TW201709284A - Diffusion agent composition - Google Patents

Abstract

A diffusion agent composition that, even when coated on a semiconductor substrate in a nano-scale thickness, allows an impurity diffusion component to be well diffused into the semiconductor substrate. The diffusion agent composition includes an impurity diffusion component and a silicon compound represented by R4-nSi(NCO)n in which R represents a hydrocarbon group and n is an integer of 3 or 4, the silicon compound is capable of being hydrolyzed to produce a silanol group, and the water content of the diffusion agent composition is not more than 0.05% by mass.

Description

Diffusion agent composition

The present invention relates to a diffusing agent composition comprising an impurity-diffusing component and a hydrolyzable decane compound having a predetermined structure.

It is produced by diffusing an impurity diffusion component such as phosphorus or boron onto a semiconductor substrate using a semiconductor substrate of a semiconductor element such as a transistor, a diode, or a solar cell.

As a method for producing such a semiconductor substrate, for example, after an impurity diffusion component containing an organic phosphorus compound, a thickening polymer, an organic solvent, and a water diffusing agent composition are applied onto a semiconductor substrate, At a temperature of more than 1000 ° C, for example, a method in which the impurity diffusion component is diffused on the semiconductor substrate by heating for 10 hours is used (see Patent Document 1).

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-347306

The semiconductor substrate has a three-dimensional three-dimensional structure on its surface. Examples of the three-dimensional three-dimensional structure include a fin having a plurality of source electrodes, a fin having a plurality of drain electrodes, and a gate perpendicular to the fins for forming a Fin-FET. A three-dimensional structure of a nano-scale like a three-dimensional structure of a multi-gate element.

In this case, in order to uniformly diffuse the impurity-diffusing component from the surface of the semiconductor substrate from the coating film of the diffusing agent composition, it is desirable to form a coating film having a uniform film thickness even on the surface of the side wall of the concave portion of the three-dimensional structure. Therefore, it is necessary to uniformly apply the diffusing agent composition to the entire surface of the substrate at a film thickness of a nanometer order, and to diffuse the impurity diffusion component well from the formed thin coating film.

However, as disclosed in Patent Document 1, it is difficult to uniformly apply a diffusing agent composition to a surface of a semiconductor substrate at a film thickness of a nanometer in a diffusing agent composition containing a tackifying polymer.

Moreover, when the diffusing agent composition disclosed in Patent Document 1 is used, even if the diffusing agent composition can be applied thinly on the surface of the semiconductor substrate, it is difficult to make the impurity diffusing component diffuse well due to the composition of the diffusing agent composition.

The present invention has been made in view of the above problems, and it is possible to provide a method in which a diffusing agent composition is applied to a semiconductor substrate at a film thickness of a nanometer, and the impurity diffusing component can be diffused in the semiconductor substrate. The diffusing agent composition serves as an object.

The present inventors have discovered that by using a diffusing agent composition The impurity-diffusing component (A) and the Si compound (B) having a predetermined structure of an isocyanate group have a water content of the diffusing agent composition of 0.05% by mass or less, and the above problems can be solved, and the present invention has been completed.

Specifically, the present invention relates to a diffusing agent composition for diffusing impurities of a semiconductor substrate, characterized by comprising an impurity diffusing component (A) and a Si compound (B) represented by the following formula (1), the Si compound (B) can be hydrolyzed to form a sterol group, R _4-n Si(NCO) _n . . . (1)

(In the formula (1), R is a hydrocarbon group, n is an integer of 3 or 4), and the moisture content in the diffusing agent composition is 0.05% by mass or less.

According to the present invention, it is possible to provide a diffusing agent composition in which the impurity-diffusing component is well diffused in the semiconductor substrate even when the diffusing agent composition is applied to the semiconductor substrate in a film thickness of a nanometer.

≪Diffusion agent composition≫

The diffusing agent composition contains an impurity diffusing component (A) and a Si compound (B) which can be hydrolyzed to form a sterol group. In the present specification, the Si compound (B) which can form a sterol group is also referred to as a hydrolyzable decane compound (B). Hereinafter, a method of preparing a diffusing agent composition, a necessary or optional component, and a method of preparing a diffusing agent composition will be described.

[impurity diffusion component (A)]

The impurity-diffusing component (A) is not particularly limited as long as it is used for doping a semiconductor substrate, and may be an n-type dopant or a p-type dopant. Examples of the n-type dopant include a simple substance such as phosphorus, arsenic, and antimony, and a compound containing these elements. Examples of the p-type dopant include a simple substance such as boron, gallium, indium, and aluminum, and a compound containing these elements.

The impurity-diffusing component (A) is preferably a phosphorus compound, a boron compound, or an arsenic compound because of ease of availability or ease of handling. Preferred examples of the phosphorus compound include phosphoric acid, phosphorous acid, diphosphoric acid, polyphosphoric acid, and phosphorus pentoxide or phosphites, phosphates, phosphite (trialkyldecyl), and phosphoric acid. (trialkyldecylalkyl) and the like. Preferred examples of the boron compound include boric acid, metaboric acid, borous acid, perboric acid, hypoboric acid, and boron trioxide or trialkyl borate. Preferred examples of the arsenic compound include arsenic acid and trialkyl arsenate.

The phosphorus compound is preferably a phosphite, a phosphate, a phosphite (trialkylsulfanyl), or a phosphoric acid (trialkylsulfanyl), of which trimethyl phosphate and phosphoric acid are preferred. Ethyl ester, trimethyl phosphite, triethyl phosphite, phosphite (trimethoxydecyl), and phosphite (trimethoxydecyl), more preferably trimethyl phosphate, trimethyl phosphite And phosphite (trimethyl decyl), particularly preferably trimethyl phosphate.

As the boron compound, trimethylboron or triethyl is preferred. Boron, trimethyl borate, and triethyl borate.

As the arsenic compound, arsenic acid, triethoxy arsenic, and tri-n-butoxy arsenic are preferable.

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 used as a doping in a semiconductor substrate such as phosphorus, arsenic, antimony, boron, gallium, indium, or aluminum contained in the impurity-diffusing component (A). The amount of the element (mol) which is a function of the agent is 0.01 to 5 times the number of moles of Si contained in the hydrolyzable decane compound (B), and more preferably 0.05 to 3 times.

[hydrolyzable decane compound (B)]

The diffusing agent composition contains a hydrolyzable decane compound (B). The hydrolyzable decane compound (B) is a compound represented by the following formula (1), R _4-n Si(NCO) _n . . . (1)

(In the formula (1), R is a hydrocarbon group, and n is an integer of 3 or 4).

Therefore, when the diffusing agent composition of the present invention is applied to a semiconductor substrate to form a thin film, the hydrolyzable decane compound is mainly hydrolyzed and condensed by moisture in the environment of the coating environment to form a cerium oxide-based electrode in the coating film. Thin film.

The hydrocarbon group of R in the formula (1) is not particularly limited insofar as it does not inhibit the object of the present invention. R 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 a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group. Base, n-pentyl, isopentyl, neopentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-cycloheptyl, n-octyl, n-cyclooctyl, n- Anthracenyl, n-fluorenyl, 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 3 Ethylphenyl, 4-ethylphenyl, α-naphthyl, β-naphthyl, and biphenyl.

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

Among the hydrocarbon groups described above, a methyl group or an ethyl group is preferred, and a methyl group is more preferred.

Among the hydrolyzable decane compounds (B) represented by the formula (1), tetraisocyanate decane, methyl triisocyanate decane, and ethyl triisocyanate decane are preferable, and tetraisocyanate decane is more preferable.

The content of the hydrolyzable decane compound (B) in the diffusing agent composition is preferably 0.001 to 3.0% by mass, and more preferably 0.01 to 1.0% by mass, based on the concentration of Si. By containing the hydrolyzable decane compound (B) at such a concentration, the diffusing agent composition can suppress the external diffusion of the impurity-diffusing component (A) from the thin coating film formed using the diffusing agent composition, and can be suppressed. The impurity diffusion component is well diffused on the semiconductor substrate.

[Organic Solvent (S)]

The diffusing agent composition usually contains an organic solvent (S) as a solvent in a manner of forming a coating film of a film. The type of the organic solvent (S) is not particularly limited insofar as it does not inhibit the object of the present invention.

Further, since the diffusing agent composition contains the hydrolyzable decane compound (B), it is preferable to contain no water substantially. The diffusing agent composition does not substantially contain water, and means that the diffusing agent composition does not contain water which hydrolyzes the hydrolyzable decane compound (B) to such an extent that the object of the present invention is inhibited.

Specific examples of the organic solvent (S) include an anthracene such as dimethyl hydrazine; dimethyl hydrazine, diethyl hydrazine, bis(2-hydroxyethyl) fluorene, tetramethylene hydrazine or the like. Terpenes; N,N-dimethylformamide, N-methylformamide, N,N-dimethylacetamide, N-methylacetamide, N,N-diethylacetamidine Amines such as amines; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, N-hydroxyethyl- Indoleamines such as 2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl-2-imidazole Imidazolinones such as ketones; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, triethylene glycol (poly)alkylene glycol dialkyl ethers such as glyceryl ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, (poly)alkylene glycol alkyl ether acetates such as diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, etc.; tetrahydrofuran and the like Other ethers; methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone and other ketones; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl lactate An alkyl lactate such as acetate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, Ethyl ethoxyacetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, Ethyl acetate, n-propyl acetate, -i-propyl acetate, n-butyl acetate, -i-butyl acetate, n-amyl formate, i-amyl acetate, propionate-n -butyl ester, ethyl butyrate, n-propyl butyrate, -i-propyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate , other esters such as ethyl acetate, ethyl acetate, ethyl 2-oxybutyrate; lactones such as β-propiolactone, γ-butyrolactone, and δ-valerolactone; -hexane, n-heptane, n-octane, n-decane, methyloctane, n-decane, n-undecane, n-dodecane, 2,2,4,6,6 - linear, branched, or cyclic, pentamethylheptane, 2,2,4,4,6,8,8-heptamethylnonane, cyclohexane, methylcyclohexane, etc. Hydrocarbons; aromatic hydrocarbons such as benzene, toluene, naphthalene, 1,3,5-trimethylbenzene; p-menthane, diphenyl Dutch alkoxy, limonene, terpinene, bornane, norbornane, pinane etc. terpenes. These organic solvents may be used alone or in combination of two or more.

The diffusing agent composition contains a hydrolyzable decane compound (B), and the organic solvent (S) is preferably one which does not have a functional group which reacts with the hydrolyzable decane compound (B). In particular, in the case where the hydrolyzable decane compound (B) has an isocyanate group, it is preferred to use an organic solvent (S) which does not have a functional group reactive with the hydrolyzable decane compound (B).

The functional group reactive with the hydrolyzable decane compound (B) includes both a functional group directly reactive with a group capable of undergoing hydrolysis to form a hydroxyl group, and a functional group reactive with a hydroxyl group (sterol group) produced by hydrolysis. . Examples of the functional group reactive with the hydrolyzable decane compound (B) include a hydroxyl group, a carboxyl group, an amine group, and a halogen atom.

A suitable example of the organic solvent which does not have a functional group which reacts with the hydrolyzable decane compound (B) is a monoether, a chain diether, and a ring in the specific example of the above-mentioned organic solvent (S). An organic solvent exemplified as a specific example of a diether, a ketone, an ester, a guanamine solvent having no active hydrogen atom, an anthraquinone, an aliphatic hydrocarbon solvent which can contain a halogen, and an aromatic hydrocarbon solvent.

[Other ingredients]

The diffusing agent composition may include various additives such as a surfactant, an antifoaming agent, a pH adjuster, and a viscosity adjusting agent insofar as it does not inhibit the object of the present invention. Further, the diffusing agent composition may contain a binder resin for the purpose of improving coatability or film forming properties. As the binder resin, various resins can be used, and an acrylic resin is preferable.

[Modulation method of diffusing agent composition]

The diffusing agent composition can be prepared by mixing the above-mentioned necessary or optional components into a homogeneous solution. In the preparation of the diffusing agent composition, the impurity-diffusing component (A) or the hydrolyzable decane compound (B) can be used as a solution previously dissolved in the organic solvent (S). The diffusing agent composition can also be filtered by a desired opening diameter filter if necessary. The insoluble impurities are removed by the filtration treatment.

Also, as described above, the diffusing agent composition does not substantially contain water. Specifically, the moisture content of the diffusing agent composition is 0.05% by mass or less, preferably 0.015% by mass or less. When the moisture content of the diffusing agent composition is reduced to such a range, the impurity-diffusing component (A) is easily diffused particularly well in the semiconductor substrate.

The moisture content of the diffusing agent composition can be determined by the Karl Fischer method.

Further, the measurement of the moisture content in the diffusing agent composition is a case where the composition ratio of the organic solvent (S) in the diffusing agent composition is 99% or more, and the amount of water in the organic solvent (S) can be measured by substitution.

When the amount of water in the organic solvent (S) is from 0.045 to 0.055% by mass, it is preferred to measure the amount of water in the diffusing agent composition without substituting the amount of water of the organic solvent (S).

The method of reducing the moisture content of the diffusing agent composition is not particularly limited. As a method of reducing the water content, a method using a dehydrating agent such as a molecular sieve, magnesium sulfate anhydride, or sodium thiocyanate, or a distillation method can be mentioned. The treatment for reducing the moisture content may be carried out on the prepared diffusing agent composition, or in the organic solvent (S) or the organic solvent (S) solution of the impurity diffusing component (A) or the hydrolyzable decane compound (B).

≪Method of manufacturing semiconductor substrate≫

Hereinafter, a method of manufacturing a semiconductor substrate using the above-described diffusing agent composition will be described.

As a suitable manufacturing method of a semiconductor substrate, a film containing a coating diffusing agent composition on a semiconductor substrate to form a film of 30 nm or less is exemplified. A coating step of a thick coating film and a diffusion step of diffusing the impurity diffusion component (A) in the diffusing agent composition onto the semiconductor substrate. Hereinafter, the coating step and the diffusion step will be described.

<Coating step>

The semiconductor substrate is not particularly limited to use various substrates which have been conventionally used as targets for diffusing impurity diffusion components. As the semiconductor substrate, a germanium substrate is usually used.

The semiconductor substrate can have a three-dimensional structure on the surface on which the diffusing agent composition is applied. According to the present invention, the semiconductor substrate has a three-dimensional structure on its surface, in particular, a three-dimensional structure having a nano-scale micro-pattern, and the diffusing agent composition described above is made to have a film thickness of 30 nm or less. The thin coating film formed by the coating is formed on the semiconductor substrate, and the impurity diffusion component can be uniformly and uniformly diffused to the semiconductor substrate.

Although the shape of the pattern is not particularly limited, in general, the shape of the cross section is a rectangular straight line or a curved line or groove, or a hole shape formed by removing a column or a corner column.

When the semiconductor substrate has a three-dimensional structure and has a pattern in which a plurality of parallel lines are repeatedly arranged, a width of 60 nm or less, 40 nm or less, or 20 nm or less can be applied as the width between the lines. As the height of the wire, a height of 30 nm or more, 50 nm or more, or 100 nm or more can be applied.

The diffusing agent composition is applied to the semiconductor substrate so that the thickness of the coating film formed using the diffusing agent composition is 30 nm or less, preferably 0.2 to 10 nm. The method of applying the diffusing agent composition is not particularly limited as long as it is a coating film capable of forming a desired film thickness. As a coating method of a diffusing agent composition, a spin coating method, an inkjet method, and a spray method are preferable. Further, the film thickness of the coating film is an average value of film thicknesses of 5 or more points measured by an ellipsometer.

The film thickness of the coating film is appropriately set to any film thickness of 30 nm or less depending on the shape of the semiconductor substrate or the diffusion degree of the impurity diffusion component (A) which is arbitrarily set.

After the diffusing agent composition is applied onto the surface of the semiconductor substrate, the surface of the semiconductor substrate is preferably washed with an organic solvent. The film thickness of the coating film can be made more uniform by cleaning the surface of the semiconductor substrate after the formation of the coating film. In particular, in the case where the semiconductor substrate has a three-dimensional structure on the surface thereof, the film thickness of the coating film at the bottom portion (segment portion) of the three-dimensional structure is likely to be thick. However, the film thickness of the coating film can be made uniform by cleaning the surface of the semiconductor substrate after the formation of the coating film.

As the organic solvent used for the cleaning, the aforementioned organic solvent which the diffusing agent composition can contain can be used.

≪Diffusion step≫

In the diffusion step, the impurity diffusion component (A) in the thin coating film formed on the semiconductor substrate by the diffusing agent composition is diffused to the semiconductor substrate. Dispersing the impurity diffusion component (A) on the semiconductor substrate The method is a method of diffusing the diffusion component (A) by heating a coating film composed of a diffusing agent composition, and is not particularly limited.

A method of heating a semiconductor substrate including a coating film composed of a diffusing agent composition in a heating furnace such as an electric furnace is exemplified. At this time, the heating conditions are not particularly limited as long as the impurity diffusion component is diffused to a desired extent.

Usually, after the organic substance 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 diffusion component into the semiconductor substrate.

The heating at the time of firing the organic substance is preferably from 300 to 1000 ° C, more preferably from about 400 to 800 ° C, more preferably from 1 to 120 minutes, more preferably from 5 to 60 minutes.

The heating for diffusing the impurity-diffusing component is preferably from 800 to 1400 ° C, more preferably from 800 to 1200 ° C, more preferably from 1 to 120 minutes, more preferably from 5 to 60 minutes.

Further, the heating when the impurity-diffusing component (A) is diffused on the semiconductor substrate can be carried out by one or more methods selected from the group consisting of a lamp annealing method, a laser annealing method, and a microwave irradiation method.

As the lamp annealing method, a rapid thermal annealing method or a flash lamp annealing method can be cited.

The rapid thermal annealing method refers to heating the surface of a semiconductor substrate coated with a diffusing agent composition to a predetermined diffusion temperature by heating at a high temperature by a lamp, and secondly, maintaining a predetermined diffusion temperature for a short period of time. A method of rapidly cooling the surface of a semiconductor substrate.

The flash lamp annealing method is a heat treatment method in which a surface of a semiconductor substrate on which a diffusing agent composition is applied is heated to a predetermined diffusion temperature in a short time by irradiating a surface of a semiconductor substrate with a xenon flash lamp or the like.

The laser annealing method refers to a heat treatment method in which only the surface of the semiconductor substrate on which the diffusing agent composition is applied is heated to a predetermined diffusion temperature in a very short time by irradiating various laser beams on the surface of the semiconductor substrate.

The microwave irradiation method refers to a heat treatment method in which only the surface of the semiconductor substrate on which the diffusing agent composition is applied is heated to a predetermined diffusion temperature in a very short time by irradiating microwaves on the surface of the semiconductor substrate.

When a lamp annealing method, a laser annealing method, a microwave irradiation method, or the like is used, the diffusion temperature when the impurity diffusion component is diffused is preferably 600 to 1400 ° C, more preferably 800 to 1200 ° C. After the temperature of the surface of the substrate reaches the diffusion temperature, the diffusion temperature can be maintained for a desired period of time. The time for maintaining the predetermined diffusion temperature is as short as possible in the range in which the impurity diffusion component is well diffused.

In the diffusion step, the temperature increase rate when the substrate surface is heated to a desired diffusion temperature is preferably 25 ° C /sec or more, and is preferably as high as possible in the range in which the impurity diffusion component is well diffused.

Further, in the case of using the semiconductor element formed by the semiconductor substrate produced by the method of the present invention, it is necessary to diffuse the impurity diffusion component at a high concentration in a region where the surface of the semiconductor substrate is shallow.

In this case, in the above-described impurity diffusion method, it is preferable to rapidly cool the surface of the substrate to a predetermined diffusion temperature, and then rapidly cool the temperature distribution on the surface of the semiconductor substrate. The heat treatment by such a temperature distribution is called spike annealing.

In the peak annealing, the holding time at the predetermined diffusion temperature is preferably 1 second or shorter. Further, the diffusion temperature is preferably 950 to 1050 °C. By performing peak annealing by such a diffusion temperature and a holding time, it is easy to diffuse the impurity diffusion component at a high concentration in a region where the surface of the semiconductor substrate is shallow.

In the peak annealing, the holding time at the predetermined diffusion temperature is preferably 1 second or shorter. Further, the diffusion temperature is preferably 950 to 1050 °C. By performing peak annealing by such a diffusion temperature and a holding time, it is easy to diffuse the impurity diffusion component at a high concentration in a region where the surface of the semiconductor substrate is shallow.

As described above, when the diffusing agent composition of the present invention is used, even when the diffusing agent composition is coated on the semiconductor substrate with a film thickness of a nanometer order, the impurity diffusing component can be well diffused in the semiconductor substrate. .

Although the reason for obtaining the above effects is not clear, it is considered to be the following reasons.

When the diffusing agent composition of the present invention is applied to a semiconductor substrate, the hydrolyzable decane compound (B) is hydrolyzed and condensed on the surface of the substrate by moisture in the environment to form a film of the diffusing agent composition on the surface of the semiconductor substrate. The hydrolyzable decane compound (B) has a rapid reaction rate by hydrolysis and condensation, and reacts with some micro moisture in the coating environment, and can form an extremely thin film by performing a reaction at the time of coating the substrate, but on the other hand, In the composition The reaction is carried out with moisture, and it is partially hydrolyzed and polycondensed before coating. However, in the case where the water content of the diffusing agent composition of the present invention is less than or equal to the upper limit, the hydrolysis and polycondensation is suppressed to a minimum in the solution of the diffusing agent composition, and a uniform and extremely thin coating film can be formed. . As a result, it is considered that the impurity diffusion component (A) can be well diffused on the semiconductor substrate.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples.

[Examples 1 to 4, and Comparative Examples 1 and 2]

The following materials were used as components of the diffusing agent composition. As the impurity-diffusing component (A), tri-n-butoxyarsenic (a concentration of 4% by mass of an acetic acid-n-butyl ester solution) was used. As the hydrolyzable decane compound (B), tetraisocyanate decane is used. As the organic solvent (S), n-butyl acetate was used.

The impurity diffusion component (A), the hydrolyzable decane compound (B), and the organic solvent (S) are uniformly mixed so that the solid content concentration is 0.6% by mass and the element ratio of As/Si is 0.5, and the pore diameter is 0.2. The filter of μm was filtered to obtain a diffusing agent composition.

The water content of the diffusing agent composition was adjusted by dehydrating the organic solvent (S) before mixing using a molecular sieve, and the diffusing agent compositions of Examples 1 to 4 and Comparative Examples 1 and 2 were obtained.

The above-described diffusing agent composition was applied by a spin coater to form a film on the surface of a tantalum substrate (4 inches, P type) having a flat surface. A coating film having a thickness of 4.5 nm.

After the formation of the coating film, diffusion treatment of the impurity diffusion component is performed by the following method.

First, the coated film was baked on a hot plate. Next, using a rapid thermal annealing device (MILA-3000, lamp annealing device) manufactured by ULVAC, heating at a temperature increase rate of 10 ° C / sec under a nitrogen flow rate of 1 L / m, and maintaining at a diffusion temperature of 1000 ° C Diffusion was carried out under conditions of 1 minute. After the diffusion is completed, the semiconductor substrate is rapidly cooled to room temperature.

After the diffusion treatment, the sheet resistance value of the surface on which the diffusion treatment of the impurity diffusion component of the P-type tantalum substrate was carried out was determined by a four-probe method using a sheet resistance measuring device (Napson RG-200PV). The measured sheet resistance values are shown in Table 1. From the measured sheet resistance value, the diffusion state of the impurity diffusion component was determined based on the following criteria.

◎: The sheet resistance value was 500 ohm/sq. or less.

○: The sheet resistance value exceeded 500 ohm/sq., and was 1,000 ohm/sq. or less.

△: The sheet resistance value exceeded 1,000 ohm/sq., and was 1,300 ohm/sq. or less.

×: The sheet resistance value exceeded 1,300 ohm/sq.

As is apparent from Table 1, when the diffusing agent compositions of Comparative Examples 1 and 2 having a water content of more than 0.05% by mass were used, the sheet resistance of the semiconductor substrate after the diffusion treatment was high, and the impurity-diffusing component could not be well diffused.

In addition, it is understood from Examples 1 to 4 that when the water content of the diffusing agent composition is 0.05% by mass or less, and particularly, it is 0.015% by mass or less, the sheet resistance value of the semiconductor substrate is remarkably lowered, and the impurity diffusing component is well diffused.

[Examples 5 to 7]

The following materials were used as components of the diffusing agent composition. As the impurity-diffusing component (A), tri-n-butoxyarsenic (a concentration of 4% by mass of an acetic acid-n-butyl ester solution) was used. As the hydrolyzable decane compound (B), tetraisocyanate decane is used. As the organic solvent (S), n-butyl acetate was used.

The above impurity diffusion component (A), the hydrolyzable decane compound (B), and the organic solvent (S) have a solid concentration of 0.40 mass. After the element ratio of % and As/Si was 0.77, the mixture was uniformly mixed, and then filtered with a filter having a pore size of 0.2 μm to obtain a diffusing agent composition.

The water content of the diffusing agent composition was adjusted by dehydrating the organic solvent (S) before mixing using molecular sieves to obtain the diffusing agent compositions of Examples 5 to 7.

The above-described diffusing agent composition was applied by a spin coater to form a coating film of the film thickness shown in Table 2 on the surface of a tantalum substrate (4 inches, P type) having a flat surface.

After the formation of the coating film, diffusion treatment of the impurity diffusion component is performed by the following method.

First, the coated film was baked on a hot plate. Next, using a rapid thermal annealing device (MILA-3000, lamp annealing device) manufactured by ULVAC, heating at a temperature increase rate of 10 ° C / sec under a nitrogen flow rate of 1 L / m, and maintaining at a diffusion temperature of 1000 ° C The condition is spread under the condition of 7 seconds. After the diffusion is completed, the semiconductor substrate is rapidly cooled to room temperature.

After the diffusion treatment, the sheet resistance value of the surface on which the diffusion treatment of the impurity diffusion component of the P-type tantalum substrate was carried out was determined by a four-probe method using a sheet resistance measuring device (Napson RG-200PV). The measured sheet resistance values are shown in Table 2. From the measured sheet resistance value, the diffusion state of the impurity diffusion component was determined based on the following criteria.

◎: The sheet resistance value was 500 ohm/sq. or less.

○: The sheet resistance value exceeded 500 ohm/sq., and was 1,000 ohm/sq. or less.

△: The sheet resistance value exceeds 1,000 ohm/sq., and is 1,300 ohm/sq. the following.

×: The sheet resistance value exceeded 1,300 ohm/sq.

From the above results, when the moisture content of the diffusing agent composition containing tetraisocyanate decane is 0.05% by mass or less, the holding time at the diffusion treatment temperature is shortened from 60 seconds to 7 seconds in Examples 1 to 4 The impurity diffusion component can also diffuse well.

[Examples 8 and 9]

The following materials were used as components of the diffusing agent composition. As the impurity diffusion component (A), trimethyl borate is used. As the hydrolyzable decane compound (B), tetraisocyanate decane is used. As the organic solvent (S), n-butyl acetate was used.

The above-mentioned impurity-diffusing component (A), the hydrolyzable decane compound (B), and the organic solvent (S) were uniformly mixed so that the solid content concentration was 1.42% by mass and the element ratio of B/Si was 1.95, and the pore diameter was 0.2. The filter of μm was filtered to obtain a diffusing agent composition.

The moisture content of the diffusing agent composition was adjusted by dehydrating the organic solvent (S) before mixing using a molecular sieve to obtain Examples 8 and 9. A diffuser composition.

The above-mentioned diffusing agent composition was applied by a spin coater to the same dehydrated n-butanol as that used in the diffusing agent composition after the surface of the tantalum substrate (4 inches, N type) having a flat surface. Cleaning was carried out to form a coating film having a film thickness of 10.8 nm.

After the formation of the coating film, diffusion treatment of the impurity diffusion component is performed by the following method.

First, the coated film was baked on a hot plate. Next, using a rapid thermal annealing device (MILA-3000, lamp annealing device) manufactured by ULVAC, heating at a temperature rise rate of 25 ° C / sec under a nitrogen flow rate of 1 L / m, and then at a diffusion temperature of 1100 ° C or 1200 °C, and the diffusion time as shown in Table 3 was carried out. After the diffusion is completed, the semiconductor substrate is rapidly cooled to room temperature.

After the diffusion treatment, the sheet resistance value of the surface on which the diffusion treatment of the impurity diffusion component was carried out on the tantalum substrate was obtained by a four-probe method using a sheet resistance measuring device (Napson RG-200PV), and it was confirmed whether or not an inverse from the N type to the P type was generated. turn.

As a result, the diffusion treatment at 1100 ° C and the diffusion treatment at 1200 ° C all produced an inversion from N type to P type. The sheet resistance values after the diffusion treatment are shown in Table 3.

From the above results, even when the impurity-diffusing component is a boron compound, when the water content of the diffusing agent composition containing tetraisocyanate decane is 0.05% by mass or less, the impurity-diffusing component can be favorably diffused.

[Examples 10 to 12]

The following materials were used as components of the diffusing agent composition. As the impurity-diffusing component (A), a phosphite (trimethylsulfanyl group) is used. As the hydrolyzable decane compound (B), methyl triisocyanate decane is used. As the organic solvent (S), n-butyl acetate was used.

The impurity diffusion component (A), the hydrolyzable decane compound (B), and the organic solvent (S) are uniformly mixed so that the solid content concentration is 0.43 mass% and the element ratio of P/Si is 0.45, and the pore diameter is 0.2. The filter of μm was filtered to obtain a diffusing agent composition.

The water content of the diffusing agent composition was adjusted by dehydrating the organic solvent (S) before mixing using molecular sieves to obtain the diffusing agent compositions of Examples 10 to 12.

The above-mentioned diffusing agent composition was applied using a spin coater on a surface of a tantalum substrate (4 inches, P type) having a flat surface, The coating film having the film thickness described in Table 4 was formed by washing with dehydrated n-butanol which was the same as that of the diffusing agent composition.

After the formation of the coating film, diffusion treatment of the impurity diffusion component is performed by the following method.

First, the coated film was baked on a hot plate. Next, using a rapid thermal annealing device (MILA-3000, lamp annealing device) manufactured by ULVAC, heating at a temperature rise rate of 25 ° C / sec under a nitrogen flow rate of 1 L / m, and then at a diffusion temperature of 1000 ° C or 1100 °C, and the diffusion was carried out in the retention time described in Table 4. After the diffusion is completed, the semiconductor substrate is rapidly cooled to room temperature.

After the diffusion treatment, the sheet resistance value of the surface on which the diffusion treatment of the impurity diffusion component was carried out on the tantalum substrate was obtained by a four-probe method using a sheet resistance measuring device (Napson RG-200PV), and it was confirmed whether or not a cross from the P type to the N type was generated. turn.

As a result, the diffusion treatment at 1000 ° C and the diffusion treatment at 1100 ° C all produced an inversion from P type to N type. The sheet resistance values after the diffusion treatment are shown in Table 4.

From the above results, even when the impurity-diffusing component is a phosphorus compound, when the water content of the diffusing agent composition containing tetraisocyanate decane is 0.05% by mass or less, the impurity-diffusing component can be favorably diffused.

Claims (1)

A diffusing agent composition which is a diffusing agent composition for diffusing impurities of a semiconductor substrate, characterized by comprising an impurity diffusing component (A) and a Si compound (B) represented by the following formula (1), the Si compound (B) can be hydrolyzed to form a sterol group, R _4-n Si(NCO) _n . . . (1) (In the formula (1), R is a hydrocarbon group, and n is an integer of 3 or 4) The water content in the diffusing agent composition is 0.05% by mass or less.