatic group of carbon number of 2 to 10, or carbon number of 7 to 11 Aromatic halide group. R ³⁹ and R ⁴⁰ may also be bonded to each other to form a ring.)

the indicated compound.

Suitable examples of the nitrogen-containing heterocyclic group as R ³⁸ or the cyclic group that does not contain a nitrogen atom substituted with a nitrogen-containing group are the same as those described for R ²⁹ in the formula (a2-1).

R ³⁹ and R ⁴⁰ are aliphatic hydrocarbon groups with 1 to 10 carbon atoms, aromatic hydrocarbon groups with 6 to 10 carbon atoms, aralkyl groups with 7 to 12 carbon atoms, and aliphatic acyl groups with 2 to 10 carbon atoms , or an aromatic aryl group having 7 to 11 carbon atoms, specific examples of these groups are the same as those described for R ⁸ to R ¹⁵ .

Among the compounds represented by the formula (a2-3), -OR ³⁹ and -OR ⁴⁰ are preferably compounds having the following structures.

Suitable specific examples of the compound represented by the formula (a2-3) include the following compounds.

Other suitable specific examples of the compound represented by the formula (a2) include the following formula (a2-4):

(In formula (a2-4), R ⁴¹ and R ⁴² are independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, and an aromatic hydrocarbon group having 7 to 12 carbon atoms. An alkyl group, an aliphatic aryl group having 2 to 10 carbon atoms, or an aromatic aryl group having 7 to 11 carbon atoms.

R ⁴³ is an alkylene group having 1 to 10 carbon atoms, -BR ⁴⁵ -, -BR ⁴⁵ -BR ⁴⁵ -, -BR ⁴⁵ -NR ⁴⁶ -, -NR ⁴⁶ -NR ⁴⁶ -, -BR ⁴⁵ -NR ⁴⁶ - BR ⁴⁵ -, or, -BR ⁴⁵ -NR ⁴⁶ -BR ⁴⁵ -NR ⁴⁶ -BR ⁴⁵ -.

R ⁴⁶ is independently a hydrogen atom, an aliphatic hydrocarbon group with 1 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 10 carbon atoms, an aralkyl group with 7 to 12 carbon atoms, and an aliphatic group with 2 to 10 carbon atoms An acyl group, or an aromatic acyl group having 7 to 11 carbon atoms.

R ⁴⁴ and R ⁴⁵ are independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an aralkyl group having 2 to 10 carbon atoms. aliphatic group, aromatic group with 7 to 11 carbon atoms, nitrogen-containing heterocyclic group, or cyclic group not containing nitrogen atom substituted by nitrogen-containing group. )

the indicated compound.

R ⁴¹ , R ⁴² , R ⁴⁴ , R ⁴⁵ , and R ⁴⁶ are aliphatic hydrocarbon groups having 1 to 10 carbon atoms, aromatic hydrocarbon groups having 6 to 10 carbon atoms, aralkyl groups having 7 to 12 carbon atoms, and carbon In the case of an aliphatic alkyl group having 2 to 10 atoms or an aromatic alkyl group having 7 to 11 carbon atoms, specific examples of these groups are the same as those described for R ⁸ to R ¹⁵ .

When R ⁴⁴ and R ⁴⁵ are a nitrogen-containing heterocyclic group or a nitrogen-containing group substituted with a cyclic group not containing a nitrogen atom, specific examples of these groups are the same as those described for R ²⁹ .

Among the compounds represented by the formula (a2-4), compounds represented by the following formulae (a2-4-1) to (a2-4-8) are preferred.

The compound represented by the formula (a2-4-6) is preferably, for example, a compound represented by the following formula.

As the compound represented by the formula (a2-4-7), for example, a compound represented by the following formula is preferable.

Suitable specific examples of the compound represented by the formula (a2-4) include the following compounds.

Other suitable specific examples of the compound represented by the formula (a2) include the following formula (a2-5):

(In formula (a2-5), R ⁴⁶ to R ⁵¹ are each independently a hydrogen atom, an aliphatic hydrocarbon group with 1 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 10 carbon atoms, and an aromatic hydrocarbon group with 7 to 12 carbon atoms. Alkyl group, aliphatic alkyl group having 2 to 10 carbon atoms, or aromatic alkyl group having 7 to 11 carbon atoms. R ⁴⁶ and R ⁴⁷ and R ⁴⁸ and R ⁴⁹ and R ⁵⁰ and R ⁵¹ may also be They are independently bonded to each other to form a ring.)

the indicated compound.

R ⁴⁶ to R ⁵¹ are aliphatic hydrocarbon groups with 1 to 10 carbon atoms, aromatic hydrocarbon groups with 6 to 10 carbon atoms, aralkyl groups with 7 to 12 carbon atoms, and aliphatic aryl groups with 2 to 10 carbon atoms , or an aromatic aryl group having 7 to 11 carbon atoms, specific examples of these groups are the same as those described for R ⁸ to R ¹⁵ .

Suitable specific examples of the compound represented by the formula (a2-5) include the following compounds.

The content of the impurity diffusing component (A) in the diffusing agent composition is not particularly limited. The content of the impurity diffusing component (A) in the diffusing agent composition is preferably 0.01 to 20% by mass, more preferably 0.05 to 15% by mass, and particularly preferably 0.1 to 10% by mass.

[Hydrolyzable Silane Compound (B)]

The diffusing agent composition may contain the hydrolyzable silane compound (B). When the diffusing agent composition contains the hydrolyzable silane compound (B), the diffusing agent composition When coating on a semiconductor substrate to form a thin film, the hydrolyzable silane compound is hydrolyzed and condensed to form an extremely thin film of silicon oxide type in the coating film. When an extremely thin film of silicon oxide system is formed in the coating film, the diffusion of the impurity-diffusing component (A) to the outside of the substrate can be suppressed, and the film formed of the diffusing agent composition can be well and uniformly applied even if it is a thin film. The impurity diffusion component (A) is diffused in the semiconductor substrate.

The hydrolyzable silane compound (B) has a functional group in which a hydroxyl group is generated by hydrolysis and is bonded to an Si atom. As a functional group which produces|generates a hydroxyl group by hydrolysis, an alkoxy group, an isocyanate group, a dimethylamine group, a halogen atom, etc. are mentioned. The alkoxy group is preferably a linear or branched aliphatic alkoxy group having 1 to 5 carbon atoms. As a specific example of a suitable alkoxy group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, etc. are mentioned. The halogen atom is preferably a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom, and more preferably a chlorine atom.

As a functional group that generates a hydroxyl group by hydrolysis, it is an isocyanate group and a straight chain having 1 to 5 carbon atoms from the viewpoint of the ease of being hydrolyzed and rapidly hydrolyzed and the hydrolyzable silane compound (B). Or branched aliphatic alkoxy groups are preferable, and methoxy groups, ethoxy groups, and isocyanate groups are more preferable.

Specific examples of the hydrolyzable silane compound (B) having a linear or branched aliphatic alkoxy group having 1 to 5 carbon atoms include tetramethoxysilane, tetraethoxysilane, tetramethoxysilane, and tetramethoxysilane. -n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetra-n-pentyloxysilane, trimethoxymonoethoxysilane, dimethoxydiethoxy Silane, Monomethoxy Triethoxysilane, trimethoxymono-n-propoxysilane, dimethoxydi-n-propoxysilane, monomethoxytri-n-propoxysilane, trimethoxymono-n -Butoxysilane, dimethoxydi-n-butoxysilane, monomethoxytri-n-tributoxysilane, trimethoxymono-n-pentyloxysilane, dimethoxysilane Di-n-pentyloxysilane, monomethoxytri-n-pentyloxysilane, triethoxymono-n-propoxysilane, diethoxydi-n-propoxysilane, monoethoxytri-n-propoxysilane, triethoxymono-n-butoxysilane, diethoxydi-n-butoxysilane, monoethoxytri-n-butoxy Silane, triethoxymono-n-pentyloxysilane, diethoxydi-n-pentyloxysilane, monoethoxytri-n-pentyloxysilane, tri-n-propoxy mono-n-butoxysilane, di-n-propoxydi-n-butoxysilane, mono-n-propoxytri-n-propoxysilane, tri-n-propoxymono -n-pentyloxysilane, di-n-propoxydi-n-pentyloxysilane, mono-n-propoxytri-n-pentyloxysilane, tri-n-butoxy Mono-n-pentyloxysilane, di-n-butoxydi-n-pentyloxysilane, mono-n-butoxytri-n-pentyloxysilane, methyltrimethoxysilane , Methyltriethoxysilane, Methyltri-n-propoxysilane, Methyltris-n-propoxysilane, Methyltriethoxysilane, Methyltris-n-pentyl Oxysilane, Ethyltrimethoxysilane, Ethyltriethoxysilane, Ethyltri-n-propoxysilane, Ethyltri-n-butoxysilane, and Ethyltri-n-pentyl oxysilane. These hydrolyzable silane compounds (B) may be used individually by 1 type, and may be used in combination of 2 or more types. Moreover, the partial hydrolysis-condensation product of the said alkoxysilane compound can also be used as a hydrolyzable silane compound (B).

Among these, tetramethoxysilane, tetraethoxysilane Alkane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane are preferred, and tetramethoxysilane and tetraethoxysilane are particularly preferred .

As the hydrolyzable silane compound (B) having an isocyanate group, a compound represented by the following formula (b1) is preferable.

(R ^b1 ) _4-n Si(NCO) _n . . . (b1)

(In formula (b1), R ^b1 is a hydrocarbon group, and n is an integer of 3 or 4.)

The hydrocarbon group of R ^b1 in the formula (b1) is not particularly limited as long as the object of the present invention is not inhibited. R ^b1 is preferably an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 1 to 12 carbon atoms, or an aralkyl group having 1 to 12 carbon atoms.

Suitable examples of the aliphatic hydrocarbon group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl. base, n-pentyl, isopentyl, neopentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n - Decyl, n-undecyl, and n-dodecyl.

Suitable examples of the aromatic hydrocarbon group having 1 to 12 carbon atoms include a phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 2-ethylphenyl group, and a 3-methylphenyl group. -Ethylphenyl, 4-ethylphenyl, alpha-naphthyl, beta-naphthyl, and biphenyl.

Suitable examples of the aralkyl group having 1 to 12 carbon atoms include a benzyl group, a phenethyl group, a α-naphthylmethyl group, a β-naphthylmethyl group, a 2-α-naphthylethyl group, and a 2-α-naphthylethyl group. - β-Naphthylethyl.

Among the hydrocarbon groups described above, methyl and ethyl are preferred, and Methyl is more preferred.

Among the hydrolyzable silane compounds (B) represented by the formula (b1), tetraisocyanate silane, methyl triisocyanate silane, and ethyl triisocyanate silane are preferable, and tetraisocyanate silane is more preferable.

In addition, the hydrolyzable silane compound (B) having an isocyanate group and the hydrolyzable silane compound (B) having a linear or branched aliphatic alkoxy group having 1 to 5 carbon atoms can be used in combination. In this case, the ratio between the molar number X of the hydrolyzable silane compound (B) having an isocyanate group and the hydrolyzable silane compound (B) having a linear or branched aliphatic alkoxy group having 1 to 5 carbon atoms The ratio X/Y of the molar number Y is preferably 1/99~99/1, more preferably 50/50~95/5, particularly preferably 60/40~90/10.

When the diffusing agent composition contains the hydrolyzable silane compound (B), the content of the hydrolyzable silane compound (B) in the diffusing agent composition is not particularly limited, but the concentration of Si is preferably 0.001 to 3.0% by mass, 0.01-1.0 mass % is more preferable. When the diffusing agent composition contains the hydrolyzable silane compound (B) at such a concentration, the diffusion of the impurity diffusing component (A) from the outside of the thin coating film formed using the diffusing agent composition is easily suppressed, and the impurity is easily diffused. The components are well and uniformly diffused in the semiconductor substrate.

[Organic solvent (S)]

The diffusing agent composition can generally contain an organic solvent (S) as a solvent in order to form a thin coating film. The type of the organic solvent (S) is not particularly limited as long as the object of the present invention is not inhibited.

Furthermore, when the diffusing agent composition contains the hydrolyzable silane compound (B), it is preferable that the diffusing agent composition does not contain substantially water. The fact that water is not substantially contained in the diffusing agent composition means that the diffusing agent composition does not contain water in such an amount that the hydrolyzable silane compound (B) is hydrolyzed to such an extent that the desired effect of its addition cannot be obtained.

Specific examples of the organic solvent (S) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether. , propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol Monobutyl ether, diethylene glycol monophenyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monophenyl ether, tripropylene glycol Monoethers of glycols such as ethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tripropylene glycol monomethyl ether, and tripropylene glycol monoethyl ether; diisoamyl ether, diisobutyl ether Monoethers of ether, benzyl methyl ether, benzyl ethyl ether, dioxane, tetrahydrofuran, anisole, perfluoro-2-butyltetrahydrofuran, and perfluorotetrahydrofuran Class; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol Dipropyl ether, propylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, dipropylene glycol diethyl ether Chain diethers of glycols such as methyl ether, dipropylene glycol diethyl ether, dipropylene glycol dipropyl ether, and dipropylene glycol dibutyl ether; cyclic diethers such as 1,4-dioxane class; 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone ketone, 1-hexanone, 2-hexanone, 3-pentanone, diisobutyl ketone, cyclohexanone, methyl cyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, Ketones such as ethyl isobutyl ketone, acetyl acetone, acetone acetone, ionone, diacetone alcohol, acetyl methanol, acetophenone, methyl naphthyl ketone, and isophorone; Methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, ethylene glycol monomethyl ether acetate, Ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol mono Ethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate Esters, Diethylene Glycol Monoethyl Ether Acetate, Diethylene Glycol Monophenyl Ether Acetate, Diethylene Glycol Monobutyl Ether Acetate, 2-Methoxybutyl Acetate, 3-Methoxy Butyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether Acetate, Propylene Glycol Monoethyl Ether Acetate, Propylene Glycol Monopropyl Ether Acetate, 2-Ethoxybutyl Acetate, 4-Ethoxybutyl Acetate, 4-Propoxybutyl Acetate, 2 -Methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3 -Methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate Ester, Butyl Formate, Propyl Formate, Ethyl Carbonate, Propyl Carbonate, Butyl Carbonate, Methyl Pyruvate, Ethyl Pyruvate, Propyl Pyruvate, Butyl Pyruvate, Methyl Acetate ester, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate esters, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, and isopropyl-3-methoxypropionate, propylidene carbonate, and γ- Esters such as butyrolactone; N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoramide, and 1 , 3-dimethyl-2-tetrahydroimidazolone and other amide-based solvents without active hydrogen atoms; sulfene such as dimethyl sulfoxide; pentane, hexane, octane, decane, 2 , 2,4-trimethylpentane, 2,2,3-trimethylhexane, perfluorohexane, perfluoroheptane, limonene, and pinene and other aliphatic hydrocarbon solvents that may also contain halogens ;Benzene, toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene, ethyl Aromatic hydrocarbon solvents such as dimethylbenzene and dipropylbenzene; methanol, ethanol, n-propanol, isopropanol, butanol, isobutanol, 2-methoxyethanol, 2-ethoxy Monovalent alcohols such as ethanol, 3-methyl-3-methoxybutanol, hexanol, cyclohexanol, benzyl alcohol, and 2-phenoxyethanol; ethylene glycol, propylene glycol, diethylene glycol , and dipropylene glycol and other glycols. In addition, in the illustration of the said preferable organic solvent (S), the organic solvent containing an ether bond and an ester bond is classified into esters. These may be used alone or in combination of two or more.

When the diffusing agent composition contains the hydrolyzable silane compound (B), it is preferable to use the organic solvent (S) which does not have a functional group reactive with the hydrolyzable silane compound (B). Especially when the hydrolyzable silane compound (B) has an isocyanate group, it is preferable to use the organic solvent (S) which does not have a functional group which reacts with the hydrolyzable silane compound (B).

The functional group that reacts with the hydrolyzable silane compound (B) includes both a functional group that reacts directly with a group capable of generating a hydroxyl group by hydrolysis and a functional group that reacts with a hydroxyl group (silanol group) generated by hydrolysis. As a functional group which reacts with a hydrolyzable silane compound (B), a hydroxyl group, a carboxyl group, an amino group, a halogen atom, etc. are mentioned, for example.

As a suitable example of the organic solvent which does not have a functional group which reacts with the hydrolyzable silane compound (B), among the specific examples of the above-mentioned organic solvent (S), there are monoethers, chain diethers, and cyclic diethers. Ethers, ketones, esters, amide-based solvents that do not have active hydrogen atoms, sulfites, aliphatic hydrocarbon-based solvents that may also contain halogen, and organic solvents listed as specific examples of aromatic hydrocarbon-based solvents.

[other ingredients]

The diffusing agent composition may contain various additives such as surfactants, antifoaming agents, pH adjusters, viscosity adjusters, etc. within the range that does not hinder the purpose of the present invention. In addition, the diffusing agent composition may contain an adhesive resin for the purpose of improving coatability or film-forming properties. Various resins can be used as the adhesive resin, and an acrylic resin is preferable.

A diffusing agent composition is obtained by uniformly mixing the above-described components in a specific amount, respectively.

<<Manufacturing method of semiconductor substrate>>

The manufacturing method of a semiconductor substrate includes: forming a coating film by coating the above-mentioned diffusing agent composition, and, The diffusion of the impurity diffusion component (A) in the diffusing agent composition to the semiconductor substrate.

Hereinafter, the step of forming a coating film will be referred to as a "coating step", and the step of diffusing the impurity diffusion component (A) on the semiconductor substrate will be referred to as a "diffusion step". Hereinafter, the coating step and the diffusion step will be described in order.

[Coating step]

In the coating step, the diffusing agent composition is coated on the semiconductor substrate to form a coating film. Hereinafter, the coating step will be described in the order of the diffusing agent composition, the semiconductor substrate, and the coating method.

(Semiconductor substrate)

The semiconductor substrate is not particularly limited, and various substrates conventionally used for diffusing impurity diffusion components can be used. As the semiconductor substrate, typically a silicon substrate can be used. Since the impurity diffusion component contained in the diffusing agent composition contains boron, an n-type silicon substrate is suitably used as the silicon substrate.

Semiconductor substrates such as silicon substrates have a natural oxide film formed by natural oxidation of the surface of the semiconductor substrate. For example, there are many natural oxide films mainly composed of SiO ₂ on the silicon substrate.

When diffusing the impurity-diffusing components on the semiconductor substrate, a hydrofluoric acid aqueous solution or the like is typically used, and the natural oxide film on the surface of the semiconductor substrate is removed.

However, when the above-mentioned diffusing agent composition is used, the natural oxide film on the surface of the semiconductor substrate may or may not be removed.

When the natural oxide film on the surface of the semiconductor substrate is not removed, the impurity-diffused component tends to diffuse slightly better in the semiconductor substrate than when the natural oxide film is removed.

For example, when the natural oxide film on the surface of the silicon substrate is not removed, boron atoms (boron compounds) will be doped into the natural oxide film with a relatively low silicon density, and the surface layer of the semiconductor substrate will be doped with boron atoms (boron compounds) more efficiently. .

As a result, it is presumed that a thin film such as borosilicate glass is formed on the surface of the semiconductor substrate, and boron is well diffused in the semiconductor substrate.

The semiconductor substrate may also have a three-dimensional structure on the surface coated with the diffusing agent composition. According to the present invention, even if the semiconductor substrate has such a three-dimensional structure on its surface, especially a three-dimensional structure with nano-sized micro-patterns, the above-described diffusing agent composition can be applied to, for example, 30 nm on the semiconductor substrate. The thin coating film formed with the following film thickness allows the impurity-diffusion component to diffuse well and uniformly to the semiconductor substrate.

The shape of the pattern is not particularly limited, but typically, the cross-sectional shape is a rectangular straight line or a curved line or groove, or a hole shape.

When the semiconductor substrate has a pattern in which a plurality of parallel lines are repeatedly arranged as a three-dimensional structure, the width between the lines can be 1 μm or less, 100 nm or less, 60 nm or less, or 20 nm or less. As the height of the line, a height of 30 nm or more, 100 nm or more, 1 μm or more, or 5 μm or more can be applied.

(coating method)

The film thickness of the coating film formed using the diffusing agent composition is not particularly limited. The diffusing agent composition is coated on the semiconductor substrate so that the film thickness of the coating film formed using the diffusing agent composition is preferably 30 nm or less, and more preferably 0.2 to 10 nm.

The method of coating the diffusing agent composition is not particularly limited as long as a coating film having a desired thickness can be formed. As a coating method of the diffusing agent composition, a spin coating method, an ink jet method, and a spray method are preferable. In addition, the film thickness of a coating film is the average value of the film thickness of 5 points or more measured using an ellipsometry.

The thickness of the coating film is appropriately set in accordance with the shape of the semiconductor substrate or the degree of diffusion of the impurity diffusion component (A) set arbitrarily.

After the diffusing agent composition is coated on the surface of the semiconductor substrate, it is also preferable to rinse the surface of the semiconductor substrate with an organic solvent. After the coating film is formed, by washing the surface of the semiconductor substrate, the thickness of the coating film can be made more uniform. In particular, when the semiconductor substrate has a three-dimensional structure on its surface, the film thickness of the coating film at the bottom (step portion) of the three-dimensional structure tends to become thick. However, by rinsing the surface of the semiconductor substrate after the formation of the coating film, the thickness of the coating film can be made uniform.

As the organic solvent used for rinsing, the aforementioned organic solvent which may be contained in the diffusing agent composition can be used.

[diffusion step]

In the diffusion step, the impurity diffusion component (A) in the thin coating film formed on the semiconductor substrate using the diffusing agent composition is diffused to the semiconductor substrate plate. The method of diffusing the impurity-diffusing component (A) on the semiconductor substrate is not particularly limited as long as it is a method of diffusing the impurity-diffusing component (A) from the coating film of the diffusing agent composition by heating.

As a typical method, there is a method of heating a semiconductor substrate having a coating film of a diffusing agent composition in a heating furnace such as an electric furnace. At this time, the heating conditions are not particularly limited as long as the impurity diffusion component (A) is diffused to a desired degree.

Usually, after the organic matter in the coating film is removed by firing in an oxidizing gas atmosphere, the semiconductor substrate is heated in an inert gas atmosphere to diffuse the impurity-diffusing component (A) into the semiconductor substrate.

The heating during sintering the organic matter is preferably 300 to 1000°C, more preferably at a temperature of about 400 to 800°C, preferably for 1 to 120 minutes, and more preferably for 5 to 60 minutes.

The heating for diffusing the impurity-diffusing component (A) is preferably 700°C or higher and 1400°C or lower, more preferably 700°C or higher and lower than 1200°C, preferably for 1 to 120 minutes, and more preferably 5~60 minutes.

Since the diffusing agent composition containing the impurity-diffusing component (A) is used, the impurity-diffusing component (A) diffuses well in the semiconductor substrate even if the temperature during diffusion is low such as 1000° C. or lower.

In addition, in the typical composition of the present invention, since organic substances are unlikely to be contained, heating for firing can be omitted.

Furthermore, when the semiconductor substrate is rapidly heated to a specific diffusion temperature at a temperature increase rate of 25°C/sec or more, the holding time of the diffusion temperature may be as short as 30 seconds or less, 10 seconds or less, or less than 1 second. between. In this case, the impurity diffusion component (A) is easily diffused at a high concentration in a shallow region on the surface of the semiconductor substrate.

By the method described above, even if a semiconductor substrate having a three-dimensional structure having nano-scale microscopic voids on its surface is used, it is possible to suppress the occurrence of defects in the semiconductor substrate, and at the same time, the impurity diffusion components can be diffused well and uniformly. on semiconductor substrates.

Therefore, the method related to the present invention can be suitably applied to the manufacture of a multi-gate device having a tiny and three-dimensional structure. Since the method related to the present invention can suppress the occurrence of defects in the semiconductor substrate during the diffusion of impurity diffusion components, it can be suitably applied to semiconductor elements such as CMOS elements of CMOS image sensors or logic LSI devices in particular. manufacture.

[Example]

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

[Example 1 and Comparative Example 1]

In Example 1, the following compound A1 was used as an impurity diffusion component ((A) component). In Comparative Example 1, the following compound A2 (triethylamine borane) was used as the component (A). In Comparative Example 2, the following compound A3 (nadolborane) was used as the component (A). In Comparative Example 3, the following compound A4 (trimethyl borate) was used as the component (A).

The said (A) component was each melt|dissolved in butyl acetate, and the density|concentration became 0.5 mass %, and the diffusing agent composition of Example 1 and Comparative Examples 1-3 was obtained.

The diffusing agent compositions of Example 1 and Comparative Examples 1 to 3 were respectively coated on the surface of a silicon substrate (6 inches, n-type) with a flat surface using a spin coater to form a coating film with the thickness described in Table 1. As a silicon substrate, a substrate from which the natural oxide film on the surface was removed by being immersed in a hydrofluoric acid aqueous solution having a concentration of 0.5 mass % was used.

After the formation of the coating film, the diffusion treatment of the impurity-diffused component is performed according to the following method.

Using a rapid annealing treatment device (lamp annealing device), in a nitrogen atmosphere with a flow rate of 1 L/m, heating was performed at a temperature increase rate of 25°C/sec, and diffusion was performed at the diffusion temperature and diffusion time described in Table 1 for 1 second. deal with. The starting point of the diffusion time is the point when the temperature of the substrate reaches a specific diffusion temperature. After the diffusion is completed, the semiconductor substrate is rapidly cooled to room temperature.

As a result of the diffusion treatment of the impurity-diffused components, it is confirmed whether the semiconductor substrate is inverted from n-type to p-type. When it was reversed, it was evaluated as ○, and when it was not reversed, it was evaluated as ×, and the evaluation results are described in Table 1.

In addition, since the diffusion test of 1200 degreeC was performed sequentially, the diffusion test of the temperature lower than the temperature evaluated as x evaluation from the beginning was not performed.

As can be seen from Table 1, the substrate surface has a structure that is easily adsorbed, and in Example 1 in which the (A) component that can form a diffusion layer with a thickness of several nm by coating on the surface of the semiconductor substrate, even at 1100 The (A) component is also favorably diffused in the semiconductor substrate at degrees C or lower.

In addition, regarding Example 1, the sheet resistance value of the semiconductor substrate subjected to diffusion treatment at 1200°C was 593 (Ω/sq.), and the sheet resistance value of the semiconductor substrate subjected to diffusion treatment at 1100°C was 682 (Ω/sq. .), the sheet resistance value of the semiconductor substrate subjected to diffusion treatment at 1000°C was 1552 (Ω/sq.), and the sheet resistance value of the semiconductor substrate subjected to diffusion treatment at 900°C was 50447 (Ω/sq.).

On the other hand, from Comparative Example 1, it can be seen that only films can be formed in Comparative Examples 1 to 3 in which the component (A) of the structure in which boron atoms are in a tetravalent state or does not contain nitrogen atoms and is hardly adsorbed on the surface of the substrate is used. In an extremely thin film with a thickness of 0.2 nm or less, at a temperature of 1100° C. or less, the (A) component cannot be diffused well on the surface of the semiconductor substrate.

[Example 2]

In Example 2, the following compound A5 was used as an impurity diffusion component ((A) component).

The said (A) component was melt|dissolved in butyl acetate, and the density|concentration became 0.5 mass %, and the diffusing agent composition of Example 2 was obtained.

Using a spin coater, the diffusing agent composition of Example 2 was coated on the surface of a silicon substrate (6 inches, n-type) with a flat surface and rinsed with butyl acetate to form a coating film with a thickness of 1.7 nm. As a silicon substrate, a substrate from which the natural oxide film on the surface was removed by being immersed in a hydrofluoric acid aqueous solution having a concentration of 0.5 mass % was used.

After the formation of the coating film, in the same manner as in Example 1, diffusion treatment of impurity diffusion components at diffusion temperatures of 1000°C and 1100°C was performed.

As a result, the sheet resistance value of the semiconductor substrate subjected to diffusion treatment at 1000°C was 9699 (Ω/sq.), and the sheet resistance value of the semiconductor substrate subjected to diffusion treatment at 1100°C was 1748 (Ω/sq.).

From these results, it can be seen that when the diffusing agent composition of Example 2 is used, the component (A) diffuses well at a diffusion temperature of 1100° C. or lower.

[Example 3]

In Example 3, the following compound A6 was used as the impurity diffusion component ((A) component).

The said (A) component was melt|dissolved in butyl acetate, and the density|concentration became 0.5 mass %, and the diffusing agent composition of Example 3 was obtained.

The diffusing agent composition of Example 3 was coated on the surface of a silicon substrate (6 inches, n-type) with a flat surface using a spin coater to form a coating film with a thickness of 27 nm. As a silicon substrate, a substrate from which the natural oxide film on the surface was removed by being immersed in a hydrofluoric acid aqueous solution having a concentration of 0.5 mass % was used.

After the formation of the coating film, in the same manner as in Example 1, diffusion treatment of impurity diffusion components at diffusion temperatures of 900°C, 1000°C, and 1100°C was performed.

As a result, the sheet resistance value of the semiconductor substrate subjected to the diffusion treatment at 900°C was 7338 (Ω/sq.), and the sheet resistance value of the semiconductor substrate subjected to the diffusion treatment at 1000°C was 1075 (Ω/sq.), in The sheet resistance value of the semiconductor substrate subjected to diffusion treatment at 1100° C. was 596 (Ω/sq.).

From these results, it can be seen that when the diffusing agent composition of Example 3 is used, the component (A) diffuses well at a diffusion temperature of 1100° C. or lower.

[Examples 4 to 11]

In Examples 4 to 11, the following compounds A7 to A13 were used as impurities to expand Dispersed component ((A) component) is used.

The (A) component of the kind described in Table 2 was dissolved in the solvent of the kind described in Table 2, respectively, and the concentration was 0.5 mass %, and the diffusing agent composition of Examples 4-11 was obtained.

The diffusing agent compositions of Examples 4 to 11 were respectively coated on the surface of a silicon substrate (6 inches, n-type) with a flat surface using a spin coater to form a coating film with the film thickness described in Table 2. As a silicon substrate, a substrate from which the natural oxide film on the surface was removed by being immersed in a hydrofluoric acid aqueous solution having a concentration of 0.5 mass % was used.

In addition, about Example 11, it rinsed with butyl acetate after coating.

After the formation of the coating film, in the same manner as in Example 1, a diffusion treatment of impurity diffusion components at a diffusion temperature of 1000° C. was performed.

In any embodiment, after the diffusion process, the semiconductor substrate is inverted from n-type to p-type. The results of measuring the sheet resistance value of the semiconductor substrate after the diffusion treatment are shown in Table 2.

From Table 2, it can be seen that the substrate surface has a structure that is easy to adsorb, and in Examples 4 to 11 using the (A) component that can form a diffusion layer by coating on the surface of the semiconductor substrate, (A) ) components diffuse into the semiconductor substrate.

[Example 12]

The said compound A1 was used as (A) component. (A) component was melt|dissolved in butyl acetate, and the density|concentration became 1.0 mass %, and the diffusing agent composition was obtained.

Next, the diffusing agent composition was coated on the surface of a silicon substrate (n-type) having a plurality of grooves with a width of 500 nm and a depth of 2.8 μm using a spin coater to form a coating film. As a silicon substrate, a substrate from which the natural oxide film on the surface was removed by being immersed in a hydrofluoric acid aqueous solution having a concentration of 0.5 mass % was used.

After coating, rinse with butyl acetate.

The relevant coating operation was repeated 10 times to form a coating film with a thickness of 17.4 nm. In addition, the repeated coating was performed 10 times in order to make it easier to observe the formation state of the coating film.

The cross-section of the semiconductor substrate after the coating film is formed Microscopic observation revealed that a coating film was formed almost uniformly on the front surface of the inner surface of the recess (groove).

Next, using a rapid annealing treatment apparatus (lamp annealing apparatus), heating was performed in a nitrogen atmosphere with a flow rate of 1 L/m at a temperature increase rate of 25° C./sec, and a diffusion treatment was performed at a diffusion temperature of 1100° C. and a diffusion time of 10 seconds. The starting point of the diffusion time is the point when the temperature of the substrate reaches a specific diffusion temperature. After the diffusion is completed, the semiconductor substrate is rapidly cooled to room temperature.

The surface of the semiconductor substrate after the diffusion treatment was observed by scanning electrostatic capacitance microscopy (SCM method) to confirm the carrier distribution on the surface of the semiconductor substrate.

[Example 13]

The said compound A1 was used as (A) component. (A) component was melt|dissolved in butyl acetate, and the density|concentration became 1.0 mass %, and the diffusing agent composition was obtained.

Next, the diffusing agent composition was coated on the surface of the SiN-coated substrate having a plurality of grooves with a width of 80 nm and a depth of 200 nm using a spin coater, and rinsed with butyl acetate.

When the cross section of the semiconductor substrate after the coating film was formed was observed with an electron microscope, it was found that the coating film was formed almost uniformly on the inner surface of the recess (groove).

[Examples 14 to 25]

The aforementioned compound A1 and the hydrolyzable silane compound (B) ((B) (part, alkoxysilane compound) were dissolved in butyl acetate, respectively, so that the concentration described in Table 3 was obtained, and the diffusing agent compositions of Examples 14 to 25 were obtained.

The (B) component described in Table 3 is as follows.

B1: Methyltriethoxysilane

B2: Dimethyldimethoxysilane

B3: Phenyltriethoxysilane

Using a spin coater, the diffusing agent compositions of Examples 14 to 25 were coated on the surface of a silicon substrate (6 inches, n-type) with a flat surface, and then rinsed with butyl acetate to form the coating with the film thickness described in Table 3. membrane. As the silicon substrate, a substrate from which the natural oxide film on the surface was removed by being immersed in an aqueous solution of hydrofluoric acid having a concentration of 0.5 mass % was used.

After the formation of the coating film, in the same manner as in Example 1, a diffusion treatment of impurity diffusion components at a diffusion temperature of 1000° C. was performed.

In any embodiment, after the diffusion process, the semiconductor substrate is inverted from n-type to p-type. The results of measuring the sheet resistance value of the semiconductor substrate after the diffusion treatment are shown in Table 3.

From Examples 14 to 25, it can be seen that when a diffusing agent composition containing component (A) that can form a diffusion layer by coating the surface of the semiconductor substrate with a structure that is easily adsorbed on the surface of the semiconductor substrate is used, the diffusing agent composition even contains The hydrolyzable silane compound (B) can satisfactorily diffuse the (A) component to the semiconductor substrate even at 1000°C.

[Example 26, Example 27]

In Example 26 and Example 27, the aforementioned compound A1 was used as an impurity diffusion component ((A) component). (A) component was melt|dissolved in butyl acetate, and the liquid which made the density|concentration 1.0 mass % was used as a diffusing agent composition in Example 26 and Example 27.

The diffusing agent composition was coated on the surface of a silicon substrate (6 inches, n-type) with a flat surface using a spin coater, and then rinsed with dibutyl ether to form a coating film with a thickness of 3.0 nm.

In Example 26, a silicon substrate with a natural oxide film on its surface was directly used. In Example 27, as a silicon substrate, a substrate from which the natural oxide film on the surface was removed by being immersed in an aqueous solution of hydrofluoric acid having a concentration of 0.5 mass % was used.

After the formation of the coating film, the diffusion treatment of the impurity-diffused component is performed according to the following method.

Using a rapid annealing device (lamp annealing device), heating was performed at a temperature increase rate of 15° C./sec in a nitrogen atmosphere with a flow rate of 1 L/m, and a diffusion treatment was performed at a diffusion temperature of 950° C. and a diffusion time of 25 seconds. The starting point of the diffusion time is the point when the temperature of the substrate reaches a specific diffusion temperature. After the diffusion is completed, the semiconductor substrate is rapidly cooled to room temperature.

In any one of Example 26 and Example 27, the semiconductor substrate is inverted from n-type to p-type after the diffusion process. The results of measuring the sheet resistance value of the semiconductor substrate after the diffusion treatment are shown in Table 4.

It can be seen from Example 26 and Example 27 that the impurity diffusion components can be well diffused in the silicon substrate regardless of whether the natural oxide film on the surface of the silicon substrate is removed or not.

Moreover, from the comparison between Example 26 and Example 27, it can be known that the silicon substrate is removed When there is a natural oxide film on the surface, it is easier to diffuse the impurity diffusion component well than when the natural oxide film is not removed.

Claims (8)

A diffusing agent composition, which is a diffusing agent composition for impurity diffusion on a semiconductor substrate, and includes an impurity diffusing component (A), the impurity diffusing component (A) can be formed by coating on the surface of the semiconductor substrate The diffusion layer is a boron compound containing nitrogen atoms, and the boron compound is represented by the following formula (a1), the following formula (a2), the following formula (a2-3) or the following formula (a2-5) compound,

(In formula (a1), R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, a hydroxyl group, an organic group containing no nitrogen atom, or a group containing a nitrogen atom, and R ¹ , R ² , R ³ and At least one of R ⁴ is a nitrogen atom-containing group, R ¹ and R ² , R ² and R ⁴ , R ³ and R ⁴ , and R ¹ and R ³ can also be independently bonded to each other to form a ring, formula (a2) wherein, R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, a hydroxyl group, an organic group containing no nitrogen atom, or a group containing a nitrogen atom, and at least one of R ⁵ , R ⁶ and R ⁷ is a nitrogen atom-containing group group, and two of R ⁵ , R ⁶ and R ⁷ are bonded to each other to form a ring, or at least one of R ⁵ , R ⁶ and R ⁷ is a group represented by -R ^a1 or -OR ^a1 (R ^a1 is A hydrocarbon group that may also have a substituent, or a heterocyclic group that may also have a substituent), in formula (a2-3), R ³⁸ is a nitrogen-containing heterocyclic group, or a nitrogen-containing group substituted by a nitrogen-containing group that does not contain a nitrogen atom R ³⁹ and R ⁴⁰ are independently a hydrogen atom, an aliphatic hydrocarbon group with 1 to 10 carbon atoms, an aromatic hydrocarbon group with 6 to 10 carbon atoms, an aralkyl group with 7 to 12 carbon atoms, a carbon An aliphatic alkyl group having 2 to 10 atoms, or an aromatic alkyl group having 7 to 11 carbon atoms, R ³⁹ and R ⁴⁰ can also be bonded to each other to form a ring. In formula (a2-5), R ⁴⁶ to R ⁵¹ Each independently is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an aliphatic acyl group having 2 to 10 carbon atoms. , or an aromatic aryl group having 7 to 11 carbon atoms, R ⁴⁶ and R ⁴⁷ , R ⁴⁸ and R ⁴⁹ , and R ⁵⁰ and R ⁵¹ are each independently bonded to each other to form a ring). The diffusing agent composition according to claim 1, which contains an organic solvent (S). A method of manufacturing a semiconductor substrate, comprising: forming a coating film by applying the diffusing agent composition as claimed in claim 1 on the semiconductor substrate, and diffusing the impurity-diffusing component (A) in the diffusing agent composition to the semiconductor substrate. diffusion. The method for producing a semiconductor substrate according to claim 3, wherein the coating film is heated at a temperature of 900° C. or more and less than 1,200° C. to diffuse the impurity-diffusing component (A) in the semiconductor substrate. The method for manufacturing a semiconductor substrate according to claim 3 or 4, wherein the aforementioned The film thickness of the coating film is 30 nm or less. The method for producing a semiconductor substrate according to claim 5, wherein the film thickness of the coating film is 0.2 to 10 nm. The method for producing a semiconductor substrate according to claim 3 or 4, wherein the semiconductor substrate has a three-dimensional structure on a surface on which the diffusing agent composition is applied, and the three-dimensional structure includes a convex portion and a concave portion. The manufacturing method of the semiconductor substrate of Claim 3 or 4 which comprises washing with the organic solvent of the said coating film.