JP2009231354A - Cleaning liquid for semiconductor device and cleaning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide cleaning liquid for a semiconductor device, for removing stuck matters on the surface of a cleaning object such as photoresist, etching residuals, an antireflective coating and ashing residuals with low environment loads and without corroding an interlayer dielectric; and to provide a cleaning method for the semiconductor device using the cleaning liquid. <P>SOLUTION: The cleaning liquid for the semiconductor device contains an oxidant, a metal etchant, and a surfactant, and has a pH of 10-14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor device cleaning liquid and a cleaning method. Specifically, the present invention relates to a semiconductor device manufacturing process, and in particular, for removing photoresist, etching residue, antireflection film, ashing residue, and the like present on a substrate in all steps of semiconductor device manufacturing. And a semiconductor device cleaning method using the cleaning liquid.

  A semiconductor device such as a CCD or a memory is manufactured by forming a fine electronic circuit pattern on a substrate using a photolithography technique. Specifically, a resist film is applied on a laminated film such as a metal film (for example, copper), an interlayer insulating film, an antireflection film, or the like, which is a wiring material formed on the substrate, and a photolithography process / dry etching process is performed. It is manufactured after. The photoresist and antireflection film remaining after the photolithography process are dry ashed. Thereafter, a process of removing residues (etching residue, ashing residue, etc.) generated in the dry etching process and the dry ashing process and remaining on the wiring material and the interlayer insulating film material with a cleaning liquid is generally performed.

  In recent years, with higher performance of semiconductor devices, further miniaturization and higher speed of manufacturing have been demanded. Among them, reduction of cleaning time and improvement of cleaning technology in the semiconductor device manufacturing process are important issues. Yes. For example, an interlayer insulating film made of a low-k material is used to improve the performance of a semiconductor device. When the low-k material contains a porous (hole) for decreasing the k value, the contact area between the cleaning liquid and the low-k material becomes large due to the presence of holes during the cleaning process, and the cleaning liquid is removed during the cleaning process. As a result, the low-k material may be etched. This leads to a change in the shape of the device wiring, which is undesirable for device performance.

  Also, along with the thinning and high performance of semiconductor devices, the dry ashing process is not performed or is performed to reduce the damage during the manufacturing process on the wiring material, particularly the interlayer insulating film made of a low-k material. In recent years, the manufacturing process has changed to perform a light dry ashing process. Therefore, there is a demand for a cleaning liquid that can sufficiently remove the photoresist and the antireflection film without performing a dry ashing process or the like.

  Conventionally, as a semiconductor device cleaning liquid for removing the above-described photoresist, antireflection film, etching residue, ashing residue, etc., for example, a cleaning liquid composed of a mixed system of alkanolamine and an organic solvent has been proposed (Patent Document 1). And 2). Patent Document 3 discloses a cleaning liquid composed of alkanolamine, hydroxylamine, catechol and water.

  Patent Document 4 discloses a cleaning liquid comprising an alcohol solvent, a halogen solvent, and an organic quaternary ammonium salt.

  Patent Document 5 discloses a cleaning liquid comprising water, tetramethylammonium hydroxide, hydrogen peroxide, and a nonionic surfactant.

  Patent Document 6 discloses a cleaning liquid comprising sodium hydroxide or potassium hydroxide, a water-soluble organic solvent, and a group 9 or group 11 metal corrosion inhibitor.

JP 62-49355 A JP-A 64-42653 JP-A-4-289866 US Pat. No. 5,185,235 JP 7-297158 A JP 2007-1119783 A

However, when the present inventors have studied the above-mentioned cleaning liquid, they have found the following problems.
(1) In the cleaning liquids described in Patent Documents 1 to 3, the removability of the antireflection film, for example, the organosiloxane antireflection film, was not sufficient.
(2) In the cleaning liquid described in Patent Document 4, the removability of the photoresist and the antireflection film (for example, organosiloxane antireflection film) is not sufficient.
(3) The cleaning liquid described in Patent Document 5 requires high temperature to remove the photoresist and antireflection film (for example, organosiloxane antireflection film), and requires a long time. It was not enough for device manufacture aiming for.
(4) With the cleaning solution described in Patent Document 6, cleaning performance can be obtained in a relatively short time, but the use temperature is not sufficiently low, and the time required is not short. In addition, benzotriazoles used as corrosion inhibitors have a high environmental load, such as low biodegradability, and there is a problem that a large amount of cost is required for environmental equipment such as waste liquid treatment.

  Conventional cleaning solutions have not been able to remove photoresist, etching residues, antireflection films, ashing residues, or the like. In addition, even if it can be removed, the cleaning process takes a long time, the low-k material contained in the semiconductor device is etched, or the use of a heterocyclic-containing metal corrosion inhibitor has a high environmental impact. Had problems.

  Therefore, in the present invention, removal of deposits on the surface of the object to be cleaned, such as photoresist, etching residue, antireflection film, and ashing residue, is low in environmental load and does not corrode the interlayer insulating film. It is an object of the present invention to provide a cleaning liquid for a semiconductor device that can be performed, and a cleaning method for a semiconductor device using the cleaning liquid.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by the following <1> to <13> configurations.

<1> A cleaning liquid for semiconductor devices, which contains an oxidizing agent, a metal etching agent, and a surfactant and has a pH of 10 to 14.
<2> The semiconductor device cleaning liquid according to <1>, wherein the oxidizing agent is hydrogen peroxide.
<3> The semiconductor device cleaning solution according to <1>, wherein the metal etchant is an amine compound.
<4> The semiconductor device cleaning solution according to <3>, wherein the amine compound is at least one selected from the group consisting of ethylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and derivatives thereof. .
<5> The semiconductor device cleaning liquid according to any one of <1> to <4>, further comprising an inorganic alkali compound or a quaternary ammonium hydroxide represented by the following general formula (1).

（一般式（１）中、Ｒ_１〜Ｒ_４はそれぞれ独立に炭素数１〜６のアルキル基、炭素数１〜６のヒドロキシアルキル基、ベンジル基、またはアリール基を表す。）
＜６＞ 前記無機アルカリ化合物が、水酸化リチウム、水酸化ナトリウム、水酸化カリウム、水酸化ルビジウム、および、水酸化セシウムからなる群から選ばれる少なくとも１種である＜５＞に記載の半導体デバイス用洗浄液。
＜７＞ 前記界面活性剤が、カチオン性界面活性剤またはノニオン性界面活性剤である＜１＞〜＜６＞のいずれかに記載の半導体デバイス用洗浄液。
＜８＞ 前記カチオン性界面活性剤が、第４級アンモニウム塩系界面活性剤、およびアルキルピリジウム系界面活性剤からなる群から選ばれる少なくとも１種である＜７＞に記載の半導体デバイス用洗浄液。
＜９＞ 前記ノニオン性界面活性剤が、ポリプロピレンオキサイドポリエチレンオキサイド系界面活性剤、ポリアルキレンオキサイドジスチレン化フェニルエーテル系界面活性剤、ポリアルキレンオキサイドアルキルフェニルエーテル系界面活性剤、ポリアルキレンオキサイドトリベンジルフェニルエーテル系界面活性剤、アセチレンポリアルキレンオキサイド系界面活性剤、および、ポリアルキレンオキサイドアルキルエーテル系界面活性剤からなる群から選ばれる少なくとも1種である＜７＞に記載の半導体デバイス用洗浄液。
＜１０＞ ＜１＞〜＜９＞のいずれかに記載の半導体デバイス用洗浄液を用いて、半導体デバイスを洗浄する半導体デバイスの洗浄方法。
＜１１＞ ドライエッチング工程の後に、＜１＞〜＜９＞のいずれかに記載の半導体デバイス用洗浄液を用いて半導体デバイスを洗浄する洗浄工程を実施することを特徴とする半導体デバイスの洗浄方法。
＜１２＞ 前記半導体デバイスが、誘電率ｋが３．０以下である層間絶縁膜を含有する半導体デバイスである＜１０＞または＜１１＞に記載の半導体デバイスの洗浄方法。

(In the general formula (1), R _{1 to} R ₄ each independently represents an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a benzyl group, or an aryl group.)
<6> The semiconductor device according to <5>, wherein the inorganic alkali compound is at least one selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Cleaning liquid.
<7> The semiconductor device cleaning solution according to any one of <1> to <6>, wherein the surfactant is a cationic surfactant or a nonionic surfactant.
<8> The cleaning liquid for a semiconductor device according to <7>, wherein the cationic surfactant is at least one selected from the group consisting of a quaternary ammonium salt surfactant and an alkylpyridium surfactant. .
<9> The nonionic surfactant is a polypropylene oxide polyethylene oxide surfactant, polyalkylene oxide distyrenated phenyl ether surfactant, polyalkylene oxide alkylphenyl ether surfactant, polyalkylene oxide tribenzylphenyl The semiconductor device cleaning solution according to <7>, which is at least one selected from the group consisting of an ether surfactant, an acetylene polyalkylene oxide surfactant, and a polyalkylene oxide alkyl ether surfactant.
<10> A semiconductor device cleaning method for cleaning a semiconductor device using the semiconductor device cleaning liquid according to any one of <1> to <9>.
<11> A method for cleaning a semiconductor device, comprising performing a cleaning step for cleaning the semiconductor device using the semiconductor device cleaning liquid according to any one of <1> to <9> after the dry etching step.
<12> The semiconductor device cleaning method according to <10> or <11>, wherein the semiconductor device is a semiconductor device including an interlayer insulating film having a dielectric constant k of 3.0 or less.

  According to the present invention, removal of deposits on the surface of an object to be cleaned, such as a photoresist, an etching residue, an antireflection film, and an ashing residue, has a low environmental load and does not corrode an interlayer insulating film material. It can be performed. Further, the semiconductor device cleaning liquid of the present invention (hereinafter also simply referred to as “cleaning liquid”) can remove deposits without containing a heterocyclic metal corrosion inhibitor.

  In the present invention, the etching residue refers to a by-product generated by etching, and refers to an organic residue, a Si-containing residue, and a metal-containing residue derived from a photoresist. In the present invention, the ashing residue refers to a by-product generated by ashing, and refers to a photoresist-derived organic residue, a Si-containing residue, and a metal-containing residue.

  The cleaning liquid according to the present invention is a cleaning liquid used in the manufacture of semiconductor devices, and includes an oxidizing agent, a metal etching agent, and a surfactant, and has a pH of 10 to 14. Below, each specific aspect is demonstrated.

<Oxidizing agent>
The cleaning liquid of the present invention contains an oxidizing agent. Here, the oxidizing agent may be a compound having an oxidizing action. Among these, hydrogen peroxide, ammonium persulfate, chloric acid, chlorous acid, hypochlorous acid, perchloric acid, permanganic acid are more excellent in terms of both the ability to remove residues and the corrosiveness to insulating films. At least one compound selected from the group consisting of iodic acid, hypoiodic acid, periodic acid, and orthoperiodic acid is preferred. In the present invention, hydrogen peroxide or orthoperiodic acid is particularly preferable. The oxidizing agents may be used alone or in combination of two or more.

  The content of the oxidizing agent with respect to the total mass of the cleaning liquid is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass. It is preferable for the content of the oxidizing agent to be within the above-mentioned numerical value range because etching of the metal material contained in the semiconductor device is appropriate.

<Metal etchant>
The cleaning liquid of the present invention contains a metal etchant. A metal etchant refers to a compound that can be etched into a metal, a metal nitride, or an alloy by being added to the cleaning composition. Specific examples include amine compounds, inorganic acids, organic acids, sulfonic acid compounds, heterocycle-containing compounds, sulfonic acid compounds, and the like. From the point that copper can be selectively etched, amine compounds are used in the present invention. The use of compounds is preferred.

  Examples of the amine compound include ammonia, amine compounds containing a plurality of N atoms such as ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, and alkylamines such as methylamine and ethylamine (the number of carbon atoms in the alkyl chain is 1). To 16 and more preferably 1 to 8), dialkylamines such as dimethylamine and diethylamine (preferably 1 to 16 carbon atoms of each alkyl chain, more preferably 1 to 8), trialkylamines such as trimethylamine and triethylamine (C1-C16 of an alkyl chain is preferable, and 1-8 are more preferable), Alkanolamine compounds, such as monoethanolamine and diethanolamine, are mentioned. Of these, ethylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine are preferable, and ethylenediamine and diethylenetriamine are particularly preferable because copper can be selectively etched.

  The content of the metal etching agent with respect to the total mass of the cleaning liquid is preferably 0.00001 to 10% by mass, and preferably 0.00001 to 5% by mass with respect to the total mass of the cleaning liquid. It is preferable for the content of the metal etchant to be within the above numerical value range because the etching of the metal contained in the semiconductor device can be adjusted appropriately.

<Surfactant>
The cleaning liquid of the present invention contains a surfactant. As the surfactant, nonionic, anionic, cationic surfactants, and amphoteric surfactants can be used.

As the surfactant used in the present invention, the viscosity of the cleaning liquid can be adjusted by adding it, and the wettability to the object to be cleaned can be improved. Nonionic surfactants can be preferably used from the viewpoint that both of the corrosiveness to the above are superior. Nonionic surfactants include, for example, polyalkylene oxide alkylphenyl ether surfactants, polyalkylene oxide alkyl ether surfactants, block polymer surfactants composed of polyethylene oxide and polypropylene oxide, and polyoxyalkylene distyrenation. Phenyl ether surfactants, polyalkylene tribenzyl phenyl ether surfactants, acetylene polyalkylene oxide surfactants, and the like can be used.
Among them, a polyalkylene oxide (hereinafter referred to as PAO) alkyl ether surfactant is preferably a PAO decyl ether, PAO lauryl ether, PAO tridecyl ether, PAO alkylene decyl ether, PAO sorbitan monolaurate, PAO sorbitan monooleate, It is a polyalkylene oxide alkyl ether surfactant selected from PAO sorbitan monostearate, polyethylene oxide sorbite tetraoleate, PAO alkylamine, and PAO acetylene glycol. As the polyalkylene oxide, a polymer of polyethylene oxide, polypropylene oxide or polybutylene oxide is preferable. Other suitable examples include polypropylene oxide, polyethylene oxide surfactants, polyalkylene oxide distyrenated phenyl ether surfactants, polyalkylene oxide alkylphenyl ether surfactants, polyalkylene oxide tribenzylphenyl ether surfactants Agents, acetylene polyalkylene oxide surfactants, polyalkylene oxide alkyl ether surfactants, and the like.

  Moreover, as a surfactant used in the present invention, the viscosity of the cleaning liquid can be adjusted by adding it, and the wettability to the object to be cleaned can be improved. Cationic surfactants can also be preferably used from the viewpoint that both corrosiveness to a film and the like are more excellent. The cationic surfactant is preferably a quaternary ammonium salt surfactant or an alkyl pyridium surfactant.

  As the quaternary ammonium salt surfactant, a compound represented by the following general formula (2) is preferable.

（一般式（２）中、Ｘ⁻は水酸化物イオン、塩素イオン、臭素イオン、または硝酸イオンを表す。Ｒ_５は炭素数８〜１８のアルキル基を表す。Ｒ_６およびＲ_７は、それぞれ独立に炭素数８〜１８のアルキル基、アリール基、炭素数１〜８のヒドロキシアルキル基、またはベンジル基を表す。Ｒ_８は炭素数１〜３のアルキル基を表す。）

(In the general formula (2), X ^- .R ₆ and _{R 7} .R ₅ represents an alkyl group having 8 to 18 carbon atoms representing the hydroxide ion, chloride ion, bromine ion or nitrate ion, respectively Independently represents an alkyl group having 8 to 18 carbon atoms, an aryl group, a hydroxyalkyl group having 1 to 8 carbon atoms, or a benzyl group, and R ₈ represents an alkyl group having 1 to 3 carbon atoms.

In the general formula (2), X ⁻ represents a counter anion, specifically a hydroxide ion, a chlorine ion, a bromine ion, or a nitrate ion.

In General Formula (2), R ₅ represents an alkyl group having 8 to 18 carbon atoms (preferably having 12 to 18 carbon atoms, such as a cetyl group or a stearyl group).

R ₆ and R ₇ each independently represents an alkyl group having 1 to 18 carbon atoms, a hydroxyalkyl group having 1 to 8 carbon atoms (for example, hydroxyethyl), an aryl group (for example, phenyl group), or a benzyl group. To express.

In the general formula (2), R ₈ represents an alkyl group having 1 to 3 carbon atoms (for example, a methyl group, an ethyl group, etc.).

  Specific examples of the compound represented by the general formula (2) include cetyltrimethylammonium chloride, didodecyldimethylammonium chloride, tridecylmethylammonium chloride, stearylbenzyldimethylammonium chloride and the like. The counter anion of these compounds is not limited to chlorine ions, but may be bromine ions or hydroxide ions.

  Specific examples of the alkyl pyridium surfactant include cetyl pyridinium chloride. The counter anion of these compounds is not limited to chlorine ions, but may be bromine ions or hydroxide ions.

  The content of the surfactant in the cleaning liquid is preferably 0.0001 to 5% by mass and more preferably 0.0001 to 1% by mass with respect to the total amount of the cleaning liquid. It is preferable because the viscosity of the cleaning liquid can be adjusted by adding a surfactant to the cleaning liquid, and the wettability to the object to be cleaned can be improved. In addition, the corrosiveness to the substrate and the insulating film is more excellent. preferable. Such surfactants are generally commercially available. These surfactants may be used alone or in combination.

<PH>
The pH of the cleaning liquid of the present invention is 10-14, more preferably 11-14. It is preferable for the pH to be within the above numerical value range since the photoresist, antireflection film, etching residue, and ashing residue can be sufficiently removed. As a measuring method of pH, it can measure using a well-known pH meter.

  The cleaning liquid of the present invention preferably contains an alkaline compound to achieve the above pH. An alkaline compound is a compound in which an aqueous solution exhibits alkalinity by containing it in an aqueous solution. Specifically, an inorganic alkali compound such as an alkali metal hydroxide composed of a pair of an alkali metal element and a hydroxyl group, or a quaternary ammonium hydroxide represented by the general formula (1) can be given.

  Among the inorganic alkali compounds, alkali metal hydroxides are preferable, and specifically, at least one alkali selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. A metal hydroxide is preferred. Of these, sodium hydroxide and potassium hydroxide are more preferable from the viewpoint of ease of handling. The alkali metal hydroxide compounds or hydrates thereof may be used alone or in combination of two or more.

（一般式（１）中、Ｒ_１〜Ｒ_４は、それぞれ独立に炭素数１〜６のアルキル基、炭素数１〜６のヒドロキシアルキル基、ベンジル基、またはアリール基を表す。） Here, the quaternary ammonium hydroxide is a compound represented by the following general formula (1).

(In the general formula (1), R _{1 to} R ₄ each independently represents an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a benzyl group, or an aryl group.)

In General Formula (1), R _{1 to} R ₄ are each independently an alkyl group having 1 to 6 carbon atoms (for example, a methyl group, an ethyl group, a butyl group, etc.), or a hydroxyalkyl group having 1 to 6 carbon atoms (for example, , A hydroxymethyl group, a hydroxyethyl group, a hydroxybutyl group, etc.), a benzyl group, or an aryl group (for example, a phenyl group, a naphthyl group, etc.). Of these, an alkyl group, a hydroxyethyl group, and a benzyl group are preferable.

Specifically, from tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, methyltri (hydroxyethyl) ammonium hydroxide, tetra (hydroxyethyl) ammonium hydroxide, trimethylbenzylammonium hydroxide, and choline Preferably, it is at least one quaternary ammonium hydroxide selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, benzyltrimethylammonium hydroxide, or choline. It is more preferable. Quaternary ammonium hydroxides may be used alone or in combination of two or more.
The alkali metal hydroxide or quaternary ammonium hydroxide may be used in combination of two or more.

  The content of the alkaline compound (inorganic alkaline compound, quaternary ammonium hydroxide represented by the general formula (1), etc.) with respect to the total mass of the cleaning liquid of the present invention is preferably 0.01 to 20% by mass, more preferably. Is 0.1 to 10% by mass, more preferably 0.1 to 5% by mass. When the content of the alkaline compound is within the above numerical range, the photoresist, the antireflection film, the etching residue, and the ashing residue can be sufficiently removed, and in addition, an interlayer insulating film mainly composed of SiOC or It is preferable because corrosion of the silicon substrate can be further suppressed or reduced.

<Others>
The cleaning liquid of the present invention is an aqueous solution, and the water content is 50 to 98% by mass with respect to the total mass of the cleaning liquid. Further, it is preferable that the cleaning liquid of the present invention does not use a heterocyclic-containing metal corrosion inhibitor such as benzotriazole as much as possible, and more preferably does not substantially contain it.

  The cleaning liquid of the present invention may contain a water-soluble organic solvent, a fluorine-containing compound, and a chelating agent as necessary. By containing these, more preferable performance can be obtained.

<Water-soluble organic solvent>
The cleaning liquid of the present invention may contain a water-soluble organic solvent. Examples of the water-soluble organic solvent include alcohol solvents such as methyl alcohol, ethyl alcohol, 1-propyl alcohol, 2-propyl alcohol, ethylene glycol, propylene glycol, glycerin, 1,6-hexanediol, sorbitol, and xylitol, ethylene glycol Ether solvents such as monomethyl ether, diethylene glycol, diethylene glycol monomethyl ether, triethylene glycol, polyethylene glycol, propylene glycol monomethyl ether, formamide, monomethylformamide, dimethylformamide, acetamide, monomethylacetamide, dimethylacetamide, monoethylacetamide, diethylacetamide, N -Amide solvents such as methylpyrrolidone, dimethyl sulfone, Methyl sulfoxide, sulfur-containing solvents such as sulfolane, .gamma.-butyrolactone, lactone-based solvents such as δ- valerolactone. Among these, alcohol-based, ether-based, amide-based, and sulfur-containing solvents are preferable, and 1,6-hexanediol, tetraethylene glycol, propylene glycol, dipropylene glycol monomethyl ether, and N-methylpyrrolidone are more preferable. And dimethyl sulfoxide. The water-soluble organic solvents may be used alone or in combination of two or more.

  The content of the water-soluble organic solvent in the cleaning liquid is preferably used at a concentration of 0 to 40% by mass, more preferably 0 to 20% by mass with respect to the total weight of the cleaning liquid. It is preferable to add a water-soluble organic solvent to the cleaning liquid because removal of etching residues can be promoted.

<Fluorine-containing compound>
The cleaning liquid of the present invention may contain a fluorine-containing compound. The fluorine-containing compound is a fluoride salt formed by reacting hydrofluoric acid with ammonia or an organic amine. For example, ammonium fluoride, acidic ammonium fluoride, methylamine hydrogen fluoride salt, ethylamine fluoride salt, propylamine fluoride salt, tetramethylammonium fluoride, tetraethylammonium fluoride, ethanolamine hydrogen fluoride salt, triethylenediamine fluoride Examples thereof include hydrides. These may be used alone or in combination of two or more.

  The content of the fluorine-containing compound in the cleaning liquid is preferably used at a concentration of 0 to 10% by mass with respect to the total weight of the cleaning liquid. It is preferable to add a fluorine-containing compound in addition to the cleaning liquid because removal of the photoresist, the antireflection film, the etching residue, and the ashing residue can be promoted.

<Chelating agent>
The cleaning liquid of the present invention may contain a chelating agent. As the chelating agent, aminopolycarboxylate group consisting of {ethylenediaminetetraacetate (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylethylenediaminetriacetate (HEDTA), dihydroxyethylethylenediaminetetraacetate (DHEDDA), Nitriro acid acetate (NTA), hydroxyethyliminodiacetate (HIDA), β-alanine diacetate, aspartate diacetate, methylglycine diacetate, iminodisuccinate, serine diacetate, hydroxyiminodisuccinate , Dihydroxyethylglycine salt, aspartate, glutamate, etc.}, hydroxycarboxylate group consisting of {hydroxyacetate, tartrate, citrate, gluconate, etc.}, cyclocarboxylate group consisting of { Lomellitic acid salt, benzopolycarboxylic acid salt, cyclopentanetetracarboxylic acid salt, etc.}, ether carboxylate group consisting of {carboxymethyl tarturonate, carboxymethyloxysuccinate, oxydisuccinate, tartaric acid monosuccinate, Tartrate disuccinate, etc.}, other carboxylate group consisting of {maleic acid derivative, oxalate, etc.}, organic carboxylic acid (salt) polymer group consisting of {acrylic acid polymer and copolymer (acrylic acid-allyl alcohol) Copolymer, acrylic acid-maleic acid copolymer, hydroxyacrylic acid polymer, polysaccharide-acrylic acid copolymer, etc.), polyvalent carboxylic acid polymer and copolymer group {maleic acid, itaconic acid , Fumaric acid, tetramethylene-1,2-dicarboxylic acid, succinic acid , Polymers and copolymers of monomers such as aspartic acid and glutamic acid}, glyoxylic acid polymer consisting of the following: polysaccharide group {starch, cellulose, amylose, pectin, carboxymethyl cellulose, etc.}, phosphonate group consisting of { Methyl diphosphonate, aminotrismethylene phosphonate, ethylidene diphosphonate, 1-hydroxyethylidene-1,1-diphosphonate, ethylaminobismethylene phosphonate, ethylenediamine bismethylene phosphonate, ethylenediamine tetramethylene Phosphonate, hexamethylenediaminetetramethylenephosphonic acid, propylenediaminetetramethylenephosphonate, diethylenetriaminepentamethylenephosphonate, triethylenetetraminehexamethylenephosphonate And tetraethylene pentamine heptamethylene phosphonates such} and the like. Examples of these salts include ammonium salts and alkanolamine (monoethanolamine, triethanolamine, etc.) salts. These may be used alone or in combination of two or more.

  The content of the chelating agent in the cleaning liquid is preferably used at a concentration of 0 to 10% by mass with respect to the total mass of the cleaning liquid. It is preferable to add a chelating agent in addition to the cleaning liquid because removal of the metal-containing residue can be promoted.

<Object to be cleaned>
In the present invention, the material of the semiconductor device to be cleaned is silicon, amorphous silicon, polysilicon, silicon oxide, silicon nitride, copper, titanium, titanium-tungsten, titanium nitride, tungsten, chromium, chromium oxide. Semiconductor substrate materials such as aluminum, semiconductor substrates coated with compound semiconductors such as gallium-arsenic, gallium-phosphorus, and indium-phosphorus, printed substrates such as polyimide resins, glass substrates used for LCDs, etc. . In the cleaning liquid of the present invention, the etching of the metal-containing material can be controlled, but other materials such as wiring materials represented by silicon oxide are not corroded.

  Moreover, the cleaning liquid of the present invention can be suitably used for a semiconductor device (for example, a semiconductor device substrate) having an interlayer insulating film. The interlayer insulating film preferably has a dielectric constant k of 3.0 or less, more preferably 2.6 or less. Specific examples of the interlayer insulating film material include SiOC-based materials and organic polymers such as polyimide. Can be mentioned. A specific example of a semiconductor device (semiconductor element) in which the cleaning liquid of the present invention is used includes, for example, a substrate for a semiconductor device such as an integrated circuit (IC, LSI). Semiconductor device substrates include, for example, a single-layer substrate with metal wiring formed on the surface of a base material, a multilayer wiring substrate with wiring formed on the surface via an interlayer insulating film, and a photoresist layered. And multilayer wiring boards. The cleaning liquid of the present invention does not corrode these materials (wiring material, interlayer insulating film material, etc.) and can remove residues.

<Washing method>
In the cleaning method of the present invention, after preparing the cleaning liquid of the present invention (cleaning liquid preparation step), the semiconductor device is cleaned using the obtained cleaning liquid to remove the photoresist, the antireflection film, the etching residue, and the ashing residue. A cleaning step is provided.

  The method for preparing the cleaning liquid of the present invention is not particularly limited. For example, a reducing agent, a surfactant, an inorganic alkali compound that can be used as necessary, a quaternary ammonium hydroxide, and the like can be produced by sufficiently mixing them using a stirrer such as a mixing mixer. it can. Moreover, the method of mixing after adjusting to preset pH beforehand, or the method of adjusting to preset pH after mixing can also be used.

  The washing step can be performed by any known method. Examples of the method for bringing the cleaning liquid into contact with the photoresist to be cleaned include a dipping method, a spraying method, a method using a single wafer method, and the like. More specifically, a dip type in which a cleaning tank is filled with a cleaning liquid and a semiconductor device (for example, a semiconductor integrated circuit substrate) is immersed, a spray type in which the cleaning liquid is sprayed and cleaned, and a cleaning liquid is allowed to flow from the nozzle onto the substrate. However, there is a spin type that rotates the substrate at a high speed.

  The temperature of the cleaning liquid in carrying out the cleaning method of the present invention can be appropriately selected depending on the method used, etching conditions and the cleaning target used, but is preferably in the range of 15 to 100 ° C. The range of 80 ° C is more preferable, and the range of 20 to 55 ° C is more preferable. If it is within the above range, both the removability of residue and the corrosiveness to the substrate and insulating film are better, the cleaning effect is better, and it can be carried out in a low temperature process, so no special equipment is required preferable.

  The time for bringing the cleaning liquid of the present invention into contact with the semiconductor device having a photoresist or the like is preferably 30 seconds to 30 minutes, more preferably 30 seconds to 10 minutes, and further preferably 30 seconds to 5 minutes. Within the above numerical range, the photoresist, the antireflection film, the etching residue, and the ashing residue can be sufficiently removed, and the time required for the cleaning method is short, which is preferable.

  In the cleaning method of the present invention, it is also preferable to remove the photoresist and the like by repeating the cleaning step with the cleaning liquid twice or more. Repeating the washing step twice or more is preferable because the removal performance of the photoresist and the like is improved. The washing step can be repeated any number of times until the photoresist and the like are completely removed, but is preferably repeated 1 to 3 times, more preferably 1 to 2 times.

  The washing | cleaning method of this invention can use an ultrasonic wave together as needed in the said washing | cleaning process.

  After removing the photoresist and the like on the object to be cleaned, the semiconductor device may be cleaned (rinsed) if necessary. As the rinse, water, warm water of about 50 ° C., or isopropanol is preferable.

  As a cleaning process using the cleaning liquid of the present invention, for example, in the case of a substrate for a semiconductor device having a metal wiring such as copper or an interlayer insulating film on the surface, after performing CMP (Chemical Mechanical Polishing) on the copper film Cleaning process, a cleaning process after opening a hole in the interlayer insulating film on the wiring by dry etching, a cleaning process after performing a dry ashing process on the photoresist, and the like.

  As a preferred embodiment of the cleaning method of the present invention, the above-described cleaning treatment (cleaning step) is performed after the dry etching step of the semiconductor device. More specifically, after performing a dry etching process on a desired semiconductor device, the semiconductor device is cleaned using the above-described cleaning liquid in order to remove etching residues and photoresist. In a general photolithography technique, a wet etching process using a specific photoresist stripping solution or a dry ashing process is performed to remove the photoresist after the dry etching process. On the other hand, if the cleaning liquid of the present invention is used, the photoresist and the etching residue can be removed by performing the cleaning process after the dry etching process without passing through the above-described processing process. Thereby, by not passing through the dry ashing process, damage to the interlayer insulating film material (particularly, the low-k material) can be kept small, and further, the processing process can be simplified and the manufacturing time of the semiconductor device can be shortened. At the same time, manufacturing costs can be reduced.

  The cleaning liquid according to the present invention can selectively etch the metal, the metal nitride, and the alloy contained in the cleaning object at the same time as removing the etching residue and the ashing residue. In detail, the etching rate with respect to metals, such as copper and TiN, a metal nitride, and an alloy can be arbitrarily adjusted by selecting the component of a washing | cleaning liquid suitably. Generally, in semiconductor device manufacturing processes, various solutions such as various cleaning solutions and etching solutions used for wet etching are used, and it is necessary to switch the solution used for each process or production line. Caused a decline in sex and cost. When the cleaning liquid according to the present invention is used, etching of a desired metal can be performed simultaneously with cleaning. Therefore, the process can be simplified, the production cost is reduced, the mass productivity is improved, and the amount of the solution used in the manufacturing process is reduced, which leads to improvement of problems relating to waste liquid treatment.

  The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

<Example A>
On the silicon substrate, copper, SiOC-based interlayer insulating film (Low-k film: k value 2.6), SiO ₂ film (TEOS film), metal hard mask (TiN), antireflection film, and photoresist are sequentially formed. Using the exposed and developed photoresist as a mask, dry etching is performed to form a via hole, and a patterned wafer in which copper, an interlayer insulating film, a metal hard mask, an antireflection film, and a photoresist are exposed on the inner wall surface of the via hole is obtained. It was.
When the cross section of the pattern wafer was confirmed by a scanning electron micrograph (SEM), etching residues were found on the via hole wall surface.

<Examples 1-9 and Comparative Examples 1-3>
Subsequently, cleaning solutions 1 to 12 having the compositions shown in Table 1 were prepared (Emulgen, which is given as an example of a surfactant, is sold by Kao Corporation, and Surfynol is sold by Nissin Chemical Industry Co., Ltd. It is a nonionic surfactant.) In each solution adjusted to the temperature described in Table 1, the section of the pattern wafer (2 cm × 2 cm) is immersed, and after the immersion time described in Table 1, the section of the pattern wafer is taken out and immediately washed with ultrapure water. N ₂ drying was performed. The cross section and surface of the sections of the pattern wafer after the immersion test was observed by SEM, photoresist, removal of the etching residue, and, below the silicon substrate, SiO ₂ film, the corrosion resistance of the SiOC-based interlayer insulating film The evaluation was performed according to the criteria. An immersion test was conducted at an immersion temperature of 20 to 55 ° C. and an immersion time of 30 seconds to 20 minutes, and the evaluation results of removability and corrosivity are summarized in Table 1.

The evaluation criteria are shown below.
<Removability>
A: The photoresist, the antireflection film and the etching residue were completely removed.
B: Photoresist, antireflection film, and poorly dissolved etching residue remained.
C: The photoresist, the antireflection film and the etching residue were hardly removed.

《Corrosive》
A: No corrosion was observed on the silicon substrate, the SiO ₂ film, or the SiOC interlayer insulating film.
B: Some corrosion was observed on at least one of the silicon substrate, the SiO ₂ film, and the SiOC interlayer insulating film.
C: Significant corrosion was observed on at least one of the silicon substrate, the SiO ₂ film, and the SiOC-based interlayer insulating film.

  In the above evaluation, it is desirable that all are A in removability and corrosivity.

As shown in Table 1, in Examples 1 to 9 to which the cleaning liquid and the cleaning method of the present invention are applied, there is no corrosion of the silicon substrate and the SiOC-based interlayer insulating film, and the photoresist, the antireflection film and the etching residue can be removed. It was excellent. In cleaning using the cleaning liquid of the present invention, the immersion temperature and immersion time can be selected relatively freely, and cleaning at a low temperature and in a short time is possible. The corrosion of the SiO ₂ film and the SiOC-based interlayer insulating film did not progress. In Comparative Examples 1 to 3, even if the immersion time and immersion temperature are adjusted, sufficient removal of photoresist, antireflection film and etching residue, non-corrosiveness of silicon substrate, SiO ₂ film, and SiOC-based interlayer insulating film There was nothing to show.

<Example B>
A piece of blanket wafer in which a TiN film (thickness of about 60 nm) and a Cu film (thickness of about 200 nm) are separately formed is immersed in cleaning solutions 1 to 8 prepared in the same manner as in Example A above, and the films before and after the immersion The etching rate (Å / min) for each film was calculated by measuring from the thickness measurement and immersion time. The results are shown in Table 2.
The film thickness was measured using a film thickness measuring apparatus (F20) manufactured by Filmetrics Co., Ltd.

  As shown in Table 2, it was found that in Examples 10 to 17 to which the cleaning liquid and the cleaning method of the present invention were applied, the etching rates of Cu and TiN could be freely adjusted. Furthermore, by adjusting the amount of the oxidizing agent, the amount of the metal etching agent, and the processing temperature, it was possible to obtain a desired etching rate in a more controlled manner.

  As described above, from Examples A and B, the photoresist contained in the object to be cleaned without eroding the interlayer insulating film contained in the object to be cleaned in the cleaning process with the cleaning liquids 1 to 8 according to the present invention. It has been found that an antireflection film and etching residues can be removed, and at the same time, a cleaning liquid capable of selectively etching a metal, a metal nitride, and an alloy contained in an object to be cleaned and a cleaning method therefor can be provided.

Claims (12)

  A cleaning solution for a semiconductor device, which contains an oxidizing agent, a metal etching agent, and a surfactant and has a pH of 10 to 14.   The cleaning liquid for a semiconductor device according to claim 1, wherein the oxidizing agent is hydrogen peroxide.   The cleaning liquid for a semiconductor device according to claim 1, wherein the metal etching agent is an amine compound.   The cleaning liquid for semiconductor devices according to claim 3, wherein the amine compound is at least one selected from the group consisting of ethylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and derivatives thereof. Furthermore, the washing | cleaning liquid for semiconductor devices in any one of Claims 1-4 containing the quaternary ammonium hydroxide represented by an inorganic alkali compound or General formula (1).

(In the general formula (1), R _{1 to} R ₄ each independently represents an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a benzyl group, or an aryl group.)   The cleaning liquid for a semiconductor device according to claim 5, wherein the inorganic alkali compound is at least one selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide.   The semiconductor device cleaning liquid according to claim 1, wherein the surfactant is a cationic surfactant or a nonionic surfactant.   The cleaning liquid for a semiconductor device according to claim 7, wherein the cationic surfactant is at least one selected from the group consisting of a quaternary ammonium salt surfactant and an alkyl pyridium surfactant.   The nonionic surfactant is a polypropylene oxide polyethylene oxide surfactant, a polyalkylene oxide distyrenated phenyl ether surfactant, a polyalkylene oxide alkylphenyl ether surfactant, a polyalkylene oxide tribenzylphenyl ether interface. The semiconductor device cleaning liquid according to claim 7, which is at least one selected from the group consisting of an activator, an acetylene polyalkylene oxide surfactant, and a polyalkylene oxide alkyl ether surfactant.   A semiconductor device cleaning method for cleaning a semiconductor device using the semiconductor device cleaning liquid according to claim 1.   A method for cleaning a semiconductor device, comprising a step of cleaning the semiconductor device using the semiconductor device cleaning liquid according to claim 1 after the dry etching step.   The method for cleaning a semiconductor device according to claim 10 or 11, wherein the semiconductor device is a semiconductor device containing an interlayer insulating film having a dielectric constant k of 3.0 or less.