TWI532834B - Method for cleaning semiconductor substrate and detergent for two-component semiconductor substrate - Google Patents

Description

Method for cleaning semiconductor substrate and detergent for two-component semiconductor substrate

The present invention relates to a method for cleaning a semiconductor substrate and a detergent for a two-component type semiconductor substrate. More specifically, the present invention relates to a method for cleaning a semiconductor substrate in a mixed liquid exhibiting a specific pH value obtained by using a foaming agent component containing a carbonate and a foaming auxiliary component containing an acidic compound. . Further, in more detail, the present invention relates to a two-component type semiconductor substrate cleaning agent comprising a foaming agent component containing a carbonate and a foaming auxiliary component containing an acidic compound.

The manufacturing steps of the semiconductor element (semiconductor device) include various steps such as a lithography step, an etching step, and an ion implantation step. After the completion of each step and before proceeding to the next step, a cleaning treatment is performed to remove and remove a residue such as a residue or other impurities remaining on the surface of the substrate to clean the surface of the substrate.

As a conventional washing treatment method, a mixed solution of concentrated sulfuric acid and hydrogen peroxide (hereinafter referred to as SPM as appropriate) is used, and the resist residue, fine particles, metal, natural oxide film, and the like are peeled off and washed. In this method, although the peeling property of the deposit is excellent, the oxidizing power of the treatment liquid is too strong, and the gate insulating film or the substrate itself composed of a high-k material or the like may be damaged during the treatment. . In view of the current actual situation in which the miniaturization of semiconductor devices is progressing, even if such damage occurs locally, it causes a deterioration in electrical characteristics. Further, the method using SPM sometimes has a risk of the chemical itself or an imminent temperature rise, and thus is not a satisfactory method from the viewpoint of work safety.

Therefore, as one of the cleaning techniques for reducing the influence of the gate insulating film, the substrate, and the like, and the safety is excellent, for example, the following method for cleaning the ash residue is proposed: in the case of a carbon dioxide atmosphere, the use of carbonic acid Ammonium, an aqueous solution having a pH of 7 or more and less than 8.6 (Patent Document 1).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent No. 4017402

On the other hand, in recent years, in the ion implantation step (ion implantation) which is one of the manufacturing processes of the semiconductor element, the amount of ion implantation tends to increase. It is known that at this time, the ion-implanted resist is carbonized and crosslinked, and the outermost surface is deteriorated. Therefore, it is difficult to completely peel off the chemical by using a chemical or the like.

There is an increasing demand for high reliability of semiconductor devices, in which the desire for cleaning of the surface of the substrate is gradually becoming stricter, and it is desired to develop more efficient impurities including ion-implanted resist as described above. Washing method.

The inventors of the present invention have studied the peeling property of the above-described ion-implanted resist or the like using the cleaning liquid used in the cleaning method described in Patent Document 1, and as a result, it is not always possible to obtain a sufficiently satisfactory result. Further improvement is needed.

In view of the above circumstances, an object of the first aspect of the present invention is to provide a method for cleaning a semiconductor substrate which can damage impurities, particularly ions, on the surface of the semiconductor substrate without damaging the gate insulating film or the substrate. The deposit such as the injected resist is efficiently peeled off, and the safety is further excellent.

Further, in view of the above circumstances, an object of the second aspect of the present invention is to provide a two-component type semiconductor substrate cleaning agent which can damage the surface of the semiconductor substrate without damaging the gate insulating film or the substrate. The deposit such as a resist which is ion-implanted is efficiently peeled off, and the safety is further excellent.

The inventors of the present invention have conducted an effort to study the cleaning liquid used in the cleaning of the semiconductor substrate, and have found that the substrate is treated by using a detergent containing a specific component and a mixed solution containing a specific component. Get the desired effect.

That is, the inventors have found that the above problems can be solved by the following configuration.

<1> A method of cleaning a semiconductor substrate, wherein a foaming agent component and a foaming auxiliary component are supplied to a semiconductor substrate, and the semiconductor substrate is washed in a mixed solution of the foaming agent component and the foaming auxiliary component. The foaming agent component contains a carbonate, the foaming assistant component contains an acidic compound, and the pH of the mixed solution is less than 7.5.

The method for cleaning a semiconductor substrate according to the above aspect, wherein the semiconductor substrate is immersed in any one of the two components of the foaming agent component and the foaming assistant component, and then the Among the two ingredients The other mixture is added to the component impregnated with the semiconductor substrate to obtain the above mixture.

The method for cleaning a semiconductor substrate according to the above aspect, wherein the semiconductor substrate is immersed in the foaming agent component, and then the foaming auxiliary component is added to obtain the above-mentioned Mixture.

The method for cleaning a semiconductor substrate according to any one of the above aspects, wherein the foaming agent component and/or the foaming assistant component contains a surfactant.

The method of cleaning a semiconductor substrate according to the item <4>, wherein the surfactant is a nonionic surfactant.

The method for cleaning a semiconductor substrate according to any one of the items 1 to 5, wherein the carbonate is selected from the group consisting of ammonium carbonate, ammonium hydrogencarbonate, sodium hydrogencarbonate, sodium carbonate, A carbonate in a group consisting of potassium carbonate, potassium hydrogencarbonate, cesium carbonate, cesium carbonate, lithium carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, cesium carbonate, amine bismuth carbonate, and cesium carbonate.

The method for cleaning a semiconductor substrate according to any one of the above aspects, wherein the acidic compound is selected from the group consisting of sulfuric acid, nitric acid, boric acid, phosphoric acid, formic acid, acetic acid, and propionic acid. , benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid , tartaric acid, citric acid, lactic acid, glycine, alanine, aspartic acid, glutamic acid, amino methanesulfonic acid, taurine, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid and A compound in a group consisting of aminosulfonic acids.

The method for cleaning a semiconductor substrate according to any one of the above aspects, wherein the concentration of the carbonate in the mixed solution is from 0.1% by weight to 30% by weight.

The method for cleaning a semiconductor substrate according to any one of the above-mentioned item, wherein the foaming agent component and/or the foaming assistant component contains an oxidizing agent.

The method for cleaning a semiconductor substrate according to any one of the above items, wherein the temperature in the mixed solution is from 25 ° C to 80 ° C.

The method of cleaning a semiconductor substrate according to any one of the items of the present invention, wherein the semiconductor substrate has a resist on a surface thereof.

<12> The method for cleaning a semiconductor substrate according to the item <11>, wherein the resist is a resist to which ion implantation is performed.

<13> A method for producing a semiconductor device, comprising the step of cleaning the semiconductor substrate according to any one of the items <1> to <12>.

<14> A detergent for a two-component type semiconductor substrate, comprising a foaming agent component and a foaming auxiliary component which are mixed and used when the semiconductor substrate is washed, wherein the foaming agent component contains a carbonate, and the foaming aid The agent component contains an acidic compound, and the foaming agent component and/or the foaming assistant component further contains a surfactant, and a pH of the mixed solution of the foaming agent component and the foaming assistant component is less than 7.5.

<15> The detergent for a two-component type semiconductor substrate according to Item <14>, wherein the surfactant is a nonionic surfactant.

<16> The detergent for a two-component type semiconductor substrate according to Item <14>, wherein the carbonate is selected from the group consisting of ammonium carbonate, ammonium hydrogencarbonate, sodium hydrogencarbonate, sodium carbonate, and potassium carbonate. a carbonate in a group consisting of potassium hydrogencarbonate, cesium carbonate, cesium carbonate, lithium carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, cesium carbonate, amine bismuth carbonate, and cesium carbonate.

The two-package type semiconductor substrate cleaning agent according to any one of the above-mentioned items, wherein the acidic compound is selected from the group consisting of sulfuric acid, nitric acid, boric acid, phosphoric acid, formic acid, acetic acid, Propionic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, Malic acid, tartaric acid, citric acid, lactic acid, glycine, alanine, aspartic acid, glutamic acid, aminomethanesulfonic acid, taurine, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, ethane a compound in a group consisting of a sulfonic acid and an aminosulfonic acid.

The detergent for a two-component type semiconductor substrate according to any one of the above-mentioned items, wherein the concentration of the carbonate in the mixed solution is from 0.1 wt% to 30 wt%. .

The two-component type semiconductor substrate cleaning agent according to any one of the above-mentioned items, wherein the foaming agent component and/or the foaming auxiliary component further contains an oxidizing agent.

The two-component type semiconductor substrate cleaning agent according to any one of the above-mentioned items, wherein the surfactant is a polyoxyalkylene type nonionic surfactant.

The two-component type semiconductor substrate cleaning agent according to any one of the above-mentioned items, wherein the pH of the mixed liquid is less than 7.

The two-component type semiconductor substrate cleaning agent according to any one of the above-mentioned item, wherein the foaming agent component or the surfactant in the foaming auxiliary component is the surfactant. The content is 0.0001 wt% to 10 wt%.

The two-component type semiconductor substrate cleaning agent according to any one of the above-mentioned items, wherein the foaming agent component or the foaming auxiliary component contains the oxidizing agent. It is from 0.01 wt% to 20 wt%.

The two-component type semiconductor substrate cleaning agent according to any one of the items of the present invention, wherein the foaming agent component has a pH of 7.5 to 12.

According to the first aspect of the present invention, there is provided a method of cleaning a semiconductor substrate which can damage impurities, particularly ion-implanted resist, adhering to the surface of the semiconductor substrate without damaging the gate insulating film or the substrate. The attachment is efficiently detached and the safety is superior.

According to the second aspect of the present invention, it is possible to provide a two-component type semiconductor substrate cleaning agent which can impair impurities, particularly ion implantation, adhering to the surface of the semiconductor substrate without damaging the gate insulating film or the substrate. Adhesives such as etchants are peeled off efficiently, and safety is more excellent.

Hereinafter, a method of cleaning a semiconductor substrate according to a first aspect of the present invention and a detergent for a two-package type semiconductor substrate according to a second aspect of the present invention will be described in detail.

In the method for cleaning a semiconductor substrate according to the first aspect of the present invention, the foaming agent component and the foaming auxiliary component are supplied to the semiconductor substrate, and the semiconductor substrate is formed in a mixed solution of the foaming agent component and the foaming assistant component. Wash. The foaming agent component contains a carbonate, and the foaming aid component contains an acidic compound, and the pH of the mixed liquid shows less than 7.5. In this method, carbon dioxide (CO ₂ ) is generated in the mixed solution by mixing the two components in a specific pH value, and impurities adhering to the surface of the substrate are mainly caused by the action of the carbon dioxide and the acidic compound ( The attached matter is peeled off and removed. In particular, by performing a treatment of immersing the substrate in the blowing agent component for a specific period of time and then adding the foaming auxiliary component, the impurities can be more effectively peeled off and removed. Further, in the above Patent Document 1, it is necessary to perform cleaning in a carbon dioxide atmosphere, and the cleaning method according to the first aspect of the present invention does not particularly depend on the conditions of the gas environment, and can efficiently remove and remove impurities, and is excellent in versatility. .

The detergent for a two-package type semiconductor substrate according to a second aspect of the present invention is a foaming agent component containing a carbonate and a foaming auxiliary component containing an acidic compound, and is mixed while the semiconductor substrate is washed. The detergent used. Further, the foaming agent component and/or the foaming assistant component contains a surfactant, and the pH of the mixed solution of the foaming agent component and the foaming assistant component is less than 7.5. In the detergent, the carbon dioxide (CO ₂ ) is formed from the carbonate in the mixed solution obtained by mixing the foaming agent component and the blowing agent auxiliary component, and is mainly adhered by the action of the carbon dioxide and the acidic compound. The impurities (attachments) on the surface of the substrate are peeled off and removed.

Hereinafter, the reason why the pH of the mixed liquid in the first aspect of the present invention and the second aspect of the present invention is preferably less than 7.5 will be described. The pKa of the carbonate is 6.3 to 6.5 (pKa1) and 10.2 to 10.4 (pKa2), and is represented by the following formula.

CO ₃ ^2- +H ⁺ →HCO ₃ ^- →(1) pKa2

HCO ₃ ^- +H ⁺ →H ₂ CO ₃ →(2) pKa1

Further, carbon dioxide is generated by (2) a reaction of H ₂ CO ₃ →H ₂ O+CO ₂ (g) ↑. Generally, the so-called pKa refers to a pH at which a chemical species on both sides of a chemical reaction formula exists at 1:1. It is also known that a pH difference of 1 from the pKa means that the presence ratio of the chemical species on the right side and the left side is 10 times different. If the terms of (2) above, refers to the pH = 6.3 - 6.5, HCO ₃ ^- and H ₂ CO ₃ is present in equal amounts, while a pH = _{5.3 ~ 5.5 (pKa1-1) HCO 3} - and H ₂ CO _{3 is present} in a ratio of 1:10, and when pH = 7.3 to 7.5 (pKa1 + 1), HCO ₃ ^- and H ₂ CO ₃ are present in a ratio of 10:1. If the presence of the carbonate which contributes to foaming is increased, the pH value is 7.5 or more, and the foaming reaction which we expect may not be effectively caused.

First, the components (foaming agent component, foaming auxiliary component, and two-part type semiconductor substrate cleaning agent) used in the cleaning method of the present invention will be described in detail. Further, commercially available products may be used as the materials detailed below, or may be synthesized by a known method.

<Blowing agent ingredients>

(carbonate)

The blowing agent component contains a carbonate. This carbonate is a compound which generates carbon dioxide by the action of an acidic compound to be described later, and functions as a so-called decomposable foaming agent.

The carbonate to be used is not particularly limited as long as it is a carbonate compound which generates carbonic acid, and examples thereof include a normal salt, an acid salt (bicarbonate), a basic salt (carbonate hydroxide), and the like. For example, a carbonate or hydrogencarbonate of an alkali metal or an alkaline earth metal, or an ammonium carbonate salt can be mentioned. More specifically, examples of the carbonate include ammonium carbonate, ammonium hydrogencarbonate, sodium hydrogencarbonate, sodium carbonate, potassium carbonate, potassium hydrogencarbonate, cesium carbonate, cesium carbonate, lithium carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, and cesium carbonate. , amine bismuth carbonate or strontium carbonate, and the like. Further, an anhydrous salt, a hydrated salt or a mixture of such salts or the like can also be used. Among them, from the viewpoint of excellent peelability of the deposit and easy handling, ammonium hydrogencarbonate or ammonium carbonate is preferred, and ammonium carbonate is more preferred.

Further, the carbonate may be used alone or in combination of two or more.

The content of the carbonate in the foaming agent component is not particularly limited, and is preferably from 0.1% by weight to 80% by weight, more preferably from 0.1% by weight to 80% by weight based on the total amount of the foaming agent component. It is from 0.5 wt% to 50 wt%.

In addition, the content of the carbonate in the mixture of the foaming agent component and the foaming assistant component to be described later is preferably 0.1 wt% from the viewpoint of the total peeling property of the deposit. % to 30 wt%, more preferably 0.5 wt% to 30 wt%.

(solvent)

The blowing agent component may also contain a solvent as needed. The solvent to be used is not particularly limited as long as the carbonate is dissolved, and water is usually used. Further, an organic solvent may be contained within a range that does not impair the effects of the present invention (for example, Dimethyl sulfoxide (DMSO), Dimethylformamide (DMF), N- as a polar solvent. N-Methyl pyrrolidone (NMP), etc.).

The content of the solvent in the foaming agent component is not particularly limited, and is usually preferably from 1 wt% to 99.5 wt%, more preferably from 10 wt% to 99.0 wt%, based on the total amount of the foaming agent component.

The pH of the foaming agent component is not particularly limited, and is preferably 7.5 to 12.0, more preferably 8.0 to 11.0, from the viewpoint of further excellent stability of the foaming agent component and more excellent release property of the deposit.

(surfactant)

The blowing agent component may also contain a surfactant. By including the surfactant, the size of the bubbles generated by the carbon dioxide generated in the mixed solution of the foaming agent component and the foaming assistant component can be further controlled, and as a result, the peeling performance of the deposit such as the resist can be improved.

The surfactant to be used is not particularly limited, and examples thereof include a cationic surfactant, an amphoteric surfactant, an anionic surfactant, and a nonionic surfactant. In particular, the release property of the deposit is more excellent, and the effect of suppressing re-adhesion of impurities peeled off from the surface of the substrate to the surface of the substrate is more preferably a nonionic surfactant or an anionic surfactant. In view of view, a nonionic surfactant is particularly preferred. Further, as the surfactant, any of a linear chain and a branched shape can be used.

Examples of the cationic surfactant include a tetraalkylammonium salt, an alkylamine salt, a benzenedimethylammonium salt, an alkylpyridinium salt, an imidazolium salt, and the like.

Examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium alkyl diphenyl ether disulfonate, and sodium alkylnaphthalenesulfonate.

Examples of the amphoteric surfactant include a carboxybetaine, a sulfobetaine, an aminocarboxylate, an imidazoline derivative, and the like.

Examples of the nonionic surfactant include polyoxyethylene ethyl ether, polyoxyethylene ethyl phenyl ether, polyoxyethyl alcohol ester, sorbitan fatty acid ester, and polyoxyl extension. Ethyl sorbitan fatty acid ester, polyoxyethylene ethyl sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene ethyl glyceride fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxygen Ethyl alkylamine, polyoxyethylidene fatty acid decylamine, alkyl alkanolamine, acetylene glycol, polyoxyethylene ethylene adduct of acetylene glycol, and the like. Alternatively, a polyoxypropylidene compound having an oxygen-extended propyl structure in the above-exemplified compound may be exemplified.

Among them, a polyoxyalkylene type nonionic surfactant is preferred from the viewpoint of further excellent release properties of the adherend. Specific examples thereof include polyoxyalkylene alkyl ether, polyoxyalkylene alkylphenyl ether, polyoxyalkylene glycol fatty acid ester, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitol An anhydride fatty acid ester, a polyoxyalkylene fatty acid monoalkanolamine, a polyoxyalkylene fatty acid dialkylolamine or the like. More specifically, a surfactant having an alkyl group extending to an ethyl group or a propyl group may be mentioned.

Further, a preferred aspect of the polyoxyalkylene type nonionic surfactant is preferably a polyoxyalkylene type nonionic surfactant represented by the following formula (1).

R ² O-(R ¹ O) _p -H General formula (1)

In the formula (1), R ¹ represents an ethylidene group or a stretched propyl group, and p represents an integer of 2 or more (more preferably, it is preferably an integer of 30 or less, more preferably 10 or less). A plurality of R ^{1 's} may be the same or different.

R ² represents a hydrogen atom or an alkyl group (preferably having a carbon number of 1 to 20), and from the viewpoint of further excellent effects of the present invention, a hydrogen atom is preferred. Further, the alkyl group may have a substituent such as an amine group, and preferably does not contain a phenyl group as a substituent.

The preferred embodiment of the surfactant represented by the formula (1) is a polyoxyalkylene-type nonionic surfactant represented by the following formula (2) or (3).

HO-(EO) _x -(PO) _y -(EO) _z -H General formula (2)

HO-(PO) _x -(EO) _y -(PO) _z -H General formula (3)

In the general formula (2) and the general formula (3), EO represents an oxygen-extended ethyl group, and PO represents an oxygen-extended propyl group. x, y, and z each independently represent an integer of 1 or more (further, preferably an integer of 10 or less).

The content of the surfactant contained in the foaming agent component is not particularly limited, and is preferably 0.0001% by weight to 10% by weight based on the total amount of the foaming agent component from the viewpoint of further excellent peeling property of the adhering substance. More preferably, it is 0.001 wt% to 1 wt%.

Further, the content of the surfactant in the mixed solution of the foaming agent component and the foaming assistant component is not particularly limited, but is preferably 0.00005 wt% to 5 wt%, more preferably 0.0005 wt% to 0.5 wt%.

(oxidant)

The blowing agent component may also contain an oxidizing agent. By containing an oxidizing agent, the peelability of the deposit is further improved.

The oxidizing agent to be used is not particularly limited, and examples thereof include a peroxide (for example, hydrogen peroxide), a nitrate, a persulfate, a dichromate, a permanganate, and the like. Among them, hydrogen peroxide is preferred from the viewpoint of excellent peelability of the deposit and easy handling.

The content of the oxidizing agent contained in the foaming agent component is not particularly limited, and is preferably from 0.01% by weight to 20% by weight based on the total amount of the foaming agent component, from the viewpoint of further excellent peeling property of the adhering substance. Preferably, it is from 0.1 wt% to 20 wt%.

Further, the content of the oxidizing agent in the mixed solution of the foaming agent component and the foaming assistant component is not particularly limited, but is preferably 0.005 wt% to 10 wt%, more preferably 0.05 wt% to 10 wt%.

(alkaline compound)

The blowing agent component may also contain a basic compound. By containing a basic compound, the pH value can be easily adjusted, and stable foaming in the mixed solution can be achieved, and the peeling property of the deposit can be further improved.

The basic compound to be used is not particularly limited, and examples thereof include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide. The content of the basic compound in the foaming agent component is not particularly limited, but is preferably used to achieve the above pH value. Specifically, the content is preferably 0.0001% by weight to 10% by weight, more preferably 0.0001% by weight to 5% by weight based on the total amount of the blowing agent component.

<Foaming auxiliary ingredients>

(acidic compound)

The foaming aid component contains an acidic compound. The acidic compound refers to a compound which is directly or acidic in an aqueous solution. This compound acts on the above carbonate to form carbon dioxide and also contributes to the peelability of the deposit.

The acidic compound to be used is not particularly limited, and examples thereof include sulfuric acid, nitric acid, boric acid, phosphoric acid, formic acid, acetic acid, propionic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, and dibutyl. Acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, lactic acid, glycine, alanine, aspartic acid, glutamic acid , aminomethanesulfonic acid, taurine, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid or aminosulfonic acid, and the like.

Further, the acidic compound may be used alone or in combination of two or more.

Among them, a water-soluble organic acid is preferred from the viewpoint that the effect of the invention is more excellent, inexpensive, and easy to handle. A more preferred aspect is a water-soluble carboxylic acid having a carboxylic acid group. Preferable examples of the water-soluble carboxylic acid include a water-soluble aliphatic carboxylic acid. Further, a water-soluble aliphatic carboxylic acid having 1 to 6 carbon atoms is preferred. Particularly preferred are aliphatic monocarboxylic acids, dicarboxylic acids and tricarboxylic acids having 2 to 6 carbon atoms and having 2 to 6 carbon atoms.

Specific examples of the water-soluble carboxylic acid include propionic acid and antibiotics. Monocarboxylic acids such as ascorbic acid, lactic acid, gluconic acid, glucuronic acid, dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, malic acid, tartaric acid, phthalic acid, maleic acid, citric acid And other tricarboxylic acids.

The content of the acidic compound in the foaming auxiliary component is not particularly limited, and is preferably from 0.01% by weight to 50% by weight based on the total amount of the foaming auxiliary component, from the viewpoint of further excellent peeling property of the depositing agent. It is preferably from 1% by weight to 50% by weight, particularly preferably from 1% by weight to 25% by weight.

In addition, the content of the acidic compound in the mixture of the foaming agent component and the foaming assistant component to be described later is preferably 0.01 wt% from the viewpoint of the total peeling property of the deposit. %~30wt%, more preferably 0.01wt%~10wt%.

(solvent)

The foaming auxiliary component may contain a solvent as needed. The solvent to be used is not particularly limited as long as the acidic compound is dissolved, and water is usually used. Further, an organic solvent (for example, DMSO, DMF, NMP or the like as a polar solvent) may be contained in a range that does not impair the effects of the present invention.

The content of the solvent in the foaming auxiliary component is not particularly limited, and is usually preferably from 1% by weight to 99.5% by weight, and more preferably from 10% by weight to 99.0% by weight based on the total amount of the foaming auxiliary agent.

The pH of the foaming auxiliary component is not particularly limited, and is preferably 7.5 or less, and more preferably 5.0 or less from the viewpoint of further excellent stability of the foaming auxiliary component and excellent release property of the deposit. Further, the lower limit is not particularly limited, but is preferably 1.5 or more.

(other)

The above-mentioned surfactant, oxidizing agent, etc. may also be contained in a foaming adjuvant component. The kind and content of the compound to be used are the same as those of the above-mentioned blowing agent component.

<Two-component type semiconductor substrate cleaning agent>

A detergent for a two-package type semiconductor substrate according to a second aspect of the present invention comprises a foaming agent component containing a carbonate and a foaming auxiliary component containing an acidic compound, and the foaming agent component and/or the foaming assistant component A surfactant is contained therein, and when the semiconductor substrate is cleaned, the two are mixed and used.

The pH of the mixture was adjusted in a manner less than 7.5. When the pH of the mixed solution is 7.5 or more, the foaming of carbon dioxide is not sufficiently performed, and the peeling property of the deposit is inferior.

The pH of the mixed solution is preferably less than 7.0, more preferably 6.5 or less, and is preferably 2.0 or more, and more preferably 3.5 or more, from the viewpoint of more excellent peelability of the deposit. Further, the pH of the mixed solution sometimes changes with foaming, and it is preferred to maintain the pH within the above range throughout the treatment.

The mixing ratio by weight of the foaming agent component and the foaming auxiliary component (foaming agent component/foaming auxiliary component) is not particularly limited as long as the pH of the mixed solution is within the above range, and is operability and the like. In other words, it is preferably in the range of 0.01 to 100.

<Washing method>

In the method for cleaning a semiconductor substrate according to a first aspect of the present invention, the foaming agent component and the foaming auxiliary component are supplied to a semiconductor substrate, and a mixture of a foaming agent component and a foaming auxiliary component having a pH of less than 7.5 is displayed. A method of washing a semiconductor substrate in a liquid. Further, the method of washing the semiconductor substrate using the detergent for a two-component type semiconductor substrate according to the second aspect of the present invention is not particularly limited, and the above-described first aspect of the cleaning method of the present invention is preferred.

In general, since the resist (photoresist) after ion implantation is carbonized, it is difficult to remove and remove the chemical by the chemical, and the carbonized resist residue can be easily peeled off from the semiconductor substrate by the cleaning method. Remove. Further, the foaming agent component and the foaming agent auxiliary component are preferably used in the form of a so-called two-pack type detergent (two-part type semiconductor substrate detergent), and are used immediately before use.

The order of the method is detailed below.

As a general method for manufacturing a semiconductor device, first, a high dielectric constant material (for example, HfSiO ₄ , ZiO ₂ , or the like) is formed on a germanium substrate (for example, an ion-implanted n-type or p-type germanium substrate) by sputtering or the like. A gate insulating film made of, for example, ZiSiO ₄ , Al ₂ O ₃ , HfO ₂ , or La ₂ O ₃ ), or a gate electrode layer made of polysilicon or the like (step of forming an etched layer). Then, a resist is applied on the formed gate insulating film or gate electrode layer to form a specific pattern by photolithography. After the pattern is formed, an unnecessary portion of the resist is developed and removed (resist development step), and the resist pattern is used as a mask to dry-etch or wet-etch the non-mask region (etching step), Thereby, the gate insulating film, the gate electrode layer, and the like are removed. Then, in the ion implantation process (ion implantation step), the ionized p-type or n-type impurity element is implanted into the germanium substrate, and a p-type or n-type impurity implantation region is formed on the germanium substrate (so-called source/ Bungee area). Then, after the ashing treatment (ashing step) is performed as needed, a treatment for peeling off the resist film remaining on the substrate is performed.

The cleaning method of the first aspect of the present invention and the cleaning method of the detergent for a two-package type semiconductor substrate using the second aspect of the present invention are methods performed at the time of production of a semiconductor element, and can be carried out after any step. Specifically, it can be carried out, for example, after development of a resist, after dry etching, after wet etching, after ion implantation, after ashing, or the like. In particular, from the viewpoint of good releasability of the carbonized carbide by ion implantation, it is preferably carried out after the ion implantation step (ion implantation).

More specifically, it is preferable to apply the above-described cleaning method to the semiconductor substrate obtained by the following steps: preparing a semiconductor substrate on which an etched layer (gate insulating film and/or gate electrode layer) is formed (for example) a step of forming a p-type or n-type germanium substrate (an step of forming an etched layer), a step of forming a photoresist pattern on an upper portion of the etched layer (resist forming step), and selecting a photoresist pattern as an etch mask The step of etching the layer to be etched (etching step) and the step of performing ion implantation (ion implantation step).

Further, the ion implantation step can be carried out by a known method, and can be carried out, for example, at a dose of 10 ¹⁵ atoms/cm ² to 10 ¹⁸ atoms/cm ² using ions such as argon, carbon, ruthenium or arsenic.

Other suitable aspects of the cleaning method of the first aspect of the present invention and the cleaning method of the detergent for a two-package type semiconductor substrate using the second aspect of the present invention include the following methods: After the injecting step, the substrate is subjected to ashing treatment, or the removal of larger waste on the substrate or the removal of the bulk layer by the common cleaning solution is performed on the waste or various layers that are difficult to remove. The above washing method.

After the ashing treatment as described above, the cleaning method of the first aspect of the present invention or the cleaning method of the detergent for the two-package type semiconductor substrate using the second aspect of the present invention is carried out, even if the foaming agent is used. The component and the foaming auxiliary component do not contain an oxidizing agent, and a sufficient washing effect can be produced. When the oxidizing agent is not used in the washing method, the generation of the oxide film on the substrate is further suppressed, which is preferable. The ashing treatment can be carried out by a well-known method, and examples thereof include a method using a plasma gas.

In addition, the cleaning method can be carried out repeatedly on the same substrate. For example, by performing treatment such as washing twice or more (for example, two times, three times), it is possible to obtain a better effect than one wash.

(semiconductor substrate)

As the semiconductor substrate (substrate for semiconductor element) which is the object to be cleaned by the cleaning process, the semiconductor substrate of any of the above-described manufacturing steps can be used. The object to be cleaned is preferably a semiconductor substrate having a resist (especially a resist subjected to ion implantation (ion implantation)) on its surface. Further, by using the cleaning method according to the first aspect of the present invention or the detergent of the second aspect of the present invention, in addition to the above resist (or pattern resist), ashing may be performed from the surface. The substrate (residue residue) generated by the residue (ashing residue) or the residue (etch residue) generated during etching and other impurities (attachment) are peeled off and removed.

The semiconductor substrate used in the first aspect of the present invention and the second aspect of the present invention may have an insulating film such as a hafnium oxide film or a tantalum nitride film or a nitrogen portion on a part or the entire surface thereof in addition to the resist. TaO, TiN, Titanium Oxide (HfO ₂ ), La ₂ O ₃ , Al ₂ O ₃ , Polycrystalline, Doped (Arg, Carbon, antimony, arsenic, etc.).

In addition, the semiconductor substrate refers to a member made of a semiconductor material (for example, a germanium substrate), and is not limited to a plate-shaped substrate, and any shape thereof is included in the “semiconductor substrate” as long as it is a semiconductor material.

The resist deposited on the semiconductor substrate used in the first aspect of the present invention and the second aspect of the present invention is a known resist material, and examples thereof include a positive type, a negative type, and a positive-negative type resist. . Specific examples of the positive resist include vinyl cinnamate, cyclized polyisobutylene, azo novolak resin, and diazoketone-novolac resin. Further, specific examples of the negative resist include an azide-cyclopolyisoprene system, an azide-phenol resin system, and a chloromethylpolystyrene system. Further, specific examples of the positive-negative-purpose resist include poly(p-butoxycarbonyloxystyrene) and the like.

(washing order)

In the method for cleaning a semiconductor substrate according to the first aspect of the present invention, the foaming agent component and the foaming auxiliary component are supplied to the semiconductor substrate. Moreover, in the washing method using the detergent of the second aspect of the present invention, it is preferred to supply the foaming agent component and the foaming auxiliary component to the semiconductor substrate. The supply method is not particularly limited, and the foaming agent component and the foaming assistant component (the aspect A) can be simultaneously supplied to the semiconductor substrate. Further, the foaming agent component may be supplied to the semiconductor substrate to immerse the substrate in the component, and the foaming auxiliary component (the aspect B) may be supplied after a predetermined period of time. Further, the foaming aid component may be supplied to the semiconductor substrate to immerse the substrate in the component, and the foaming agent component (the aspect C) may be supplied after a predetermined period of time.

In view of the fact that the peeling property of the deposit is more excellent, it is preferred to immerse the semiconductor substrate in any one of the foaming agent component or the foaming assistant component for a specific period of time, and to add another one (state B or aspect C). . In particular, from the viewpoint of further improving the peeling property of the deposit and further reducing damage to the substrate or the gate insulating film, etc., it is preferable to add a foaming aid component after immersing the semiconductor substrate in the foaming agent component. Sample C). By immersing the semiconductor substrate in the foaming agent component for a specific period of time, the carbonate adheres to the vicinity of the deposit, so that the generated carbon dioxide contributes to the peeling and removal of the deposit.

The immersion time of the semiconductor substrate in the foaming agent component or the foaming assistant component is not particularly limited, and the longer the immersion time is, the more the component contained adheres to the periphery of the adherend such as the resist residue on the semiconductor substrate, and adheres thereto. The removal efficiency of the object is increased. From the viewpoint of improving the peeling property of the deposit, it is preferably 10 seconds or longer, more preferably 30 seconds or longer. Further, in terms of productivity and saturation of effects, it is preferably within 30 minutes.

The temperature of the foaming agent component or the foaming auxiliary component at the time of immersion is not particularly limited, and is preferably 25 to 80 ° C from the viewpoint of achieving excellent release property of the deposit and achieving stable foaming.

When a mixed liquid is produced by adding another unselected blowing agent component or a foaming auxiliary component to any one of a foaming agent component or a foaming auxiliary component impregnated with a semiconductor substrate, the additive component (foaming) The method of the component or the foaming auxiliary component may be added in one portion or in portions.

Further, in the above-described cleaning method, a component other than the foaming agent component and the foaming assistant component (for example, pure water) may be added together in a range that does not impair the effects of the invention.

The temperature (treatment temperature) of the liquid mixture of the foaming agent component and the foaming auxiliary component is not particularly limited, and the peeling property of the deposit is more excellent, and the damage to the substrate or the gate insulating film is further reduced. It is preferred to carry out temperature control so as to reach 25 ° C to 80 ° C, more preferably 30 ° C to 75 ° C. When the temperature of the mixed solution is too high, foaming of carbon dioxide may occur instantaneously to impair the peeling property and workability of the deposit, and if the temperature of the mixed liquid is too low, the removal of the deposit may take time.

Further, when a foaming aid component (or a foaming agent component) is added to a foaming agent component (or a foaming assistant component) impregnated with a semiconductor substrate as described above, it is preferred to set the temperature of the mixed solution. The mode is controlled within the above range to control the addition speed.

In the method for cleaning a semiconductor substrate according to the first aspect of the present invention, the pH of the mixed solution obtained by mixing the foaming agent component and the foaming auxiliary component is controlled to be less than 7.5. When the pH of the mixed solution is 7.5 or more, the foaming of carbon dioxide is not sufficiently performed, and the peeling property of the deposit is inferior.

The pH of the mixed solution is preferably less than 7.0, more preferably 6.5 or less, and is preferably 2.0 or more, and more preferably 3.5 or more, from the viewpoint of more excellent peelability of the deposit. Further, the pH of the mixed solution sometimes changes with foaming, and it is preferred to maintain the pH within the above range throughout the treatment.

In the method for cleaning a semiconductor substrate according to the first aspect of the present invention, the mixing ratio by weight of the foaming agent component to the foaming auxiliary component (foaming agent component/foaming auxiliary component) is as long as the pH of the mixed solution is in the above range The inside is not particularly limited, and is preferably in the range of 0.01 to 100 from the viewpoint of workability and the like.

After mixing the foaming agent component and the foaming assistant component, the semiconductor substrate may be immersed in the mixed solution for a specific period of time as needed. The immersion time is not particularly limited, and is preferably from 10 seconds to 5 minutes, more preferably from 30 seconds to 3 minutes, from the viewpoint of productivity and the like. The semiconductor substrate is immersed in the mixed solution, and the mixed solution may be stirred as needed.

After the completion of the above treatment, the semiconductor substrate is taken out from the mixed liquid, and if necessary, the surface may be washed with water or the like (washing step).

By the method of cleaning a semiconductor substrate according to the first aspect of the present invention or the method of cleaning a detergent for a two-package type semiconductor substrate according to the second aspect of the present invention, it is possible to remove and remove the chemical or the like by using a prior chemical or the like. The deposit such as the ion-coated resist is peeled off and removed from the surface of the semiconductor substrate. That is, the above-described cleaning method can be used as a method of peeling off a resist for removing and removing a resist remaining on a semiconductor substrate.

Further, a method of cleaning a semiconductor substrate according to a first aspect of the present invention or a method of cleaning a detergent for a two-package type semiconductor substrate using the second aspect of the present invention, and a method of using a conventional cleaning chemical, that is, an SPM solution In different cases, it is possible to suppress metal wiring such as aluminum or the like deposited on the surface of the semiconductor substrate, or a titanium nitride layer (TiN), a hafnium oxide layer (HfO ₂ ), or a hafnium oxide layer (La). ₂ O ₃ ) and other effects such as corrosion of the gate insulating film.

A method of manufacturing a semiconductor device according to a first aspect of the present invention is a method comprising the step of performing a cleaning step using the method for cleaning a semiconductor substrate according to the first aspect of the present invention, and specifically includes using the above-mentioned foaming agent component and hair A method of washing the foaming agent component. Further, the cleaning step by the cleaning method using the two-package type semiconductor substrate cleaning agent according to the second aspect of the present invention is preferably included in the method of manufacturing a semiconductor element.

This cleaning step can also be applied to the cleaning of a semiconductor substrate having a very small wiring width which cannot be applied by the conventional detergent, and the damage to a high dielectric constant (High-k) film or the like is also small, so that it can be suitably used for Manufacturing of electronic components such as liquid crystal displays (LCDs), memories, and central processing units (CPUs) that are smaller and more powerful. Further, it can be suitably used for the production of a semiconductor element of a porous material which is easily damaged, such as an ultra-low dielectric constant (Ultra-low-k) which is being developed as a new generation of an insulating film.

[Example]

Hereinafter, the first aspect of the present invention and the second aspect of the present invention will be described in detail, but the first aspect of the present invention and the second aspect of the present invention are not limited to the examples.

(production of sample 1)

The thickness of the resist on the wafer is 3000 The way to apply a universal resist (248 nm, KrF resist). Then, the resist-coated sample was prebaked (temperature: 200 ° C to 300 ° C). Thereafter, an ion implantation operation is performed. The ions were prepared by using As ions and setting the dose to 1E ^{15 to 16} atoms/cm ² .

(production of sample 2)

On the wafer, the thickness becomes 50 In the manner of forming an Al ₂ O ₃ layer, a TiN layer, an HfO ₂ layer or a La ₂ O ₃ layer, four kinds of wafers were prepared. The etching rate (ER) for each film was calculated from the difference in film thickness before and after the treatment using each of the liquids described later.

Practically, the etching rate is preferably less than 5 nm/min, more preferably less than 1 nm/min.

The surfactants W1 to W9 used in the examples described later are shown below.

A in W1 represents 3, b represents 5, and c represents a numerical value of 3.

A in W2 represents 4, b represents 2, and c represents a value of 4.

In W8, a represents 5, b represents 5, c represents 5, d represents 5, e represents 5, and f represents a numerical value of 5.

Further, "30% hydrogen peroxide" in Tables 1 to 12 indicates hydrogen peroxide water having a concentration of 30% by weight.

<Example A: Study of acidic compounds (Examples 1 to 19, Comparative Examples 1 to 5)

The foaming agent component and the foaming assistant component shown in the following Table 1 were used to evaluate the resist peeling property, handleability, metal layer, and influence on the substrate.

First, the prepared semiconductor substrate (sample 1, sample 2, or untreated tantalum wafer) was immersed in the foaming agent component for a specific time (3 minutes). The pH value (shown as the initial pH value) of the foaming agent component to be used is shown in Table 1.

Then, a foaming aid component was added to the foaming agent component, and the substrate was immersed in the mixed solution for 2 minutes. Thereafter, the substrate was taken out and the following evaluation was performed. Further, the pH value in the mixed solution is shown in Table 1 as the final pH value. The results obtained are shown in Table 1.

In addition, the processing temperature in Table 1 means the temperature in the mixed liquid, and the same meaning is also shown in Table 2 - Table 12 mentioned later.

The peeling property of the resist was evaluated based on the following criteria. In practical terms, it must not be ×.

"◎◎◎: The portion of the substrate surface (area: 3.0 μm × 3.0 μm) where the resist remains is less than 5%"

"◎◎: The portion where the resist remains on the surface of the substrate (area: 3.0 μm × 3.0 μm) observed by a microscope is 5% or more and less than 10%."

◎: The portion where the resist remains on the surface of the substrate (area: 3.0 μm × 3.0 μm) observed by a microscope is 10% or more and less than 30%.

"○: The portion where the resist remains on the surface of the substrate (area: 3.0 μm × 3.0 μm) observed by a microscope is 30% or more and less than 50%"

"△: 50% or more and less than 80% of the portion where the resist remains on the surface of the substrate (area: 3.0 μm × 3.0 μm) observed by a microscope"

"X: When the portion where the resist remains on the surface of the substrate (area: 3.0 μm × 3.0 μm) observed by a microscope is 80% or more", the operability was evaluated according to the following criteria.

"◎": no problematic blistering

"○": some bubbling

"△": the foaming is slightly intense

"X": Observed the practical use of violent foaming at a worrying level.

The values described in the column of "Doped Si-loss" in Table 1 are untreated using the inductively coupled plasma-mass spectrometry (ICP-MS, manufactured by SHIMADZU). The thickness of the wafer on the surface of the wafer (the thickness which was removed by washing) was measured and converted into a film thickness (nm). Practically, the value is preferably less than 1.0 nm.

In addition, the value described in the column of "Ox growth" in Table 1 is an oxidation formed on the surface of the wafer when an untreated tantalum wafer is used in Example A by an ellipsometer (manufactured by JAWoollam Co., Ltd., VASE). The value (nm) obtained by measuring the thickness of the ruthenium layer was measured. Practically, the value is preferably less than 1.0 nm.

In addition, in Table 1, "N.D" means that the etching rate is almost 0 (the same meaning is also shown in the following table). Further, in Table 1, "TMAH" used in the foaming agent component means tetramethylammonium hydroxide.

From Table 1, it was confirmed that the cleaning method of the present invention was carried out using various acidic compounds, and as a result, practically satisfactory resist peeling property and workability were obtained. Further, as a result of using the sample 2, it was found that the etching effect on the Al ₂ O ₃ layer, the TiN layer, the HfO ₂ layer, and the La ₂ O ₃ layer was hardly observed in the cleaning method of the present invention, and it was confirmed that even for These layers also do not cause damage. Further, it was found that the chipping of the surface of the substrate or the generation of the ruthenium oxide layer was also suppressed (less than 0.1 nm, respectively).

On the other hand, as shown in Comparative Example 1 and Comparative Example 2, when a conventionally known SPM or the like was used as the cleaning liquid, peeling of the resist was confirmed, but workability was impaired. Further, it was confirmed that the Al ₂ O ₃ layer, the TiN layer, the HfO ₂ layer, and the La ₂ O ₃ layer were etched to cause damage to each layer. Further, it was confirmed that the surface of the substrate was cut off or the ruthenium oxide layer was generated.

Further, in Comparative Example 4 in which the foaming agent component containing a carbonate was not used, and Comparative Example 5 in which the foaming auxiliary component containing an acidic compound was not used, it was confirmed that the resist peeling property was poor in the absence of one component. .

Further, when the pH of the mixture of the foaming agent component and the foaming assistant component was 7.5 or more as shown in Comparative Example 6, it was confirmed that foaming in the mixed liquid was not observed, and it was confirmed that the resist peeling property was also inferior.

<Example B: Study of carbonate (Example 20 to Example 25)>

The foaming agent component and the foaming auxiliary component shown in the following Table 2 were used, and washed in the same order as in the above-mentioned Example A, and various evaluations were performed. In Table 2, the initial pH value indicates the pH of the foaming agent component, and the final pH value indicates the pH of the mixed solution of the foaming agent component and the foaming assistant component.

As is apparent from Table 2, the cleaning method of the present invention was carried out using various carbonates, and as a result, practically satisfactory resist peeling property and workability were obtained. In addition, etching of various metal layers is hardly present, and the influence on the germanium wafer is hardly present.

<Example C: Study of washing sequence (Examples 26 to 32)>

Using the foaming agent component and the foaming auxiliary component shown in the following Table 3 and Table 4, various evaluations were performed in the method shown below.

First, the prepared semiconductor substrate (sample 1, sample 2, or untreated tantalum wafer) was immersed in the foaming agent component for a specific time shown in Table 3 and Table 4.

Then, a foaming auxiliary component was added to the foaming agent component, and the substrate was immersed in the mixed liquid for a specific time shown in Table 3 and Table 4. Then, the substrate was taken out and the following evaluation was carried out. The results are shown in Table 3 and Table 4. In Tables 3 and 4, the initial pH value indicates the pH of the foaming agent component, and the final pH value indicates the pH of the mixed solution of the foaming agent component and the foaming assistant component.

As shown in Table 3, it was confirmed that the resist peeling property was improved by extending the immersion time of the substrate in the mixed solution. In addition, etching of various metal layers is hardly present, and the influence on the germanium wafer is hardly present.

Further, as shown in Table 4, it was confirmed that the resist peeling property was improved by extending the immersion time of the substrate in the foaming agent component.

<Example D: Content analysis of various components used (Examples 33 to 42)>

The foaming agent component and the foaming auxiliary component shown in the following Tables 5 to 7 were used, and washed in the same order as in the above-mentioned Example A, and various evaluations were carried out. In Tables 5 to 7, the initial pH value indicates the pH of the foaming agent component, and the final pH value indicates the pH of the mixed solution of the foaming agent component and the foaming assistant component.

As shown in Table 5, Table 6, and Table 7, it was confirmed that the desired effect can be obtained even when the amount of the carbonate, TMAH, and acidic compound used is changed.

<Example E: Study on the content of oxidant (Examples 43 to 47)>

The foaming agent component and the foaming auxiliary component shown in the following Table 8 were used, and washed in the same order as in the above-mentioned Example A, and various evaluations were performed. In Table 8, the initial pH value indicates the pH of the foaming agent component, and the final pH value indicates the pH of the mixed solution of the foaming agent component and the foaming assistant component.

As shown in Table 8, it was confirmed that the desired effect can be obtained even when the amount of the oxidizing agent used is changed. In particular, it has been found that the resist releasability is improved by increasing the content of the oxidizing agent.

<Example F: Temperature Condition Study (Example 48 to Example 50)>

The foaming agent component and the foaming auxiliary component shown in the following Table 9 were used, and washed in the same order as in the above-mentioned Example A, and various evaluations were performed. In Table 9, the initial pH value indicates the pH of the blowing agent component, and the final pH value indicates the pH of the mixed solution of the blowing agent component and the foaming auxiliary component.

As shown in Table 9, it was confirmed that the desired effects of the present invention can be obtained even if the temperature conditions are changed between 20 ° C and 70 ° C. In particular, it has been found that the resist peelability is improved at 50 ° C or higher.

<Example G: Study of surfactants (Examples 51 to 62)>

The foaming agent component and the foaming auxiliary component shown in the following Table 10 were used, and washed in the same order as in the above-mentioned Example A, and various evaluations were performed. In Table 10, the initial pH value indicates the pH of the foaming agent component, and the final pH value indicates the pH of the mixed solution of the foaming agent component and the foaming assistant component.

In addition, the evaluation of the column of "reattachability" in Table 10 was performed based on the following criteria.

"○": When the surface of the wafer after the treatment was observed with an optical microscope, there was no reattachment of the exfoliated material.

"△": When the surface of the wafer after the treatment was observed with an optical microscope, the reattachment of the exfoliated material was slightly confirmed.

"X": When the surface of the wafer after the treatment was observed with an optical microscope, it was confirmed that a large amount of the peeled material reattached.

As shown in Table 10, it was found that in the cleaning method of the present invention, even when various surfactants are used, the desired effects can be obtained. Furthermore, "-" in Table 10 means that it is not implemented.

In particular, it has been confirmed that a polyoxyalkylene type nonionic surfactant (particularly, a surfactant represented by the formula (1)) has an excellent effect in terms of workability.

<Example H: Study on the content of surfactants (Examples 63 to 66)>

The foaming agent component and the foaming auxiliary component shown in the following Table 11 were used, and washed in the same order as in the above-mentioned Example A, and various evaluations were performed. In Table 11, the initial pH value indicates the pH of the foaming agent component, and the final pH value indicates the pH of the mixed solution of the foaming agent component and the foaming assistant component.

As shown in Table 11, it was found that in the cleaning method of the present invention, even when the amount of use of various surfactants is changed, the desired effect can be obtained.

<Example I: Application of Pre-Processing (Examples 67 to 68)>

The foaming agent component and the foaming auxiliary component shown below were washed in the same order as in the above-mentioned Example A, and various evaluations were performed. In Table 12, the initial pH value indicates the pH of the foaming agent component, and the final pH value indicates the pH of the mixed solution of the foaming agent component and the foaming assistant component.

In addition, this time, the germanium wafer used was a germanium wafer which was temporarily processed under the following conditions.

Example 68: A ruthenium wafer having an ion-implanted resist was treated by a DMSO solution by the above method to remove a bulk layer, and the following foaming agent component and foaming were used for the cured film remaining on the ruthenium wafer. The auxiliary ingredients are washed.

Example 69: Oxygen is formed into a plasma gas by ultraviolet light, and the ruthenium wafer having the ion-implanted resist is subjected to ashing treatment by the above method, and the following foaming agent component is used for the residue and The foaming auxiliary component is washed.

As is clear from Table 12, it was confirmed that the peeling property of the resist was further improved by performing the ashing treatment before the washing step of the present invention.

Claims (24)

A method for cleaning a semiconductor substrate, comprising: supplying a foaming agent component and a foaming auxiliary component to a semiconductor substrate, and cleaning the semiconductor substrate in a mixed solution of the foaming agent component and the foaming auxiliary component; The foaming agent component contains a carbonate, the foaming auxiliary component contains an acidic compound, and the pH of the mixed liquid is less than 7.5. The method for cleaning a semiconductor substrate according to claim 1, wherein the semiconductor substrate is immersed in any one of two components of the foaming agent component and the foaming assistant component, and then the two types are used. The other of the components is added to a component impregnated with a semiconductor substrate to obtain the above mixture. The method for cleaning a semiconductor substrate according to claim 1, wherein the semiconductor substrate is immersed in the foaming agent component, and then the foaming auxiliary component is added to obtain the mixed liquid. The method for cleaning a semiconductor substrate according to claim 1, wherein the foaming agent component and/or the foaming assistant component contains a surfactant. The method for cleaning a semiconductor substrate according to claim 4, wherein the surfactant is a nonionic surfactant. The method for cleaning a semiconductor substrate according to claim 1, wherein the carbonate is selected from the group consisting of ammonium carbonate, ammonium hydrogencarbonate, sodium hydrogencarbonate, sodium carbonate, potassium carbonate, potassium hydrogencarbonate, cesium carbonate, and cesium carbonate. , lithium carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, cesium carbonate, amine bismuth carbonate And carbonates in the group consisting of strontium carbonate. The method for cleaning a semiconductor substrate according to claim 1, wherein the acidic compound is selected from the group consisting of sulfuric acid, nitric acid, boric acid, phosphoric acid, formic acid, acetic acid, propionic acid, benzoic acid, glycolic acid, salicylic acid, Glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, lactic acid, glycine, a group consisting of alanine, aspartic acid, glutamic acid, aminomethanesulfonic acid, taurine, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, and aminosulfonic acid Compound. The method for cleaning a semiconductor substrate according to claim 1, wherein the concentration of the carbonate in the mixed solution is from 0.1% by weight to 30% by weight. The method for cleaning a semiconductor substrate according to claim 1, wherein the foaming agent component and/or the foaming assistant component contains an oxidizing agent. The method for cleaning a semiconductor substrate according to claim 1, wherein the temperature in the mixed solution is from 25 ° C to 80 ° C. The method of cleaning a semiconductor substrate according to claim 1, wherein the semiconductor substrate has a resist on a surface thereof. The method for cleaning a semiconductor substrate according to claim 11, wherein the resist is a resist that is ion implanted. A method of producing a semiconductor device, comprising the step of cleaning a semiconductor substrate according to any one of claims 1 to 12. A detergent for a two-component type semiconductor substrate, comprising a foaming agent component and a foaming auxiliary component which are mixed and used when the semiconductor substrate is washed, wherein the foaming agent component contains a carbonate, and the foaming auxiliary component contains The acidic compound, the foaming agent component and/or the foaming auxiliary component further contains a surfactant, and a pH of the mixed solution of the foaming agent component and the foaming assistant component is less than 7.5 and more than 4.6. The two-component type semiconductor substrate cleaning agent according to claim 14, wherein the surfactant is a nonionic surfactant. The two-component type semiconductor substrate cleaning agent according to claim 14, wherein the carbonate is selected from the group consisting of ammonium carbonate, ammonium hydrogencarbonate, sodium hydrogencarbonate, sodium carbonate, potassium carbonate, potassium hydrogencarbonate, cesium carbonate, A carbonate in a group consisting of cesium carbonate, lithium carbonate, magnesium carbonate, manganese carbonate, nickel carbonate, cesium carbonate, amine bismuth carbonate, and cesium carbonate. The two-component type semiconductor substrate cleaning agent according to claim 14, wherein the acidic compound is selected from the group consisting of sulfuric acid, nitric acid, boric acid, phosphoric acid, formic acid, acetic acid, propionic acid, benzoic acid, glycolic acid, and salicylate. Acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, lactic acid, glycine a group consisting of acid, alanine, aspartic acid, glutamic acid, aminomethanesulfonic acid, taurine, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, and aminosulfonic acid Compound in. The detergent for a two-component type semiconductor substrate according to claim 14, wherein the concentration of the carbonate in the mixed solution is from 0.1% by weight to 30% by weight. The two-component type semiconductor substrate cleaning agent according to claim 14, wherein the foaming agent component and/or the foaming auxiliary component further contains an oxidizing agent. The two-component type semiconductor substrate cleaning agent according to claim 14, wherein the surfactant is a polyoxyalkylene type nonionic surfactant. The two-component type semiconductor substrate cleaning agent according to claim 14, wherein the mixed solution has a pH of less than 7 and greater than 4.6. The detergent for a two-component type semiconductor substrate according to claim 14, wherein the content of the surfactant in the foaming agent component or the foaming assistant component is 0.0001% by weight to 10% by weight. The detergent for a two-component type semiconductor substrate according to claim 19, wherein a content of the oxidizing agent in the foaming agent component or the foaming assistant component is 0.01% by weight to 20% by weight. The two-package type semiconductor substrate cleaning agent according to any one of claims 14 to 23, wherein the foaming agent component has a pH of 7.5 to 12.