TW201439312A - Semiconductor substrate cleaning method and semiconductor substrate manufacturing method - Google Patents

Abstract

The method for cleaning a semiconductor substrate according to the present invention includes: a first cleaning operation for cleaning a semiconductor substrate on which a polishing process has been performed using the following cleaning agent (A) or a cleaning agent (B); and a second a cleaning operation, after the first cleaning operation, the semiconductor substrate is washed using the following cleaning agent (C); the cleaning agent (A): containing a hydrocarbon, a glycol ether, and a surfactant Liquid detergent; detergent (B): an alkali metal hydroxide, one or more selected from the group consisting of hydroxycarboxylic acids and salts thereof, and selected from 1-hydroxyethane-1,1-diphosphine One or more liquid detergents of an acid and a salt thereof; a detergent (C): a liquid detergent containing sulfuric acid and hydrogen peroxide and having a sulfuric acid concentration of 50% by mass or more.

Description

Semiconductor substrate cleaning method and semiconductor substrate manufacturing method Technical field

The present invention relates to a method of cleaning a semiconductor substrate and a method of manufacturing a semiconductor substrate.

The present invention claims priority from Japanese Patent Application No. 2012-251819, filed on Jan.

Background technique

A thin film is formed on the semiconductor substrate. The semiconductor substrate on which the thin film has been formed is supplied to the fabrication of the semiconductor device. In order to achieve an improvement in the performance of the semiconductor device or an increase in yield, it is necessary to form a film uniformly. Therefore, the semiconductor substrate requires a flat surface and is clean.

For example, a single crystal sapphire substrate (hereinafter sometimes referred to simply as a sapphire substrate) belonging to a semiconductor substrate for a light-emitting diode (LED) is manufactured as follows.

First, a sapphire substrate is produced by slicing a sapphire block called an ingot. The sapphire substrate is subjected to a polishing treatment (grinding step) by a polishing material such as citric acid. The sapphire substrate that has been subjected to grinding treatment will be attached The particles such as abrasive or polishing slag are dirty. Therefore, the surface of the sapphire substrate is cleaned (cleaning step).

A film of GaN, GaAs or the like is formed on the surface of the sapphire substrate thus obtained. A sapphire substrate on which a film has been formed is used in an LED or the like.

In the polishing step, the sapphire substrate is fixed to the polishing jig, and the sapphire substrate is subjected to a rubbing treatment. A method of fixing a sapphire substrate to a polishing jig includes: a method of adhering and fixing a sapphire substrate to a base of a polishing jig using a wax (wax fixing method); and a method of embedding and fixing a sapphire substrate in a concave portion which has been formed in a polishing jig (Fixed fixation method).

The sapphire substrate which has been subjected to the grinding treatment by the wax fixing method adheres to the wax. Therefore, it is necessary to remove particulate dirt and wax by a washing step.

Microparticles are adhered to both sides of the sapphire substrate which has been subjected to the grinding treatment by the fitting and fixing method. That is, the amount of adhesion of fine particles is large. Therefore, it is necessary to remove a large amount of fine particles by the washing step.

In the washing step, a suitable washing method is selected in accordance with the method of fixing the sapphire substrate in the polishing step or the like.

In general, in the washing step, for example, the sapphire substrate (solvent washing) is washed by an organic solvent such as acetone or isopropyl alcohol. Next, ammonia, hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, hydrogen peroxide, or the like is appropriately combined, and the sapphire substrate (RCA cleaning) is washed in multiple stages.

However, in the combination of solvent washing and RCA washing, there is a problem in that the fine particles which are detached from the sapphire substrate during washing are adhered to the sapphire substrate again, and it is difficult to improve the cleanness of the sapphire substrate.

In addition, since the RCA washing is complicatedly combined with the washing treatment of washing components such as ammonia, hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, and hydrogen peroxide, the washing step is troublesome.

Further, the RCA washing has a problem that the handling of the above-mentioned washing component is troublesome.

With respect to such a problem, for example, there is disclosed a method of cleaning a semiconductor substrate, comprising: a first cleaning step of washing by containing a hydrocarbon, a glycol ether, an anionic surfactant, and water. The semiconductor composition is washed by the agent composition; the second cleaning step is performed by washing the semiconductor substrate with water; and the third cleaning step comprises quaternary ammonium hydroxide, a chelating agent containing nitrogen and a carboxyl group, and water; The semiconductor substrate is washed in the order of the first cleaning step, the second cleaning step, and the third cleaning step (for example, Patent Document 1).

Advanced technical literature Patent literature

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2012-104671 Bulletin

Summary of invention

However, the method of cleaning a semiconductor substrate requires a further improvement in the cleanliness of the semiconductor substrate.

Therefore, an object of the present invention is to provide a method for cleaning a semiconductor substrate which can further improve the cleanliness of a semiconductor substrate more easily.

The method for cleaning a semiconductor substrate of the present invention comprises: first cleaning The operation uses the following detergent (A) or the following detergent (B) to wash the semiconductor substrate which has been subjected to the polishing treatment; and a second cleaning operation, which is used after the first cleaning operation The semiconductor substrate is washed by the following cleaning agent (C).

Detergent (A): A liquid detergent containing a hydrocarbon, a glycol ether, and a surfactant.

Detergent (B): an alkali metal hydroxide, one or more selected from the group consisting of hydroxycarboxylic acids and salts thereof, and one selected from 1-hydroxyethane-1,1-diphosphonic acid and salts thereof One or more liquid detergents.

Detergent (C): A liquid detergent containing sulfuric acid and hydrogen peroxide and having a sulfuric acid concentration of 50% by mass or more.

The method for cleaning a semiconductor substrate of the present invention preferably further includes: a third cleaning operation of reusing the detergent (A) or the detergent (B) after the second cleaning operation, and washing the a semiconductor substrate; and a fourth cleaning operation, after the third cleaning operation, reusing the cleaning agent (C) to wash the semiconductor substrate.

In the method for cleaning a semiconductor substrate of the present invention, it is more preferred to use the detergent (A) in the first cleaning operation and to use the detergent (B) in the third cleaning operation. ).

Further, in the method for cleaning a semiconductor substrate of the present invention, it is preferable that the detergent (B) is used in the first cleaning operation, and the detergent is used in the third cleaning operation. (B).

Further, in the method of cleaning a semiconductor substrate of the present invention, the semiconductor substrate may be a single crystal sapphire substrate.

A method of manufacturing a semiconductor substrate of the present invention has a The cleaning method of the semiconductor substrate of the present invention is a step of cleaning the semiconductor substrate.

In other words, the method for manufacturing a semiconductor substrate of the present invention includes a substrate manufacturing step of slicing an ingot to form a substrate, a polishing step of performing a polishing treatment on the substrate using the polishing material, and a cleaning step of using the semiconductor substrate of the present invention The cleaning method is to clean the semiconductor substrate on which the polishing process has been performed.

According to the method for cleaning a semiconductor substrate of the present invention, it is possible to more easily produce a semiconductor substrate having improved cleaning power.

Form for implementing the invention (Method of Manufacturing Semiconductor Substrate)

The method for producing a semiconductor substrate of the present invention includes a step of cleaning a semiconductor substrate which has been subjected to a polishing process by a method for cleaning a semiconductor substrate of the present invention (hereinafter, simply referred to as a cleaning method).

<washing step>

The washing step is a step of washing the semiconductor substrate on which the polishing treatment has been performed, and includes a first cleaning operation and a second cleaning operation which will be described later.

"First Washing Operation"

In the first cleaning operation, the semiconductor substrate on which the polishing treatment has been performed is cleaned using the following cleaning agent (A) or the following cleaning agent (B).

Detergent (A): A liquid detergent containing a hydrocarbon, a glycol ether, and a surfactant.

Detergent (B): a hydroxide containing an alkali metal, one or more selected from the group consisting of a hydroxycarboxylic acid and a salt thereof (hydroxycarboxylic acid (salt)), and selected from 1-hydroxyethane-1,1- A liquid detergent of one or more kinds of bisphosphonic acids and salts thereof (1-hydroxyethane-1,1-diphosphonic acid (salt)).

[Detergent (A)]

The detergent (A) is a liquid detergent containing a hydrocarbon, a glycol ether, and a surfactant. The detergent (A) has a high detergency against fine particles and has a particularly high detergency against grease stains such as wax.

The detergent (A) contains a hydrocarbon, whereby the stain of the wax or the like which has adhered to the semiconductor substrate can be favorably removed.

Therefore, when cleaning a semiconductor substrate which has been subjected to a polishing treatment by a wax fixing method, it is preferable to use a detergent (A).

The hydrocarbon may be a saturated hydrocarbon or an unsaturated hydrocarbon. For example, a paraffin-based hydrocarbon, an olefin-based hydrocarbon, an aromatic hydrocarbon, an alkylbenzene-based hydrocarbon, an alkylnaphthalene-based hydrocarbon, or the like can be given. These hydrocarbons may be used alone or in combination of two or more.

For example, the hydrocarbon is preferably one or more selected from the group consisting of a saturated hydrocarbon represented by the following general formula (a1) and an unsaturated hydrocarbon represented by the following general formula (a2). Compound.

C _m H _2m+2 (a1)

In the formula (a1), m is preferably 8 to 20, and more preferably 10 to 18, and further preferably It is 10~14. If m is less than the aforementioned lower limit, the ignitability is improved. When m is more than the above upper limit, the blending stability of the detergent (A) is lowered, and the detergent (A) is easily clouded.

C _n H _2n (a2)

In the formula (a2), n is preferably from 8 to 20, and more preferably from 10 to 18. If n is less than the aforementioned lower limit, the ignitability is improved. When n is more than the above upper limit, the blending stability of the detergent (A) is lowered, and the detergent (A) is easily clouded.

For example, commercially available hydrocarbons include, for example, Cactus Normal Paraffin N12D (trade name, m in the formula (a1) is 12-dodecane, manufactured by JX Nippon Mining Co., Ltd.), and liquid. Paraffin No. 30 (trade name, compound of formula (a1) is a compound of 12-14, manufactured by Central Chemicals Co., Ltd.), and Linealene 14 (trade name, compound of formula (a2) where n is 14 Production Co., Ltd.) and so on.

The content of the hydrocarbon in the detergent (A) can be determined in consideration of the type of the hydrocarbon or the like. For example, it is preferably 1 to 20% by mass, and more preferably 3 to 10% by mass.

The detergent (A) contains a glycol ether, whereby the hydrocarbon and the surfactant can be solubilized in the dispersion medium to improve liquid stability.

For example, the glycol ether may, for example, be a compound represented by the following general formula (a10).

R ¹ -O-(R ³ O) _p -R ² (a10)

In the formula (a10), R ¹ is a linear or branched alkyl group having 4 to 8 carbon atoms, a linear or branched alkenyl group having 4 to 8 carbon atoms, a phenyl group or a benzyl group, and preferably A chain or a branched alkyl group.

R ³ O is an oxyalkylene group having 2 to 4 carbon atoms and contains at least 1 unit of an oxyethylene group in the structure.

p is the number of 1 to 4 showing the average number of repetitions of R ³ O.

R ² is a hydroxyl group, a linear or branched alkyl group having 1 to 4 carbon atoms or a linear or branched alkenyl group having 1 to 4 carbon atoms.

The glycol ether may, for example, be diethylene glycol monohexyl ether (C ₆ H ₁₃ O(CH ₂ CH ₂ O) ₂ H, for example, Hexyl Di Glycol manufactured by Nippon Emulsifier Co., Ltd. ( Trade name)), dipropylene glycol monobutoxyethyl ether (C ₄ H ₉ OC ₂ H ₄ O(C ₃ H ₆ O) ₂ H, for example, Leosolb 703B (trade name) manufactured by Lion Co., Ltd.), Diethylene glycol dibutyl ether (C ₄ H ₉ O(C ₂ H ₄ O) ₂ C ₄ H ₉ , such as Di Butyl Di Glycol manufactured by Nippon Emulsifier Co., Ltd. (Commodity Name)), triethylene glycol monobutyl ether (C ₄ H ₉ O(CH ₂ CH ₂ O) ₃ H, such as Butysenol (made by KH Neochem Co., Ltd.) 30 (trade name)), ethylene glycol mono(2-ethylhexyl)ether (C ₈ H ₁₇ O(CH ₂ CH ₂ O) ₂ H, for example, diethylene glycol 2-produced by Nippon Emulsifier Co., Ltd. Ethylhexyl ether (2-Ethyl Hexyl Di Glycol) (trade name) and diethylene glycol monobutyl ether (C ₄ H ₉ O(C ₂ H ₄ O) ₂ H, for example, manufactured by Japan Emulsifier Co., Ltd. Butyl Di Glycol (trade name) and the like. Among them, diethylene glycol butyl ether, diethylene glycol dibutyl ether and diethylene glycol 2-ethylhexyl ether are preferred. These glycol ethers may be used alone or in combination of two or more.

The content of the glycol ether in the detergent (A) can be determined in consideration of the type of the glycol ether, etc., and is, for example, preferably 5 to 50% by mass, and more preferably 15 to 40% by mass.

The detergent (A) contains a surfactant, whereby fine particles, wax, and the like which have adhered to the semiconductor substrate to be cleaned can be removed more satisfactorily.

The surfactant may, for example, be an anionic surfactant or a nonionic surfactant, and among them, an anionic surfactant is preferred.

The anionic surfactant is not particularly limited, and is exemplified by a dialkyl sulfosuccinate. The type of the alkyl group in the dialkyl sulfosuccinate and the kind of the salt are not particularly limited. For example, the dialkyl sulfosuccinate may, for example, be a sodium dialkyl sulfosuccinate or an ammonium salt of a dialkyl sulfosuccinate. Among them, dialkylsulfosuccinate sodium salt is preferred, and is preferably dioctylsulfosuccinate sodium salt from the viewpoint of being inexpensive and easy to obtain. These anionic surfactants may be used alone or in combination of two or more.

Commercial products of sodium dioctylsulfosuccinate are exemplified by Lipal 870P (trade name, manufactured by Lion King Co., Ltd.).

The nonionic surfactant may, for example, be a compound represented by the following general formula (a20).

R ¹¹ -O-(R ¹² O) _r -H. . . (a20)

In the formula (a20), R ¹¹ is a linear or branched alkyl group having 8 to 20 carbon atoms, or a linear or branched alkenyl group having 8 to 20 carbon atoms, a phenyl group or a benzyl group.

R ^{11 is} preferably an alkyl group or an alkenyl group.

The carbon number of R ¹¹ is preferably from 8 to 14, and more preferably from 8 to 10.

R ¹² O is an oxyalkylene group having 2 to 4 carbon atoms and contains at least 1 unit of oxyethylene group in the structure. R ¹² O is preferably an oxyalkylene group having 2 to 3 carbon atoms.

r is the number of 8 to 20 showing the average number of repetitions of R ¹² O, and is preferably 12 to 20, more preferably 14 to 20.

The compound represented by the formula (a20) may, for example, be a polyoxyalkylene alkyl ether, a polyoxyalkylene alkylphenyl ether or a polyoxyalkylene propylene phenyl ether.

The commercial product of the compound represented by the formula (a20) can be, for example, a Dobanox series (trade name, manufactured by Lion King Co., Ltd.), a Leocol series (trade name, manufactured by Lion King Co., Ltd.), and a Leox series (product). Name, lion king Co., Ltd.), Newcol series (trade name, manufactured by Japan Emulsifier Co., Ltd.), Softanol series (trade name, manufactured by Nippon Shokubai Co., Ltd.), Noigen series (trade name, first industrial pharmaceutical) Co., Ltd.) and so on. Among them, a compound represented by C ₁₀ H ₂₁ O(CH ₂ CH ₂ O) ₁₄ H (for example, Noigen XL-140 (trade name) manufactured by Dai-ichi Kogyo Co., Ltd.), and by C ₈ A compound represented by H ₁₇ O(CH ₂ CH ₂ O) ₂₀ H (for example, Newcol 1020 (trade name) manufactured by Nippon Emulsifier Co., Ltd.). These nonionic surfactants may be used alone or in combination of two or more.

In the detergent (A), the surfactant may be used singly or in combination of two or more.

The content of the surfactant in the detergent (A) can be determined in consideration of the type of the surfactant, etc., and is preferably 1 to 20% by mass, and more preferably 3 to 15% by mass.

The detergent (A) may contain any components such as water, a chelating agent, an antioxidant, a rust preventive, an antifoaming agent, and a pH adjuster which are dispersion media.

For example, the water content in the detergent (A) is preferably from 30 to 80% by mass.

Examples of the chelating agent include: citric acid, tartaric acid, malic acid, and B. Diaminetetraacetic acid (EDTA), triethylenetetraacetic acid (TTHA), glycine diacetic acid (MGDA), 1,3-propane-2-diaminetetraacetic acid (PDTA), hydroxyethyl ethylenediamine triacetic acid (HEDTA), hydroxyethyliminodiacetic acid (HIDA), nitrotriacetic acid (NTA), diethylenetriamine pentaacetic acid (DTPA), propylenediaminetetraacetic acid, ethylenediaminetetrapropionic acid, cyclohexyl Alkyl-1,2-diaminetetraacetic acid, iminodisuccinic acid, aspartic acid diacetic acid, beta-alanine diacetic acid, hydroxyiminodisuccinic acid, and salts of such acids. Examples of the base for forming a salt include sodium, potassium, calcium, magnesium, and the like.

For example, the antioxidant may, for example, be a phenol system such as 2,6-di-tertiary butanol, 2-tris-butyl-4-methoxyphenol or 2,4-dimethyl-6-tertiary butylphenol. Antioxidant; monoalkyldiphenylamine such as monooctyldiphenylamine or monodecyldiphenylamine, dialkyldiphenylamine such as 4,4'-dibutyldiphenylamine or 4,4'-dipentyldiphenylamine An amine-based antioxidant such as polyalkyldiphenylamine such as tetrabutyldiphenylamine or tetrahexyldiphenylamine, or naphthylamine such as α-naphthylamine or benzene-α-naphthylamine; phenothiazine or pentaerythritol- a sulfur-based compound such as cerium-(3-laurylthiopropionate) or bis(3,5-tris-butyl-4-hydroxybenzyl) sulfide; and bis(2,4-di-tridecyl) Phosphorus-based antioxidants such as benzene) pentaerythritol diphosphate, phenyl diisononyl phosphite, diphenyl diisooctyl phosphate, and triphenyl phosphate.

For example, examples of the rust inhibitor include benzotriazole, tolyltriazole, benzotriazole having a hydrocarbon group having 2 to 10 carbon atoms, benzimidazole, and imidazole having a hydrocarbon group having 2 to 20 carbon atoms. a nitrogen-containing organic rust inhibitor having a hydrocarbyl group having 2 to 20 carbon atoms or a 2-indole benzothiazole; a dodecene succinic acid half ester, an octadecene succinic anhydride or a dodecene succinic acid decylamine Alkyl succinic acid and alkenyl succinic acid; and polyhydric alcohol partial esters such as sorbitan monooleate, glycerol monooleate or pentaerythritol monooleate.

For example, examples of the antifoaming agent include a decane defoaming agent containing dimethyloxane, fluorononane or polyether siloxane.

Examples of the acidic pH adjuster include phosphoric acid and carboxylic acid other than those disclosed in the above chelating agent.

For example, the carboxylic acid is preferably an aliphatic carboxylic acid such as butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, capric acid, capric acid or dodecanoic acid; and benzoic acid, p-tert-butylbenzoic acid, An aromatic carboxylic acid such as capric acid, isophthalic acid or p-citric acid.

Examples of the alkaline pH adjuster include an alkanolamine, a quaternary ammonium hydroxide, and an inorganic salt.

For example, the alkanolamine may, for example, be monoethanolamine, diethanolamine or triethanolamine.

For example, the quaternary ammonium hydroxide may, for example, be tetramethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, methyltrihydroxyethylammonium hydroxide or dimethyldihydroxyethylammonium hydroxide. , tetraethylammonium hydroxide and trimethylethylammonium hydroxide.

For example, examples of the inorganic salt include sodium hydroxide and potassium hydroxide.

The content of the pH adjuster in the detergent (A) can be determined depending on the type of the pH adjuster or the like.

The pH of the detergent (A) can be appropriately determined in consideration of the composition of the detergent (A), the material of the semiconductor substrate, and the like.

The detergent (A) can be prepared in accordance with a conventionally known method of preparing a liquid detergent.

For example, it can be prepared by dispersing a hydrocarbon, a glycol ether, a surfactant, and optionally any component in water belonging to a dispersion medium. Detergent (A).

[detergent (B)]

The detergent (B) is a liquid detergent containing an alkali metal hydroxide, a hydroxycarboxylic acid (salt), and 1-hydroxyethane-1,1-diphosphonic acid (salt). Since the detergent (B) can be finely peeled off from the semiconductor substrate, and the fine particles can be more reliably prevented from re-adhesive, the cleaning power against the fine particles is particularly high. That is, the detergent (B) is suitable for cleaning a semiconductor substrate having a large amount of adhesion of fine particles.

Therefore, when cleaning a semiconductor substrate which has been subjected to a polishing treatment by a fitting fixing method, it is preferable to use a detergent (B).

For example, the alkali metal hydroxide may, for example, be sodium hydroxide or potassium hydroxide. The alkali metal hydroxide can improve the detergency by the addition effect with a hydroxycarboxylic acid (salt) or 1-hydroxyethane-1,1-diphosphonic acid (salt) described later.

The content of the hydroxide of the alkali metal in the detergent (B) is preferably from 0.1 to 15% by mass, and more preferably from 1 to 10% by mass.

The hydroxycarboxylic acid (salt) can be improved in detergency by an addition effect with a hydroxide of an alkali metal or a 1-hydroxyethane-1,1-diphosphonic acid (salt) described later.

Examples of the hydroxycarboxylic acid (salt) include citric acid, salicylic acid, gluconic acid, glycolic acid, lactic acid, hydroxybutyric acid, malic acid, tartaric acid, gallic acid, hydroxyiminodiacetic acid (HIDA), and hydroxyla. Aminodisuccinic acid (HIDS), hydroxyethylethylenediaminetriacetic acid (HEDTA), dihydroxyethylglycine (DHEG), 1,3-diamino-2-hydroxypropanetetraacetic acid (DTPA-OH) ), heptanogluconic acid, and the like. The salt constituting the hydroxycarboxylic acid salt may, for example, be sodium or potassium. Among them, citric acid or a salt thereof is preferred, and sodium citrate is more preferred. Hydroxycarboxylic acid (salt) These may be used alone or in combination of two or more.

The content of the hydroxycarboxylic acid (salt) in the detergent (B) is preferably from 0.1 to 15% by mass, and more preferably from 1 to 10% by mass.

1-Hydroxyethane-1,1-diphosphonic acid (salt) can improve the detergency by the addition effect with an alkali metal hydroxide or a hydroxycarboxylic acid (salt).

For example, 1-hydroxyethane-1,1-diphosphonic acid (salt) can be exemplified by 1-hydroxyethane-1,1-diphosphonic acid and 1-hydroxyethane-1,1-diphosphine. The sodium salt, potassium salt, ammonium salt, monoethanolamine salt, diethanolamine salt or triethanolamine salt of the acid, wherein sodium salt of 1-hydroxyethane-1,1-diphosphonic acid is preferred.

The content of 1-hydroxyethane-1,1-diphosphonic acid (salt) in the detergent (B) is preferably from 0.1 to 20% by mass, and more preferably from 1 to 15% by mass.

Like the detergent (A), the detergent (B) may contain water or a pH adjuster (but in addition to the alkali metal hydroxide) and a chelating agent (except for the hydroxycarboxylic acid (salt) and Any component such as 1-hydroxy-1,1-diphosphonic acid (salt), a surfactant, an antioxidant, a rust preventive or an antifoaming agent.

For example, the water content in the detergent (B) is preferably from 30 to 80% by mass.

The pH of the detergent (B) can be appropriately determined in consideration of the composition of the detergent (B), the material of the semiconductor substrate, and the like.

The detergent (B) can be prepared in accordance with a conventionally known method of preparing a liquid detergent.

For example, by dissolving an alkali metal hydroxide, a hydroxycarboxylic acid (salt), 1-hydroxyethane-1,1-diphosphonic acid (salt), and optionally, any component in water belonging to a dispersion medium The detergent (B) can be prepared.

For example, the first washing operation can be enumerated, for example, a method of immersing a polished semiconductor substrate (hereinafter sometimes referred to as a polished substrate) in a cleaning liquid (first cleaning liquid) containing a cleaning agent (A) or a cleaning agent (B); a method in which a substrate is immersed in a first cleaning liquid and ultrasonic waves are applied (ultrasonic wave application method); and a method in which the first cleaning liquid is sprayed on the substrate after polishing and then wiped off.

The first cleaning operation is preferably a method of immersing the polished substrate in the first cleaning liquid and applying ultrasonic waves.

For example, the polishing substrate may be subjected to a polishing treatment (polishing step) on an unpolished semiconductor substrate (hereinafter sometimes referred to as an original plate) by a polishing material such as phthalic acid glue. Examples of the substrate to be polished include a single crystal sapphire substrate, a tantalum substrate, and a SiC substrate. Among them, a single crystal sapphire substrate is preferable.

The polishing method of the original plate in the polishing step may be, for example, a method in which the original plate is fixed by a wax fixing method or a fitting fixing method, and a slurry containing the polishing material is supplied to the original plate, and the original plate is ground by a grinder.

The content of the detergent in the first cleaning liquid can be appropriately determined in consideration of the type of the detergent or the like. When the detergent (A) is used, it is preferred to use the detergent (A) as the first cleaning liquid. When the detergent (B) is used, it is preferred to form the first cleaning liquid by diluting the amount of the detergent (B) to 1 to 20% by mass.

The device to be used in the ultrasonic wave application method is not particularly limited, and examples thereof include UO300FB-PY (manufactured by Hitachi International Electric Co., Ltd.).

The temperature condition in the first washing operation can be determined according to the type of the detergent or the like. The temperature condition when the detergent (A) is used is, for example, preferably 40 to 60 °C. The temperature condition when the detergent (B) is used is, for example, preferably 25 to 60 °C.

The time in the first washing operation can be appropriately determined according to the washing method or the like. For example, in the ultrasonic wave applying method, it is preferably 5 to 20 minutes.

The first cleaning operation may also include a first washing process, and the first washing process is to wash the polished substrate by water after the substrate is washed and polished by the first cleaning liquid.

"Second Washing Operation"

In the second cleaning operation, the semiconductor substrate which has been washed by the first cleaning operation is cleaned using the following cleaning agent (C).

Detergent (C): A liquid detergent containing sulfuric acid and hydrogen peroxide and having a sulfuric acid concentration of 50% by mass or more.

By providing the second cleaning operation after the first cleaning operation, it is possible to more effectively remove the dirt or the like of the fine particles that have adhered to the semiconductor substrate.

[detergent (C)]

The detergent (C) contains sulfuric acid and hydrogen peroxide.

The content of sulfuric acid in the detergent (C) is 50% by mass or more, and preferably 75% by mass or more, and more preferably 80% by mass or more. If it is less than the said lower limit, the improvement of the washing|cleaning of the microparticles dirty cannot be acquired.

The content of hydrogen peroxide in the detergent (C) is preferably from 1 to 30% by mass, and more preferably from 1 to 20% by mass, particularly preferably from 1 to 10% by mass, and more preferably from 5 to 20% by mass. %. If it is less than the above lower limit value, the hydrogen peroxide is too small and the detergency of the microparticles is reduced. If it is larger than the above upper limit, there is a violent reaction between sulfuric acid and hydrogen peroxide.

The detergent (C) may also contain water as an optional component.

The cleaning method in the second cleaning operation may be, for example, immersing the polished substrate (the one-time washed substrate) which has been washed by the first cleaning operation in the second cleaning containing the cleaning agent (C). The method in the liquid. The detergent (C) was used as the second cleaning liquid without being diluted. For example, the second cleaning operation may be, for example, a method of pre-mixing sulfuric acid and hydrogen peroxide to form a second cleaning liquid, and immersing the washed substrate in the second cleaning liquid; and sulphuric acid; It is placed in a container, and the substrate which has been washed once is immersed in sulfuric acid in the container, followed by a method of adding hydrogen peroxide to sulfuric acid or the like. If hydrogen peroxide is added to the sulfuric acid, caloric acid (peroxysulfate) is formed. Since the rosin acid has a strong oxidizing power, it is easy to be oxidatively decomposed and adhered to the organic substance washed once at a time to form CO ₂ removal. In the second washing operation, when the formation of caroic acid is reduced, it is preferred to add hydrogen peroxide to the sulfuric acid as appropriate.

Further, in this step, it is not preferable to dry the washed substrate once and supply it to the second cleaning operation. When the washed substrate is dried once, the dirt remaining on the primary cleaning substrate is fixed to the substrate, and it is difficult to remove the dirt that has been fixed.

The temperature condition in the second washing operation is preferably from 90 to 130 ° C, and more preferably from 110 to 130 ° C. When the amount is less than the lower limit, the cleaning power is lowered, and if it is larger than the above upper limit, the container used in the second cleaning operation is likely to be deteriorated.

The washing time in the second washing operation is preferably 5 to 10 minutes, and more preferably 7 to 10 minutes. When the amount is less than the lower limit, the cleaning power is lowered. When the amount is larger than the upper limit, the time required for the second cleaning operation is too long, and the productivity of the semiconductor substrate is lowered.

The second washing operation may also have a washing process, and the aforementioned washing place After cleaning the substrate by washing with the second cleaning solution once, the substrate is washed once by water.

The semiconductor substrate which has been cleaned by the first cleaning operation and the second cleaning operation is dried, and a thin film is formed on the surface of the semiconductor substrate by GaN, GaAs or the like. The semiconductor substrate on which the thin film has been formed is supplied to the fabrication of the semiconductor device.

According to the method for cleaning a semiconductor substrate of the present embodiment, it is possible to remove the fine particles which have adhered to the semiconductor substrate, and the like, by the simple method of performing the second cleaning operation after the first cleaning operation, and further Improve the cleanliness of the semiconductor substrate.

According to the method for producing a semiconductor substrate of the present embodiment, it is possible to obtain a fine method of performing the second cleaning operation after the first cleaning operation, thereby removing the fine particles which have adhered to the semiconductor substrate, and the like. A semiconductor substrate with improved cleaning power.

Further, in the semiconductor substrate produced by the present invention, the number of residual particles is preferably 1000/sheet or less, and more preferably 500/sheet or less, further preferably 200/sheet or less, and particularly preferably 100/ Below the film.

It is preferable that the lower limit of the number of residual particles is 0, however, it is also possible to constitute 10 or more.

(Other embodiments)

The present invention is not limited to the foregoing embodiment.

In the above embodiment, the washing step is constituted by the first washing operation and the second washing operation. However, the present invention is not limited thereto, and the detergent (A) or the detergent may be sequentially used ( B) Washing operation and using detergent (C) The operation to wash.

For example, the first washing operation and the second washing operation may be continued, and the third washing operation is the same as the first washing operation; and the fourth washing operation is the same as the second washing operation. That is, the semiconductor substrate can be cleaned by repeating the cleaning step in the above embodiment. There are no special restrictions on the number of repetitions of the washing step.

The third cleaning operation may use the same detergent as the first cleaning operation, or a different detergent may be used.

For example, when cleaning a semiconductor substrate which has been subjected to a rubbing treatment by a wax fixing method, it is preferable to use a detergent (A) in the first cleaning operation and a detergent in the third cleaning operation ( B).

By the above configuration, the wax which has adhered to the semiconductor substrate can be removed by the first cleaning operation, and the fine particles can be removed by the third cleaning operation.

Further, for example, when the semiconductor substrate which has been subjected to the polishing treatment by the fitting and fixing method is washed, it is preferable to use the detergent (B) in the first cleaning operation and the third cleaning operation. By forming the above structure, it is possible to more effectively remove a large amount of fine particles which have adhered to the semiconductor substrate.

Or, for example, the same washing operation as the first washing operation may be provided before the first washing operation.

[Examples]

Hereinafter, the present invention will be described in detail by showing examples, however, the present invention is not limited by the following description.

(using raw materials) <Cleanse (A)> Hydrocarbons

‧ Dodecane (C ₁₂ H ₂₆ ): Cactus Normal Paraffin N12D (trade name), manufactured by JX Nippon Mining & Energy Co., Ltd.

Glycol ether

‧ Diethylene glycol butyl ether (C ₄ H ₉ O(C ₂ H ₄ O) ₂ H): manufactured by Nippon Emulsifier Co., Ltd.

‧ Diethylene glycol dibutyl ether (C ₄ H ₉ O(C ₂ H ₄ O) ₂ C ₄ H ₉ ): manufactured by Nippon Emulsifier Co., Ltd.

‧ Diethylene glycol 2-ethylhexyl ether (C ₈ H ₁₇ (OCH ₂ CH ₂ ) ₂ OH): manufactured by Nippon Emulsifier Co., Ltd.

Surfactant

‧ Dioctylsulfosuccinate (C ₂₀ H ₃₈ O ₇ SNa): Lipal 870P (trade name), manufactured by Lion King Co., Ltd.

<Cleanse (B)> Alkali Metal Hydroxide

‧ Sodium hydroxide: Made by Deshan Caoda Co., Ltd.

Hydroxycarboxylic acid (salt)

‧ Citric acid (C ₆ H ₈ O ₇ ): manufactured by Komatsuya Chemical Co., Ltd.

"1-Hydroxyethane-1,1-diphosphonic acid (salt)"

‧ 1-Hydroxyethane-1,1-diphosphonic acid (C ₂ H ₈ O ₇ P ₂ ) (in the table, disclosed as hydroxyethane diphosphonic acid): Feliox 115A (trade name), Lion King Co., Ltd. system.

<Cleanse (C)>

‧ Concentrated sulfuric acid: EL grade reagent (purity of sulfuric acid 96% by mass), manufactured by Kanto Chemical Co., Ltd.

‧ Hydrogen peroxide water: EL grade reagent (hydrogen peroxide purity 30% by mass), manufactured by Kanto Chemical Co., Ltd.

‧ Concentrated hydrochloric acid (comparative product of sulfuric acid): EL grade reagent (purity of hydrochloric acid 35 mass%), manufactured by Kanto Chemical Co., Ltd.

(Preparation Example 1) Modification of detergent A-1 (corresponding to detergent (A))

According to the composition of Table 1, each raw material was dispersed in water to prepare a detergent A-1. The amount of blending in the table is a pure content equivalent (the same afterwards) unless otherwise specified.

(Preparation Example 2) Modulation of detergent A'-1 (Comparative product of detergent (A))

The detergent A'-1 was prepared according to the composition of Table 1, and each raw material was dispersed in water.

(Preparation Example 3) Modulation of detergent B-1 (corresponding to detergent (B))

According to the composition of Table 2, each raw material was dispersed in water to prepare a detergent B-1.

(Preparation Example 4) Modulation of detergent B'-1 (Comparative product of detergent (B))

According to the composition of Table 2, each raw material was dispersed in water to prepare a detergent B'-1.

(Preparation Example 5) Modification of detergent C-1 (corresponding to detergent (C))

According to the composition of Table 3 (however, the purity of sulfuric acid in the composition was 77% by mass, and the purity of hydrogen peroxide was 6% by mass), and each raw material was mixed to prepare a detergent C-1.

(Preparation Example 6) Modulation of detergent C'-1 (Comparative product of detergent (C))

According to the composition of Table 3 (however, the purity of hydrochloric acid in the composition is 28% by mass, the purity of hydrogen peroxide is 6% by mass), and the raw materials are mixed to prepare a wash. Detergent C'-1.

(Preparation Example 7) Modification of detergent C-2 (corresponding to detergent (C))

According to the composition of Table 3 (however, the purity of sulfuric acid in the composition was 86% by mass, and the purity of hydrogen peroxide was 3% by mass), and each raw material was mixed to prepare a detergent C-2.

(evaluation method of cleanliness)

In a 1000-level environment (management of particles of a size of 0.5 μm or more on the surface of the substrate, one cubic 呎 of 1000 or less in a clean room) is washed by a washing method of each example at a number of revolutions of 1000 rpm. The semiconductor substrate is rotated and dried (spin dry). The wafer surface inspection apparatus Candela CS10 (manufactured by KLA Tencor Co., Ltd.) was used to measure the number of particles (residual particles) of 0.5 μm or more remaining on the surface of the dried semiconductor substrate in a 1000-stage atmosphere. The number of residual particles measured was classified in the following evaluation criteria to evaluate the cleanliness.

<Evaluation criteria>

1 point: The number of residual particles is more than 10,000 pieces/piece.

2 points: The number of residual particles is more than 1000/piece, and 10,000/piece or less.

3 points: The number of residual particles is more than 500/piece, and 1000/piece or less.

4 points: The number of residual particles is more than 200 pieces/piece, and 500 pieces/piece or less.

5 points: The number of residual particles is more than 100 pieces/piece, and 200 pieces/piece or less.

6 points: The number of residual particles is 100 pieces/piece or less.

(Production of Semiconductor Substrate I)

The sapphire block was sliced to obtain the original plate. The obtained original plate was fixed to a polishing jig (wax fixing method) by a wax (hot melt adhesive-based adhesive), and subjected to a grinding treatment using a tannic acid gel belonging to an abrasive, and a diameter of 4 吋 (10 cm) was obtained. Semiconductor substrate 1. In the grinding process, a single-side polishing machine is used as the grinding machine.

(Production of Semiconductor Substrate II)

The sapphire block was sliced to obtain the original plate. The obtained original plate was embedded and fixed in a ceramic plate (fitting fixing method), and subjected to a grinding treatment using a tannic acid gel belonging to an abrasive, and a semiconductor substrate II having a diameter of 4 吋 (10 cm) was obtained. In the grinding process, a single-side polishing machine is used as the grinding machine.

(Examples 1, 4, Comparative Examples 11 to 12, 15 to 16)

The semiconductor substrate of the type shown in Tables 4 and 5 was immersed in 10L of the "first cleaning operation detergent" in Tables 4 and 5, and ultrasonic waves were applied to the detergent (50 ° C) for 10 minutes. (Frequency 36 kHz) (first cleaning operation).

10L of the "second cleaning operation detergent" in Tables 4 and 5 was made 130 ° C, and the semiconductor substrate which had been washed by the first cleaning operation was immersed therein for 10 minutes (second cleaning operation) ).

The cleanliness of the semiconductor substrate which had been washed by the second cleaning operation was evaluated, and the results are shown in Tables 4 and 5.

(Examples 2 to 3, Comparative Examples 13 to 14, 17 to 18)

The washing liquid was prepared by diluting the "first washing operation detergent" in Tables 4 and 5 to 20 times by pure water, and the first washing was performed using the washing liquid 10 L (50 ° C). The semiconductor substrate was washed in the same manner as in Example 1 except for the operation. Evaluate the cleanliness of the cleaned semiconductor substrate and compare the results Shown in Table 4 and Table 5.

(Examples 5 to 6)

In the same manner as in the first embodiment, the semiconductor substrate of the type shown in Table 4 was washed by the first cleaning operation and the second cleaning operation.

The semiconductor substrate which has been cleaned by the second cleaning operation was immersed in the "third cleaning operation detergent" 10L in Table 4, and ultrasonic waves were applied to the cleaning liquid (50 ° C) for 10 minutes (frequency 36 kHz) (third cleaning operation).

10 L of the "fourth washing operation detergent" in Table 4 was made 130 ° C, and the semiconductor substrate which had been washed by the third washing operation was immersed therein for 10 minutes (fourth washing operation).

The cleanliness of the semiconductor substrate which had been washed by the fourth cleaning operation was evaluated, and the results are shown in Table 4.

(Examples 7 to 8)

In the same manner as in the second embodiment, the semiconductor substrate of the type shown in Table 4 was washed by the first cleaning operation and the second cleaning operation.

The "third cleaning operation detergent" in Table 4 was diluted to 20 times by pure water to prepare a cleaning liquid, and the semiconductor substrate which had been washed by the second cleaning operation was immersed in the cleaning. In the liquid 10 L (50 ° C), ultrasonic waves were applied to the washing liquid for 10 minutes (frequency 36 kHz) (third washing operation).

10 L of the "fourth washing operation detergent" in Table 4 was made 130 ° C, and the semiconductor substrate which had been washed by the third washing operation was immersed therein for 10 minutes (fourth washing operation).

The cleanliness of the semiconductor substrate which had been washed by the fourth cleaning operation was evaluated, and the results are shown in Table 4.

(Examples 9 to 10)

The third cleaning operation was carried out by diluting the "third cleaning operation detergent" in Table 4 to 20 times with pure water to prepare a cleaning liquid, and using the cleaning liquid 10 L (50 ° C). The semiconductor substrate was washed in the same manner as in Example 5. The cleanliness of the semiconductor substrates which had been washed was evaluated, and the results are shown in Table 4.

(Examples 11 to 12)

The same procedure as in Example 7 was carried out except that the "cleaning agent for the third washing operation" in Table 4 was not diluted to prepare a washing liquid, and the third washing operation was carried out using the washing liquid 10 L (50 ° C). The semiconductor substrate is washed. The cleanliness of the semiconductor substrates which had been washed was evaluated, and the results are shown in Table 4.

(Examples 13 to 14)

The semiconductor substrate was washed in the same manner as in Examples 9 to 10 except that the detergent C-1 was changed to the detergent C-2. The cleanliness of the semiconductor substrates which had been washed was evaluated, and the results are shown in Table 4.

(Example 15)

The semiconductor substrate was washed in the same manner as in Example 7 except that the detergent C-1 was changed to the detergent C-2. The cleanliness of the semiconductor substrates which had been washed was evaluated, and the results are shown in Table 4.

(Comparative examples 1 to 2)

The semiconductor substrate was washed in the same manner as in Example 1 except that the second cleaning operation was not performed.

The cleanliness of the semiconductor substrates which have been washed was evaluated, and the results are shown in Table 5.

(Comparative examples 3 to 4)

The semiconductor substrate was washed in the same manner as in Example 2 except that the second cleaning operation was not performed.

The cleanliness of the semiconductor substrates which have been washed was evaluated, and the results are shown in Table 5.

(Comparative examples 5 to 6)

10 L of "first cleaning operation detergent" in Table 5 was made into 130 ° C, and the semiconductor substrate of the type shown in Table 5 was immersed therein for 10 minutes. That is, in Comparative Examples 5 to 6, the first cleaning operation in the first embodiment was omitted. The cleanliness of the semiconductor substrates which have been washed was evaluated, and the results are shown in Table 5.

(Comparative examples 7 to 8)

10 L of "first cleaning operation detergent" in Table 5 was made into 130 ° C, and the semiconductor substrate of the type shown in Table 5 was immersed for 10 minutes (first cleaning operation).

The semiconductor substrate which has been washed by the first cleaning operation is immersed in the "second cleaning operation detergent" 10L in Table 5, and the ultrasonic wave is applied to the detergent (50 ° C) for 10 minutes (frequency 36 kHz) (second cleaning operation).

The cleanliness of the semiconductor substrate which had been washed by the second cleaning operation was evaluated, and the results are shown in Table 4.

(Comparative examples 9 to 10)

A cleaning solution was prepared by diluting the "second cleaning operation detergent" in Table 5 by 20 times with pure water, and the second cleaning operation was performed using the cleaning liquid 10L, and preparation and comparison were carried out. The semiconductor substrate is washed in the same manner. The cleanliness of the semiconductor substrates which have been washed was evaluated, and the results are shown in Table 5.

(Comparative Example 19)

The semiconductor substrate 1 was washed by the following method.

First, the semiconductor substrate was immersed in 10 L of acetone (EL-based reagent, manufactured by Kanto Chemical Co., Ltd.), and ultrasonic waves were applied to acetone at 25 ° C for 10 minutes (first solvent washing).

The semiconductor substrate which had been washed by the first solvent was immersed in 10 L of isopropyl alcohol (EL-based reagent, manufactured by Kanto Chemical Co., Ltd.), and ultrasonic waves were applied thereto at 25 ° C for 5 minutes. The second solvent is washed).

The semiconductor substrate which has been washed by the second solvent is immersed in concentrated sulfuric acid (EL grade reagent, manufactured by Kanto Chemical Co., Ltd.): hydrogen peroxide water (EL grade reagent, manufactured by Kanto Chemical Co., Ltd.) The mixture of =4:1 was 10 minutes (120 ° C) for 10 minutes (sulphuric acid hydrogen peroxide (SPM) wash).

A semiconductor substrate that has been washed by SPM cleaning is immersed in ammonia water (EL-grade reagent, manufactured by Kanto Chemical Co., Ltd.): hydrogen peroxide water (EL-grade reagent, manufactured by Kanto Chemical Co., Ltd.): water = Mix 1:1:5 in 10 L (80 ° C) for 5 minutes (Ammonia Hydrogen Peroxide Water (APM) wash).

The semiconductor substrate which has been washed by APM washing is immersed in hydrofluoric acid (EL grade reagent, manufactured by Kanto Chemical Co., Ltd.): water mixture of 1:5 (10 ° C) for 5 minutes (thin) Hydrofluoric acid (DHF) wash).

A semiconductor substrate that has been washed by DHF washing is immersed in concentrated hydrochloric acid (EL-based reagent, manufactured by Kanto Chemical Co., Ltd.): hydrogen peroxide water (EL-based reagent, manufactured by Kanto Chemical Co., Ltd.): water The mixture of =1:1:5 was washed in 10 L (25 ° C) for 5 minutes (hydrogen peroxide water (HPM)).

When evaluating the cleanliness of the HPM-cleaned semiconductor substrate, The evaluation was 2 points (the number of residual particles was 2000).

(Comparative Example 20)

The semiconductor substrate was cleaned in the same manner as in Comparative Example 19 except that the semiconductor substrate I was replaced with the semiconductor substrate II. When the cleanliness of the semiconductor substrate which had been washed was evaluated, it was evaluated as 2 points (the number of residual particles was 3,500).

As shown in Table 4, the cleanliness of Examples 1 to 12 to which the present invention was applied was evaluated to be 3 or more. Among them, in Examples 1 to 4 which did not have the third to fourth cleaning operations, the examples 5 to 12 having the third to fourth cleaning operations as a whole improved the cleanliness.

Compared with Examples 1 and 5, detergent A-1 was used in the first cleaning operation. Further, in Example 9 in which the detergent B-1 was used in the third cleaning operation, the cleanness of the semiconductor substrate 1 was further improved.

Compared with Examples 2 and 12, Example 7 using the detergent B-1 in the first cleaning operation and the third cleaning operation can further improve the cleanliness of the semiconductor substrate II.

As shown in Table 5, the cleanliness of Comparative Examples 1 to 6 in which only the operation of washing with the detergent A-1, the detergent B-1 or the detergent C-1 was performed was evaluated as 1 minute.

The cleanliness of Comparative Examples 7 to 10 in which the detergent C-1 was used in the first washing operation and the detergent A-1 or the detergent B-1 in the second washing operation was evaluated as 1 minute.

Comparative Examples 11 to 14 in which the detergent C'-1 was used in the second cleaning operation, and Comparative Example 15 in which the detergent A'-1 or the detergent B'-1 was used in the first cleaning operation The cleanliness of 18 was evaluated to be 2 or less.

Comparative Examples 19 to 20 are conventional methods for cleaning a semiconductor substrate, and were combined with solvent cleaning (first and second solvent cleaning) and RCA cleaning (SPM cleaning - HPM cleaning). The cleanliness of Comparative Examples 19 to 20 was evaluated as 2 points.

From these results, it is understood that the degree of cleanliness of the semiconductor substrate can be further improved by applying the present invention.

Claims (6)

A method for cleaning a semiconductor substrate, comprising: a first cleaning operation for cleaning a semiconductor substrate on which a polishing process has been performed using a cleaning agent (A) or a cleaning agent (B); and a second cleaning a net operation of cleaning the semiconductor substrate by using the following cleaning agent (C) after the first cleaning operation; and a detergent (A): a liquid containing a hydrocarbon, a glycol ether, and a surfactant Detergent; detergent (B): an alkali metal hydroxide, one or more selected from the group consisting of hydroxycarboxylic acids and salts thereof, and selected from 1-hydroxyethane-1,1-diphosphonic acid One or more liquid detergents of the salt thereof; and a detergent (C): a liquid detergent containing sulfuric acid and hydrogen peroxide and having a sulfuric acid concentration of 50% by mass or more. The method for cleaning a semiconductor substrate according to claim 1, further comprising: a third cleaning operation of reusing the detergent (A) or the detergent (B) after the second cleaning operation The semiconductor substrate and the fourth cleaning operation are performed, and after the third cleaning operation, the cleaning agent (C) is reused to wash the semiconductor substrate. A method of cleaning a semiconductor substrate according to claim 2, wherein said detergent (A) is used in said first cleaning operation, and said detergent (B) is used in said third cleaning operation. The method for cleaning a semiconductor substrate according to claim 2, wherein the first The detergent (B) is used in the washing operation, and the detergent (B) is used in the third washing operation. The method of cleaning a semiconductor substrate according to claim 1, wherein the semiconductor substrate is a single crystal sapphire substrate. A method of manufacturing a semiconductor substrate, comprising: a cleaning step of cleaning a semiconductor substrate by a method of cleaning a semiconductor substrate according to any one of claims 1 to 5.