JP2012046685A - Cleaning composition, cleaning method using the composition, and method of manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a cleaning composition that solves a problem peculiar to a cleaning composition containing a specific cleaning agent substantially neutralized, prevents a metal layer of a semiconductor substrate, especially titanium nitride from being eroded, and removes plasma-etching residues and ashing residues caused during the manufacturing process; a cleaning method using the composition; and a method of manufacturing a semiconductor device.SOLUTION: The cleaning composition for semiconductor substrate contains: water; the cleaning agent; a basic organic compound; an acid organic compound; and a specific nitrogen-containing aromatic ring compound. The cleaning composition is substantially neutralized.

Description

  The present invention relates to a cleaning composition, a cleaning method using the same, and a method for manufacturing a semiconductor element.

  In the manufacture of integrated circuits, positive photoresist is used as an intermediate mask. Specifically, it is used as a medium for transferring a mask pattern of a focusing screen onto a semiconductor substrate (wafer substrate) in a processing process combining a series of photographic flat plates and plasma etching. The patterned photoresist film is removed from the substrate at a predetermined stage in the integrated circuit manufacturing process. Generally, the removal of this photoresist film is performed by the following two methods.

  The first method includes a “wet stripping step” in which a photoresist-coated substrate is first brought into contact with a photoresist stripper solution composed of an organic solvent and an amine. However, in the method using the stripper solution, when the photoresist film is exposed to ultraviolet irradiation or plasma treatment during production, it may not be completely removed. As a factor, it may be mentioned that the photoresist film is altered by the ultraviolet irradiation treatment as described above and is not easily dissolved in the stripper solution. Further, in many cases, the solvent used in such a wet stripping method has a low effect of removing inorganic residue substances formed during plasma etching using a halogen-containing gas.

  The second method includes plasma ashing. In this method, first, a photoresist-coated wafer is exposed to an oxygen-based plasma in order to burn the resist film from the surface of the semiconductor substrate. Since this process is performed in a vacuum chamber, it is not easily affected by the contamination of airborne fine particles and metals. Based on such advantages, the plasma ashing is widely used in the manufacturing process of integrated circuits.

  However, plasma ashing is not completely effective in removing the above-mentioned plasma etching by-product. Therefore, the plasma etching by-product (residue) needs to be separately removed by cleaning with a cleaning solution or the like by either plasma ashing or the above-described wet stripping. In plasma ashing, it is necessary to clean and remove by-products (residues) generated thereby.

  Several commercial products are currently available for removing plasma etching by-products (residues) left by plasma etching after plasma ashing (eg, EKC 265 (trade name) manufactured by EKC Technology Inc., Ashland Chemical) ACT 935 (trade name) manufactured by Mitsubishi Gas Chemical Co., Ltd. ELM C-30 (trade name)). These products are also disclosed as patent documents (see Patent Documents 1 to 3). However, these commercial products have a high pH of 11 or more and contain fluorine compounds, and can effectively decompose the plasma etching residue, but also attack the deposition pattern of metals and oxides on the substrate. May end up. In these products, a corrosion inhibitor is applied, but it is difficult to obtain sufficient corrosion resistance by itself.

  On the other hand, a cleaning composition that does not adversely affect the semiconductor substrate has been developed (see Patent Document 4). This is a water-based composition (cleaning solution), which contains an acid such as a hydroxylamine compound, a basic compound, or an organic acid, thereby preventing corrosion while maintaining cleaning properties. Further, this cleaning liquid is water-based with water as a main medium, and has the advantages of being low in cost and excellent in environmental compatibility with respect to organic cleaning liquid.

US Pat. No. 5,279,771 US Pat. No. 5,419,797 US Pat. No. 5,630,904 Japanese Patent No. 3,871,257 Japanese Patent No. 3513491 Japanese Patent No. 4147320

  With the new technologies disclosed in Patent Documents 4 to 6, the corrosion resistance of metals in the semiconductor substrate cleaning composition has been dramatically increased. However, the present inventors have continued research and development for the purpose of achieving higher performance. In particular, a search was made for a cleaning composition that exhibits high corrosion resistance of a metal in a substantially neutral region where a specific cleaning agent such as a hydroxylamine compound exhibits high detergency.

  The present invention solves a problem specific to a cleaning composition containing a specific cleaning agent adjusted to be substantially neutral, prevents corrosion of a metal layer of a semiconductor substrate, particularly titanium nitride, and a manufacturing process thereof It is an object of the present invention to provide a cleaning composition capable of sufficiently removing plasma etching residues and ashing residues generated in the above, a cleaning method using the same, and a semiconductor device manufacturing method. Another object of the present invention is to provide a cleaning composition that can realize cost reduction and environmental compatibility derived from an aqueous cleaning composition, a cleaning method using the same, and a semiconductor device manufacturing method.

（式中、Ｒ^１は水素原子または炭素数１〜４のアルキル基を表す。Ｒ^２、Ｒ^３、及びＲ^４はそれぞれ独立に水素原子、炭素数１〜４のアルキル基、アリール基、またはベンジル基を表す。）
（２）前記一般式（Ｉ）で表わされる化合物がイミダゾール、Ｎ−メチルイミダゾール、２−メチルイミダゾール、２−エチル−４−メチルイミダゾール、２−フェニル−４−メチルイミダゾール、２−フェニルイミダゾールであることを特徴とする（１）に記載の洗浄組成物。
（３）前記一般式（Ｉ）で表わされる化合物がイミダゾールであることを特徴とする（２）に記載の洗浄組成物。
（４）前記酸性有機化合物が、１官能性、２官能性、３官能性、又は４官能性の有機酸であることを特徴とする（１）〜（３）のいずれか１項に記載の洗浄組成物。
（５）前記酸性有機化合物が、乳酸、クエン酸、ギ酸、シュウ酸、酢酸、プロピオン酸、マロン酸、コハク酸、グルタル酸、マレイン酸、フマル酸、フタル酸、グリコール酸、サリチル酸、酒石酸、及びリンゴ酸よりなる群から選ばれた少なくとも１つの化合物であることを特徴とする（１）〜（４）のいずれか１項に記載の洗浄組成物。
（６）前記塩基性有機化合物が、有機アミン及び第４級アンモニウム水酸化物よりなる群から選ばれた少なくとも１つの化合物であることを特徴とする（１）〜（５）のいずれか１項に記載の洗浄組成物。
（７）前記塩基性有機化合物が、水酸基を有しない有機アミンであることを特徴とする（１）〜（６）のいずれか１項に記載の洗浄組成物。
（８）前記塩基性有機化合物が、テトラアルキルアンモニウム水酸化物であることを特徴とする（１）〜（６）のいずれか１項に記載の洗浄組成物。
（９）前記洗浄剤が、ヒドロキシルアミン、ヒドロキシルアミン硫酸塩、ヒドロキシルアミン塩酸塩、ヒドロキシルアミン硝酸塩、及びヒドロキシルアミンリン酸塩からなる群より選ばれた少なくとも１つの化合物であることを特徴とする（１）〜（８）のいずれか１項に記載の洗浄組成物。
（１０）さらに水溶性有機溶剤を含有することを特徴とする（１）〜（９）のいずれか１項に記載の洗浄組成物。
（１１）さらにアミノ基含有カルボン酸を含有することを特徴とする（１）〜（１０）のいずれか１項に記載の洗浄組成物。
（１２）前記アミノ基含有カルボン酸がヒスチジン及び／又はアルギニンである（１１）に記載の洗浄組成物。
（１３）さらに洗浄組成物の全質量に対して０．１質量％以上０．５質量％未満の酸性無機化合物を含有する、（１）〜（１２）のいずれか１項に記載の洗浄組成物。
（１４）前記酸性無機化合物が、リン酸、ホウ酸、六フッ化リン酸、リン酸アンモニウム、ホウ酸アンモニウム、及び六フッ化リン酸アンモニウムからなる群より選ばれた少なくとも１つの化合物である、（１３）に記載の洗浄組成物。
（１５）前記酸性無機化合物が、リン酸及び／又はその塩である、（１４）に記載の洗浄組成物。
（１６）半導体素子製造工程におけるプラズマエッチング残渣及び／又はアッシング残渣除去用の洗浄液として特に適した（１）〜（１５）のいずれか１項に記載の洗浄組成物。
（１７）洗浄される半導体基板が、露出したアルミニウムの層、銅の層、又は窒化チタンの層を含むことを特徴とする（１）〜（１６）のいずれか１項に記載の洗浄組成物。
（１８）半導体基板上のプラズマエッチング残渣及び／又はアッシング残渣を（１）〜（１７）のいずれか１項に記載の洗浄組成物で洗浄することを特徴とする洗浄方法。
（１９）前記洗浄処理を５０〜９０℃の温度で行うことを特徴とする（１８）に記載の洗浄方法。
（２０）（ａ）（ａ−１）半導体基板に対してプラズマエッチングを行うエッチング工程、及び／又は、（ａ−２）半導体基板上のレジストに対してアッシングを行うアッシング工程、並びに、
（ｂ）（１）〜（１７）のいずれか１項に記載の洗浄組成物により、前記エッチング工程及び／又は前記アッシング工程において前記半導体基板上に形成されたプラズマエッチング残渣及び／又はアッシング残渣を洗浄除去する洗浄工程
を含むことを特徴とする半導体素子の製造方法。 (1) Water, a cleaning agent, a basic organic compound, an acidic organic compound, and a nitrogen-containing aromatic cyclic compound represented by the following general formula (I) were contained and adjusted to be substantially neutral. A cleaning composition for a semiconductor substrate.

(Wherein R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ² , R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group, or Represents a benzyl group.)
(2) The compound represented by the general formula (I) is imidazole, N-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2-phenylimidazole. The cleaning composition as described in (1) above.
(3) The cleaning composition according to (2), wherein the compound represented by the general formula (I) is imidazole.
(4) The acidic organic compound is a monofunctional, difunctional, trifunctional, or tetrafunctional organic acid according to any one of (1) to (3), Cleaning composition.
(5) The acidic organic compound is lactic acid, citric acid, formic acid, oxalic acid, acetic acid, propionic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, glycolic acid, salicylic acid, tartaric acid, and The cleaning composition according to any one of (1) to (4), wherein the cleaning composition is at least one compound selected from the group consisting of malic acid.
(6) The basic organic compound is at least one compound selected from the group consisting of organic amines and quaternary ammonium hydroxides, any one of (1) to (5) The cleaning composition according to 1.
(7) The cleaning composition according to any one of (1) to (6), wherein the basic organic compound is an organic amine having no hydroxyl group.
(8) The cleaning composition according to any one of (1) to (6), wherein the basic organic compound is a tetraalkylammonium hydroxide.
(9) The cleaning agent is at least one compound selected from the group consisting of hydroxylamine, hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine nitrate, and hydroxylamine phosphate ( The cleaning composition according to any one of 1) to (8).
(10) The cleaning composition according to any one of (1) to (9), further comprising a water-soluble organic solvent.
(11) The cleaning composition according to any one of (1) to (10), further comprising an amino group-containing carboxylic acid.
(12) The cleaning composition according to (11), wherein the amino group-containing carboxylic acid is histidine and / or arginine.
(13) The cleaning composition according to any one of (1) to (12), further comprising an acidic inorganic compound of 0.1% by mass or more and less than 0.5% by mass with respect to the total mass of the cleaning composition. object.
(14) The acidic inorganic compound is at least one compound selected from the group consisting of phosphoric acid, boric acid, hexafluorophosphoric acid, ammonium phosphate, ammonium borate, and ammonium hexafluorophosphate. The cleaning composition as described in (13).
(15) The cleaning composition according to (14), wherein the acidic inorganic compound is phosphoric acid and / or a salt thereof.
(16) The cleaning composition according to any one of (1) to (15), which is particularly suitable as a cleaning liquid for removing plasma etching residue and / or ashing residue in a semiconductor element manufacturing process.
(17) The cleaning composition according to any one of (1) to (16), wherein the semiconductor substrate to be cleaned includes an exposed aluminum layer, a copper layer, or a titanium nitride layer. .
(18) A cleaning method comprising cleaning a plasma etching residue and / or an ashing residue on a semiconductor substrate with the cleaning composition according to any one of (1) to (17).
(19) The cleaning method according to (18), wherein the cleaning process is performed at a temperature of 50 to 90 ° C.
(20) (a) (a-1) an etching step of performing plasma etching on the semiconductor substrate, and / or (a-2) an ashing step of performing ashing on the resist on the semiconductor substrate, and
(B) The plasma etching residue and / or the ashing residue formed on the semiconductor substrate in the etching step and / or the ashing step by the cleaning composition according to any one of (1) to (17) A method of manufacturing a semiconductor device, comprising a cleaning step of cleaning and removing.

The cleaning composition of the present invention prevents corrosion of a metal layer of a semiconductor substrate, particularly titanium nitride, and enables sufficient removal of plasma etching residues and ashing residues generated in the manufacturing process. In addition to the above advantages, it is possible to realize cost reduction and environmental compatibility derived from the aqueous cleaning composition.
Furthermore, by the cleaning method and the semiconductor device manufacturing method of the present invention using the cleaning composition, a high-quality semiconductor device can be manufactured at low cost while realizing environmental compatibility.

It is process explanatory drawing which shows a part of manufacturing process of the semiconductor element which shows one embodiment in use of the cleaning composition of this invention. It is process explanatory drawing which shows a part of manufacturing process of the semiconductor element which shows another embodiment in use of the cleaning composition of this invention. It is process explanatory drawing which shows a part of manufacturing process of the semiconductor element which shows another embodiment in use of the cleaning composition of this invention roughly.

  The cleaning composition of the present invention contains water (a), the cleaning agent (b), the basic organic compound (c), and the acidic organic compound (d), and is adjusted to be substantially neutral. The cleaning composition further comprises a specific nitrogen-containing aromatic cyclic compound (e) represented by the general formula (I). This achieves both extremely high residue cleaning power and metal corrosion prevention. The action mechanism is estimated as follows.

  First, selection of pH is very important in the present invention, and this point will be described. When a specific compound such as hydroxylamine is used as a cleaning agent, there are some cases where the cleaning performance falls when the pH of the cleaning composition is in an acidic region (see Japanese Patent Application No. 2010-11623). When considering only the cleaning performance of the residue, the pH should be 7 or higher, and usually the higher the pH, the better the cleaning performance. However, if the pH is too high, the metal layer of the semiconductor substrate is corroded, and if the pH exceeds 9, satisfactory anticorrosion performance may not be achieved.

  In recent years, the structure and application members of semiconductor elements are further diversified, and demands for miniaturization and fine wiring are increasing. Reflecting such a situation, there is a case where strict response to the corrosion prevention property of the metal layer is required even in the cleaning in the manufacturing process of the semiconductor substrate. Considering this, it is possible to increase the amount of the acidic compound and lower the pH of the cleaning composition to increase the anticorrosive property. However, in such a cleaning composition using the specific cleaning agent, a reduction in cleaning power is inevitable. In the present invention, a configuration has been adopted in which the dilemma is overcome, the pH is maintained in a neutral range, and a specific nitrogen-containing aromatic cyclic compound is further contained in the cleaning composition. As a result, it was further discovered that the high detergency of the cleaning agent substantially obtained in the neutral region can be maintained as it is, and the corrosion resistance of the metal member, particularly titanium nitride, can be improved at the same time. . The principle of its action includes an unclear point. For example, when describing a metal nitride, a nitrogen-containing aromatic cyclic compound is coordinated to a metal atom such as titanium in a specific state to suppress oxidation of the metal atom, It is thought that corrosion is prevented. Further, it is considered that the nitrogen-containing aromatic cyclic compound is not protonated at neutral pH, and can coordinate to the metal atom particularly effectively. Hereinafter, preferred embodiments of a cleaning composition, a cleaning method using the same, and a method for manufacturing a semiconductor device of the present invention will be described in detail with reference to some drawings.

[Residue]
In the manufacturing process of a semiconductor element, there is a step of etching a metal layer on a semiconductor substrate by plasma etching using a resist pattern or the like as a mask. Specifically, a metal layer, a semiconductor layer, an insulating layer, or the like is etched to pattern the metal layer or the semiconductor layer, or an opening such as a via hole or a wiring groove is formed in the insulating layer. In the plasma etching, a residue derived from a resist used as a mask, a metal layer to be etched, a semiconductor layer, and an insulating layer is generated on the semiconductor substrate. In the present invention, such a residue generated by plasma etching is referred to as “plasma etching residue”.

  Further, the resist pattern used as a mask is removed after etching. For removing the resist pattern, as described above, a wet method using a stripper solution or a dry method by ashing using, for example, plasma or ozone is used. In the ashing, a residue obtained by altering a plasma etching residue generated by plasma etching or a residue derived from a resist to be removed is generated on the semiconductor substrate. In the present invention, the residue generated by ashing in this way is referred to as “ashing residue”. In addition, a generic term for what should be removed by cleaning such as plasma etching residue and ashing residue on the semiconductor substrate may be simply referred to as “residue”.

  It is preferable that the plasma etching residue and the ashing residue, which are the residues after etching (Post Etch Residue), are removed by cleaning using a cleaning composition. The cleaning composition of the present invention is suitable for removal of plasma etching residue generated by plasma etching and / or ashing residue generated by ashing. The cleaning composition of the present invention can also be applied to a cleaning method (use) for removing plasma etching residues and / or ashing residues. Especially, it is preferable to use it for removing a plasma etching residue and an ashing residue after plasma ashing performed following plasma etching.

[Cleaning composition]
As described above, the cleaning composition of the present invention contains a cleaning agent, a basic organic compound, and an acidic organic compound in water, and is adjusted to be substantially neutral. Hereinafter, each component will be described in order.

(water)
The cleaning composition of the present invention is preferably an aqueous solution in which water is applied as a medium and each component is uniformly dissolved. The water content is preferably 50 to 99.5% by mass relative to the total mass of the cleaning composition. As described above, a cleaning composition containing water as a main component (50% by mass or more) is sometimes referred to as an aqueous cleaning composition, and is inexpensive and environmentally friendly compared to a cleaning composition having a high ratio of organic solvent. It is preferable in terms of gentleness. The water may be an aqueous medium containing a dissolved component as long as the effects of the present invention are not impaired, or may contain an unavoidable minor mixed component. Of these, distilled water, ion-exchanged water, or water subjected to purification treatment such as ultrapure is preferable, and ultrapure water used for semiconductor manufacturing is particularly preferable.

(Washing soap)
The cleaning composition of the present invention contains a cleaning agent, which is preferably a nitrogen-containing compound cleaning agent (a cleaning agent composed of a compound containing a nitrogen atom). Among them, the cleaning agent is an amine compound cleaning agent (an amine compound is a general term for compounds including ammonia, primary amine, secondary amine, tertiary amine, quaternary ammonium salt, oxime, ═N—H, and the like. preferably) is, more preferably an amine compound detergents having -NH _2, and particularly preferably an amine compound cleaner having an oxygen atom in having -NH ₂ and the molecule. At this time, part or all may be amine oxide. Specifically, a hydroxylamine (pKa = 6) compound and a carbazate described later are preferable. The salt is preferably an inorganic acid salt or an organic acid salt, more preferably a salt of an inorganic acid formed by bonding a nonmetal such as Cl, S, N, and P with hydrogen, hydrochloric acid, Particularly preferred is a salt of either sulfuric acid or nitric acid.

  The hydroxylamine salts used to form the cleaning composition of the present invention include hydroxylamine nitrate (also referred to as HAN), hydroxylamine sulfate (also referred to as HAS), hydroxylamine phosphate, hydroxyl An amine hydrochloride etc. can be illustrated. An organic acid salt of hydroxylamine can also be used in the cleaning composition, and examples thereof include hydroxylamine citrate and hydroxylamine oxalate. Among these salts of hydroxylamine, inorganic acid salts such as hydroxylamine nitrate, hydroxylamine sulfate, hydroxylamine phosphate, and hydroxylamine hydrochloride are preferable because they are inert to metals such as aluminum, copper, and titanium. In particular, hydroxylamine nitrate and hydroxylamine sulfate are preferred. Among them, the cleaning agent is preferably hydroxylamine or hydroxylamine sulfate. These hydroxylamine compounds can be used singly or in combination of two or more.

In the present invention, the cleaning agent is not limited to the above-mentioned hydroxyamine compound, and a compound or composition having a desired action can be appropriately selected and used. Typically, what functions as a nucleophile is mentioned as an effect | action for making a residue component easy to melt | dissolve. From the viewpoint, the following can be exemplified.
-Preferably a nucleophile having a pKa of 5 or more and 8 or less (more preferably a nucleophile having a pKa of 5.5 or more and 7 or less)
・ Nucleophile with α effect (higher nucleophilicity than expected from pKa when it has an electron donor atom at α position) ・ Nucleophile with high ER (etching rate) of TiO ₂

  In the present specification, the term “compound” is used to mean a salt and an ion thereof in addition to the compound itself, and typically means the compound and / or a salt thereof. Therefore, the above hydroxylamine compound is meant to include hydroxylammonium ion, hydroxylamine, and / or a salt thereof, and typically means hydroxylamine and / or a salt thereof.

  The hydroxylamine salts used to form the cleaning composition of the present invention include hydroxylamine nitrate (also referred to as HAN), hydroxylamine sulfate (also referred to as HAS), hydroxylamine phosphate, hydroxyl An amine hydrochloride etc. can be illustrated. An organic acid salt of hydroxylamine can also be used in the cleaning composition, and examples thereof include hydroxylamine citrate and hydroxylamine oxalate. Among these salts of hydroxylamine, inorganic acid salts such as hydroxylamine nitrate, hydroxylamine sulfate, hydroxylamine phosphate, and hydroxylamine hydrochloride are preferable because they are inert to metals such as aluminum, copper, and titanium. In particular, hydroxylamine nitrate and hydroxylamine sulfate are preferred. Among them, the cleaning agent is preferably hydroxylamine or hydroxylamine sulfate. These hydroxylamine compounds can be used singly or in combination of two or more.

  Other detergents include water-soluble hydrazino carboxylic acid esters (also known as carbazates or carbazates). Examples of suitable hydrazinocarboxylic acid esters include methyl carbazate, ethyl carbazate, propyl carbazate, isopropyl carbazate, butyl carbazate, tertiary butyl carbazate, pentyl carbazate, decyl carbazate, pentadecyl carbazate, Examples include, but are not limited to, eicosyl carbazate, benzyl carbazate, phenyl carbazate, and 2-hydroxyethyl carbazate.

  The cleaning agent is preferably contained within a range of about 0.01 to about 30% by mass, and more preferably 0.1 to 15% by mass with respect to the total mass of the cleaning composition of the present invention. The cleaning agent particularly has an effect of facilitating removal of plasma etching residues and preventing corrosion of the metal substrate. By setting it as the said range, a high detergency is exhibited especially suitably, and it is preferable at the point from which the favorable metal corrosion prevention effect is fully acquired.

(Basic organic compounds)
The cleaning composition of the present invention contains a basic organic compound. In the present invention, the “basic organic compound” means that the cleaning agent is not included, and the same compound as the cleaning agent is not adopted as the “basic organic compound”. The basic organic compound preferably has carbon and nitrogen as constituent elements, and more preferably has an amino group. Specifically, the basic organic compound is preferably at least one compound selected from the group consisting of organic amines and quaternary ammonium hydroxides. The organic amine means an amine containing carbon as a constituent element.

The number of carbon atoms of the basic organic compound is preferably 4 to 30, and more preferably 6 to 16 from the viewpoint of boiling point or solubility in water.
Examples of the organic amine used as the basic organic compound of the cleaning composition of the present invention include monoethanolamine, diethanolamine, triethanolamine, diethylene glycolamine, alkanolamines such as N-hydroxylethylpiperazine, and / or ethylamine, benzylamine. , Diethylamine, n-butylamine, 3-methoxypropylamine, tert-butylamine, n-hexylamine, cyclohexylamine, n-octylamine, 2-ethylhexylamine, o-xylenediamine, m-xylylenediamine, 1-methylbutylamine Hydroxy acids such as ethylenediamine (EDA), 1,3-propanediamine, 2-aminobenzylamine, N-benzylethylenediamine, diethylenetriamine and triethylenetetramine It includes organic amine having no. From the viewpoint of preventing metal corrosion, an organic amine having no hydroxyl group is preferred to an alkanolamine. Further, ethylenediamine, 1,3-propanediamine, o-xylenediamine, and m-xylylenediamine are particularly preferable because they can coordinate with a metal.

  The quaternary ammonium hydroxide used as the basic organic compound of the cleaning composition of the present invention is preferably a tetraalkylammonium hydroxide, and a tetraalkylammonium substituted with a lower (1 to 4 carbon) alkyl group. More preferred are hydroxides, and specific examples include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), and tetrabutylammonium hydroxide (TBAH). . Furthermore, examples of the quaternary ammonium hydroxide include trimethylhydroxyethylammonium hydroxide (choline), methyltri (hydroxyethyl) ammonium hydroxide, tetra (hydroxyethyl) ammonium hydroxide, and benzyltrimethylammonium hydroxide (BTMAH). In addition, a combination of ammonium hydroxide and one or more quaternary ammonium hydroxides can also be used. Among these, TMAH, TEAH, TPAH, TBAH, and choline are more preferable, and TMAH and TBAH are particularly preferable.

  These organic amines and quaternary ammonium hydroxides can be used singly or in combination of two or more. The content of the basic organic compound is preferably about 0.01 to about 20.0% by mass, and 1.0 to 10.0% by mass with respect to the total mass of the cleaning composition of the present invention. It is more preferable. By setting it as the above range, it is preferable because the pH adjustment action can be sufficiently exhibited and the high detergency and the metal corrosion prevention effect can be achieved in correspondence with the content of the hydroxyamine compound described above.

(Acid organic compounds)
The cleaning composition of the present invention contains at least one acidic organic compound, and the acidic organic compound is preferably a monofunctional, difunctional, trifunctional, or tetrafunctional organic acid. Acidic organic compounds serve as corrosion inhibitors for metals.
Among the acidic organic compounds, carboxylic acid compounds are preferable because they effectively prevent metal corrosion of aluminum, copper, and alloys thereof, and hydroxycarboxylic acid compounds having a hydroxyl group are particularly effective in preventing metal corrosion. preferable. Carboxylic acid compounds have a chelating effect on these metals. Preferred carboxylic acid compounds include monocarboxylic acid compounds and polycarboxylic acid compounds. Carboxylic acid compounds include, but are not limited to, formic acid, acetic acid, propionic acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, 1,2, 3-Benzenetricarboxylic acid, glycolic acid, lactic acid, citric acid, salicylic acid, tartaric acid, gluconic acid, diglycolic acid, malic acid, acetohydroxamic acid, benzohydroxamic acid, salicylhydroxamic acid, phthalhydroxamic acid, benzoic acid, dihydroxybenzoic acid And mixtures thereof. Among these, hydroxycarboxylic acids such as citric acid, malic acid, tartaric acid, glycolic acid, gluconic acid, and lactic acid can be preferably used.
In addition, it is preferable that a carboxylic acid compound has only C, H, and O as a constituent element, and it is more preferable that it does not have an amino group.

  These acidic organic compounds can be used singly or in combination of two or more, but it is preferable to use two or more in combination from the viewpoint of effectively preventing metal corrosion. The acidic organic compound is preferably added between about 0.01 to about 20.0% by weight, more preferably about 0.05 to about 20.0% by weight, based on the total weight of the cleaning composition of the present invention. %, More preferably 0.1 to 10.0% by mass. By setting it as the said range, it respond | corresponds with the said preferable content of a hydroxylamine compound and a basic organic compound, and it is preferable at the point from which a favorable metal corrosion prevention effect is fully acquired, without reducing a detergency.

(Amino group-containing carboxylic acid)
The cleaning composition of the present invention may contain an amino group-containing carboxylic acid. An amino group-containing carboxylic acid is preferable in terms of efficiently preventing metal corrosion.
Examples of amino group-containing carboxylic acids include glycine, alanine, asparagine, aspartic acid, arginine, glutamine, glutamic acid, histidine, serine, cysteine, tyrosine, phenylalanine, and / or an aminopolycarboxylate group consisting of the following: ethylenediamine Tetraacetate (EDTA), Diethylenetriaminepentaacetic acid (DTPA), Hydroxyethylethylenediaminetriacetate (HEDTA), Dihydroxyethylethylenediaminetetraacetate (DHEDDA), Nitriloate acetate (NTA), Hydroxyethyliminodiacetate (HIDA) ), Β-alanine diacetate, aspartate diacetate, methylglycine diacetate, iminodisuccinate, serine diacetate, hydroxyiminodisuccinate, dihydroxyethyl Lysine salt, aspartate, glutamate, etc.}, hydroxycarboxylate group comprising {hydroxyacetate, tartrate, citrate, gluconate, etc.}, cyclocarboxylate group {pyromellitic acid comprising Salt, benzopolycarboxylate, cyclopentanetetracarboxylate, etc.}, ether carboxylate group consisting of {carboxymethyl tarturonate, carboxymethyloxysuccinate, oxydisuccinate, tartaric acid monosuccinate, tartaric acid disuccinate Etc.}, other carboxylate group consisting of {maleic acid derivatives, oxalates, etc.}, organic carboxylic acid (salt) polymer group consisting of {acrylic acid polymer and copolymer (acrylic acid-allyl alcohol copolymer) Polymer, acrylic acid-maleic acid copolymer, hydroxy Acrylic 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, Polymers and copolymers of monomers such as succinic acid, aspartic acid, glutamic acid}, glyoxylic acid polymer comprising the following, polysaccharide group {starch, cellulose, amylose, pectin, carboxymethylcellulose, etc.}, phosphonate comprising Group {methyl diphosphonate, aminotrismethylene phosphonate, ethylidene diphosphonate, 1-hydroxyethylidene-1,1-diphosphonate, ethylamino bismethylene phosphonate, ethylenediamine bismethylene phosphonate, ethylenediamine Tetramethylene phosphonate, hexamethyle Diamine tetramethylene phosphonic acid, propylene diamine tetra methylene phosphonates, diethylene triamine penta methylene phosphonates, and triethylene tetramine hexamethylene phosphonates and tetraethylenepentamine heptamethylene phosphonates} 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.
Among these amino group-containing carboxylic acids, arginine, histidine, glutamine, EDTA, DTPA, and HIDA are preferable, and arginine and histidine are more preferable.
These amino group-containing carboxylic acids can be used singly or in combination of two or more.

  In the cleaning composition of the present invention, when the amino group-containing carboxylic acid is contained, the addition amount can be appropriately selected, but is 0.01 to 5.0% by mass with respect to the total mass of the cleaning composition of the present invention. It is preferable that it is 0.01-3 mass%.

(Acid inorganic compounds)
The cleaning composition of the present invention may contain an acidic inorganic compound. The use of an acidic inorganic compound is preferable in terms of inhibiting corrosion of metals, particularly Al.
Examples of the acidic inorganic compound include a phosphoric acid compound and a boric acid compound, preferably phosphoric acid and phosphate. Specific examples include phosphoric acid, boric acid, hexafluorophosphoric acid, ammonium phosphate, ammonium borate, and ammonium hexafluorophosphate. These may be used alone or in combination of two or more.
In the cleaning composition of the present invention, when an acidic inorganic compound is contained, the addition amount can be appropriately selected, but from the viewpoint of the temporal stability of the cleaning composition, the total mass of the cleaning composition of the present invention is The content is preferably about 0.1% by mass or more and less than 0.5% by mass, and more preferably 0.2 to 0.4% by mass.

(PH of cleaning composition)
The cleaning composition of the present invention is adjusted to be substantially neutral. In the present invention, substantially neutral means that the composition is in the vicinity of pH 7 as long as the desired effect of the cleaning composition is exhibited. Specifically, the pH is preferably 5 to 10, and more preferably 6 to 8. When the pH is within the above numerical range, it is possible to achieve both corrosion prevention of the metal while sufficiently removing the photoresist, the antireflection film, the etching residue, and the ashing residue. This pH range is preferable because the residue when the silicon oxide and the metal layer are plasma etched to form a via pattern can be sufficiently removed. As a measuring method of pH, it can measure using a commercially available pH meter. In the present invention, unless otherwise specified, pH refers to a value measured under the conditions shown in the examples. In order to adjust the cleaning composition to a predetermined pH, titration can be performed by adjusting the amount of the basic organic compound added.

(Nitrogen-containing aromatic cyclic compound)
The cleaning composition of the present invention contains a nitrogen-containing aromatic cyclic compound represented by the general formula (I) in addition to the basic component.

In general formula (I), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom.
R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group (preferably having 6 to 12 carbon atoms, such as phenyl or naphthyl), or a benzyl group, preferably hydrogen. Is an atom.
Preferred examples of the compound represented by the general formula (I) include imidazole, N-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, and 2-phenylimidazole. Particularly preferably, imidazole is used.

  The cyclic compound mentioned above can be used individually by 1 type or in mixture of 2 or more types. The nitrogen-containing aromatic cyclic compound represented by the general formula (I) is preferably added in an amount of 0.01 to 20% by mass, more preferably 0.1 to the total mass of the cleaning composition of the present invention. -10 mass% is added, More preferably, 0.5-5 mass% is added. By setting it as the said range, it is preferable at the point from which a sufficient metal corrosion prevention effect, especially the corrosion prevention effect of titanium nitride are fully acquired, maintaining high detergency. By increasing the content of the cyclic compound, it becomes possible to further improve the corrosion resistance.

(Water-soluble organic solvent)
The cleaning composition of the present invention may contain a water-soluble organic solvent. The water-soluble organic solvent may be sufficient for preventing corrosion. For example, methyl alcohol, ethyl alcohol, 1-propyl alcohol, 2-propyl alcohol, 2-butanol, ethylene glycol, propylene glycol, glycerin, 1,6-hexanediol, cyclohexanediol, sorbitol, xylitol, 2-methyl-2, Alcohol solvents such as 4-pentanediol, 1,3-butanediol, 1,4-butanediol, ethylene glycol monomethyl ether, diethylene glycol, dipropylene glycol, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol, polyethylene glycol , Propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol Ether solvents such as methyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether, formamide, monomethylformamide, dimethylformamide, acetamide, monomethylacetamide, dimethylacetamide, monoethylacetamide, diethylacetamide, amide solvents such as N-methylpyrrolidone, dimethyl Examples thereof include sulfur-containing solvents such as sulfone, dimethyl sulfoxide and sulfolane, and lactone solvents such as γ-butyrolactone and δ-valerolactone. Of these, alcohols and ethers are preferable, and 1,6-hexanediol, diethylene glycol, propylene glycol, dipropylene glycol, propylene glycol monomethyl ether, and dipropylene glycol monomethyl ether are more preferable. 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 composition is preferably used at a concentration of 0 to 40% by mass, more preferably 0 to 20% by mass with respect to the total mass of the cleaning composition. The More preferably, it is used at a concentration of 0.01 to 15% by mass. By adding a water-soluble organic solvent to the cleaning composition, it is possible to improve the detergency of the carbon-rich residue, and it is also preferable from the viewpoint of enhancing the corrosion resistance of the metal film.

(Other ingredients)
-Surfactant Moreover, the cleaning composition of this invention may contain surfactant. As the surfactant, nonionic, anionic, cationic surfactants, and amphoteric surfactants can be used. The content of the surfactant in the cleaning composition is preferably 0.0001 to 5 mass%, more preferably 0.0001 to 1 mass%, based on the total mass of the cleaning composition. It is preferable because the viscosity of the cleaning composition can be adjusted by adding a surfactant to the cleaning composition, and the wettability to the object to be cleaned can be improved. It is preferable also from the point of being more excellent. Such surfactants are generally commercially available. These surfactants may be used alone or in combination.

-Corrosion inhibitor The cleaning composition of this invention may contain a corrosion inhibitor. In the present invention, the term “corrosion inhibitor” means that the nitrogen-containing aromatic cyclic compound represented by the general formula (I) is not included, and the nitrogen-containing aroma represented by the general formula (I) as the “corrosion inhibitor”. Group cyclic compounds are never employed. The corrosion inhibitor is preferably a heterocyclic compound, and more preferably benzotriazole and its derivatives. Examples of the derivatives include 5,6-dimethyl-1,2,3-benzotriazole (DBTA), 1- (1,2-dicarboxyethyl) benzotriazole (DCEBTA), 1- [N, N-bis (hydroxy). Ethyl) aminomethyl] benzotriazole (HEABTA) and 1- (hydroxymethyl) benzotriazole (HMBTA) are preferred. The corrosion inhibitor used in the present invention may be used alone or in combination of two or more. Moreover, the corrosion inhibitor used in the present invention can be synthesized according to a conventional method, or a commercially available product may be used. The addition amount of the corrosion inhibitor is preferably 0.01% by mass or more and 0.2% by mass or less, and more preferably 0.05% by mass or more and 0.2% by mass or less.

  Identification of each component in the composition may be appropriately performed by a conventional method. For example, ion chromatography, H-NMR, or a spectral absorptiometer may be used.

[Cleaning method]
Next, a preferred embodiment of the cleaning method of the present invention will be described. The cleaning method of the present embodiment includes a cleaning step of cleaning the plasma etching residue and / or ashing residue formed on the semiconductor substrate using the cleaning composition of the present invention. In this cleaning method, in the semiconductor substrate, for example, a metal layer such as a via or a wiring, in that the high cleaning power and the corrosion resistance of the metal layer, which are the advantages of the above-described cleaning composition of the present invention, are effectively exhibited. Is preferably formed and exposed, and the residue is deposited thereon. As a metal layer, it is more preferable that it contains titanium nitride, aluminum, or copper since the effect of the cleaning composition of the present invention is exhibited. The aspect of cleaning in the cleaning step is not particularly limited as long as it is an aspect in which the surface of the semiconductor substrate on which at least the plasma etching residue and / or the ashing residue is formed is brought into contact with the cleaning composition of the present invention. An embodiment in which the semiconductor substrate is immersed in the cleaning composition of the present invention is preferred.

  The cleaning method of the present embodiment is preferably performed in a state where the cleaning composition is heated in the cleaning step. Although the heating temperature in the washing | cleaning process of a cleaning composition is not specifically limited, It is preferable that it is 50-90 degreeC, and it is more preferable that it is 55-80 degreeC. Therefore, according to this embodiment, since the composition is heated and used in the above range, it is preferable that the content component does not decompose, volatilize, or react at that temperature. . Further, it is preferable that the change in pH of the composition due to temperature is not large, and in the cleaning composition of the above-described embodiment, the change in pH from room temperature to the temperature at the time of cleaning is not large and is substantially neutral. ing.

[Method of manufacturing semiconductor element]
Next, a preferred embodiment in the method for manufacturing a semiconductor device of the present invention will be described in detail. The manufacturing method of the present embodiment includes (a) (a-1) an etching process for performing plasma etching on a semiconductor substrate, and / or (a-2) an ashing process for performing ashing on a resist on the semiconductor substrate. And (b) a cleaning step of cleaning and removing plasma etching residues and / or ashing residues formed on the semiconductor substrate in the etching step and / or the ashing step by the cleaning composition. Specifically, it is preferable that the manufacturing method applies the cleaning composition in cleaning the semiconductor substrate after forming the via hole or the wiring. The “semiconductor substrate” in the present invention refers to all intermediate processed products in the middle of manufacturing a semiconductor element (final product), and is not limited to a silicon wafer, for example, an interlayer on a silicon wafer unless otherwise specified. This means that an insulating film, a tungsten plug, a via hole, a wiring or the like is formed.

(First embodiment)
FIG. 1 is a process cross-sectional view illustrating an outline of a semiconductor device manufacturing method according to a first embodiment of the present invention. Although FIGS. 1 to 3 are shown assuming a cross section, they are shown with hatching omitted to avoid complexity in the drawings.
Step a: See FIG. 1A First, transistors and other elements and one or more layers of wiring are formed on the silicon wafer 10 by a normal semiconductor element manufacturing process. Next, an interlayer insulating film is formed on the wafer 10 on which elements and the like are formed. Next, an Al alloy film 12 having a film thickness of, for example, about 500 nm and a titanium nitride film 14 having a film thickness of, for example, about 50 nm are sequentially stacked on the entire surface by, eg, CVD (Chemical Vapor Deposition). In this way, a conductor film formed by sequentially laminating the Al alloy film 12 and the titanium nitride film 14 is formed. The Al alloy film 12 is an alloy film of Al and Cu containing, for example, 0.1 to 5% by mass of Cu.

  Next, the conductor film is patterned by photolithography and dry etching. Thus, the wiring 16 composed of the Al alloy film 12 and the titanium nitride film 14 is formed. Further, a silicon oxide film 18 having a thickness of, for example, about 500 nm is formed on the entire surface by, eg, CVD. Next, the surface of the silicon oxide film 18 is polished by, for example, a CMP (Chemical Mechanical Polishing) method, and the surface of the silicon oxide film 18 is planarized. Through the above procedure, the semiconductor substrate a shown in FIG.

Step b: See FIG. 1B Next, a photoresist film R having a via pattern is formed on the silicon oxide film 18 by photolithography. Subsequently, the silicon oxide film 18 is etched by plasma etching using this photoresist film as a mask. At this time, the upper portion of the titanium nitride film 14 under the silicon oxide film 18 is also etched. Thus, a via hole (via pattern A) 20 reaching the titanium nitride film 14 of the wiring 16 is formed in the silicon oxide film 18 (see FIG. 1B). Plasma etching of the upper portions of the silicon oxide film 18 and the titanium nitride film 14 can be performed using a known method.

Step c: See FIG. 1C Next, the photoresist film used as a mask is removed by ashing using, for example, plasma or oxygen. Ashing of the photoresist film can be performed using a known method. In the plasma etching for forming the via hole 20 and the ashing for removing the photoresist film, the modified photoresist film, the silicon oxide film 18 and the bottom of the via hole 20 are exposed on the substrate surface including the surface around the via hole 20. Residues (plasma etching residue and ashing residue) G derived from the titanium nitride film 14 deposited are adhered. FIG. 1c shows a state in which this residue G exists.

Step d: See FIG. 1D Therefore, after the ashing for removing the photoresist film, the wafer 10 having the via holes 20 formed thereon is cleaned with the cleaning composition according to the present embodiment. Thus, the plasma etching residue and the ashing residue attached to the surface of the wafer 10 where the via hole 20 is formed are removed. As a result, the surface of the semiconductor substrate d is brought into an extremely clean state, and the surface of each material having ideal electrical characteristics is exposed (see FIG. 1D).
Next, a tungsten film is formed on the entire surface by, eg, CVD. Further, the tungsten film is polished by CMP, for example, until the surface of the silicon oxide film 18 is exposed. Thus, a via made of tungsten is buried in the via hole 20. In this way, a high-quality semiconductor element free from the ashing residue at the element interface of the element can be obtained.

(Second Embodiment)
Next, the outline of the semiconductor device manufacturing method according to the second embodiment of the present invention will be described with reference to FIG. The semiconductor element manufacturing method according to the present embodiment is different from the semiconductor element manufacturing method according to the first embodiment in that a via hole 20 reaching the Al alloy film 12 of the wiring 16 is formed.

Step a: See FIG. 2A First, in the same manner as in the semiconductor device manufacturing method according to the first embodiment, a wiring 16 comprising an Al alloy film 12 and a titanium nitride film 14 and silicon oxide are formed on the wafer 10. A film 18 is formed (see FIG. 2A).

Step b: See FIG. 2B Next, a photoresist film having a via pattern is formed on the silicon oxide film 18 by photolithography. Subsequently, using this photoresist film as a mask, the silicon oxide film 18 and the titanium nitride film 14 are etched by plasma etching. At this time, the upper part of the Al alloy film 12 under the titanium nitride film 14 is also etched. Thus, a via hole 20 (via pattern B) reaching the Al alloy film 12 of the wiring 16 is formed in the silicon oxide film 18 and the titanium nitride film 14. Plasma etching on the silicon oxide film 18, the titanium nitride film 14, and the Al alloy film 12 can be performed using conventional methods.

Step c: See FIG. 2C Next, the photoresist film used as the mask is removed by ashing using, for example, plasma or oxygen. Ashing of the photoresist film can be performed using a known method. In the case of the present embodiment, in dry etching for forming the via hole 20 and ashing for removing the photoresist film, plasma etching residue and ashing residue are formed on the substrate surface including the surface around the via hole 20 and the wall surface of the via hole 20. Adhere to. In the present embodiment, the plasma etching residue and the ashing residue are derived not only from the altered photoresist film, silicon oxide film 18 and titanium nitride film 14 but also from the Al alloy film 12 exposed at the bottom of the via hole 20.

Step d: See FIG. 2D Therefore, after the ashing for removing the photoresist film, the wafer 10 having the via holes 20 formed thereon is cleaned with the cleaning composition according to the present embodiment. Thus, the plasma etching residue and the ashing residue attached to the surface of the wafer 10 where the via hole 20 is formed are removed. As a result, the surface of the semiconductor substrate d is in a very clean state, and the surface of each material having ideal electrical characteristics is exposed. In this embodiment, in particular, the surface of the aluminum (Al) alloy film 12 corresponding to the bottom of the via hole is also sufficiently cleaned to expose its clean surface.

  Next, vias embedded in the via holes 20 are formed in the same manner as in the semiconductor device manufacturing method according to the first embodiment. In this way, a high-quality semiconductor element free from the ashing residue at the element interface of the element can be obtained.

(Third embodiment)
Next, the outline of the method for fabricating the semiconductor device according to the third embodiment of the present invention will be described with reference to FIG.
Step (a): See FIG. 3A First, the interlayer insulating film 24 is formed on a semiconductor substrate (wafer) on which elements and the like are formed, similarly to the method for manufacturing a semiconductor element according to the first embodiment. Next, a titanium nitride film 26 with a film thickness of, for example, about 50 nm, a titanium film 28 with a film thickness of, for example, about 20 nm, an Al alloy film 30 with a film thickness of, for example, about 500 nm, and a film thickness of, for example, about 50 nm are formed on the entire surface by, eg, CVD. The titanium nitride films 32 are sequentially stacked. The Al alloy film 30 is an alloy film of Al and Cu containing 0.1 to 5% Cu, for example. The above dimensions are merely examples, and the present embodiment is not construed as being limited thereto.

Step b: See FIG. 3B Next, a photoresist film having a wiring pattern is formed on the titanium nitride film 32 by photolithography. Subsequently, using the photoresist film as a mask, the titanium nitride film 32, the Al alloy film 30, the titanium film 28, and the titanium nitride film 26 are sequentially etched by plasma etching. In this way, the titanium nitride film 32, the Al alloy film 30, the titanium film 28, and the titanium nitride film 26 are patterned to form a wiring (wiring pattern) 34 made of these conductor films.

Step c: See FIG. 3C Next, most of the photoresist film used as a mask is peeled and removed by wet treatment using a chemical solution. Subsequently, the remaining portion of the photoresist film is removed by, for example, ashing using plasma, oxygen, or the like (see FIG. 3C). In plasma etching for forming the wiring 34 and ashing for removing the remaining portion of the photoresist film, as shown in FIG. 3C, residues (plasma etching) are formed on the substrate surface including the upper surface and side surfaces of the wiring 34. Residue and ashing residue) G adheres. This residue G is derived from the altered photoresist film, titanium nitride film 32, Al alloy film 30, titanium film 28, and titanium nitride film 26.

Step d: Refer to FIG. 3D Therefore, after the ashing for removing the remaining portion of the photoresist film, the wafer 10 on which the wiring 34 is formed is cleaned with the cleaning composition according to the present invention. In this way, plasma etching residue and ashing residue adhering to the surface of the wafer 10 where the wiring 34 is formed are removed. As a result, the surface of the semiconductor substrate d is brought into a very clean state, and the surface of each material having ideal electrical characteristics is exposed (see FIG. 3D). In particular, according to this embodiment, metal corrosion in the recess (groove between the source and drain) 29 is prevented, which is preferable.

  In the above embodiment, the case where the wirings 16 and 34 including the Al alloy films 12 and 30 are formed has been described. However, the material of the wiring is not limited to that described above. As the wiring, in addition to wiring made mainly of Al made of Al or Al alloy, wiring made mainly of Cu made of Cu or Cu alloy can be formed.

  Further, the cleaning composition of the present invention can be widely used in a step of cleaning a plasma etching residue and / or an ashing residue from a semiconductor substrate including a metal layer of titanium nitride, aluminum, or copper, and aluminum or copper is a substrate for a semiconductor. It is preferable to be included in the wiring structure formed above. As described above, the cleaning liquid according to the present embodiment is effective in the semiconductor manufacturing processes of various forms and conditions, and there is no residue at the member interface of the semiconductor element manufactured through cleaning by this, and the quality is extremely high quality. A semiconductor element can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

<Examples and comparative examples>
The components shown in Table 1 below were added to water at the composition (mass%) shown therein to prepare cleaning compositions 101 to 115 (Examples). As the water, general ultrapure water used in the semiconductor manufacturing process was used. Moreover, it replaced with the component composition shown in the following Table 1 with respect to the said Example, and prepared the cleaning composition c11, c12 (comparative example), s11, s12 (reference example). In addition, the component which showed the composition (mass%) in the table | surface contained this quantity, and the basic organic compound was contained in the quantity used as the pH shown about each sample. It means that the water composition (mass%) is combined with these to become 100 mass%. The pH in the table is a value measured with F-51 (trade name) manufactured by HORIBA at room temperature (23 ° C.).

<Cleaning test>
About the said 1st and 2nd embodiment, when a via hole was formed and the pattern wafer was observed with the scanning electron microscope (SEM: Scanning Electron Microscope), the plasma etching residue and the ashing residue were recognized by both via-hole wall surfaces (FIG. 1). (See (c) and FIG. 2 (c)). In the third embodiment, after the wiring was formed, the pattern wafer was observed by SEM. As a result, plasma etching residue and ashing residue were observed on the upper and side surfaces of the wiring (see FIG. 3C).

A section (about 2 cm × 2 cm) of the pattern wafer with the residue attached is immersed in each cleaning composition adjusted to the temperature described in Table 1, and the section of the pattern wafer is immersed after the immersion time described in Tables 1 to 3. The product was taken out, immediately washed with ultrapure water, and dried with N ₂ . Observe the cross section and surface of the section of the patterned wafer after the immersion test with SEM, and evaluate the removability of the photoresist and residues (plasma etching residue and ashing residue) and the corrosivity of Al and TiN according to the following criteria. went. The evaluation results of removability and corrosivity are shown in Table 1.

<Removal of residue on the surface around the via hole>
AA: The photoresist and residue were completely removed.
A: The photoresist and residue were almost completely removed.
B: A poorly dissolved photoresist and residue remained.
C: The photoresist and residue were hardly removed.

<Corrosion of the metal layer at the bottom of the via hole>
AA: Corrosion of TiN was not observed.
A: Corrosion of TiN occurred at 1% or less with respect to the wiring.
B: Corrosion of TiN occurred at 10% or less with respect to the wiring.
C: TiN completely disappeared.

  In the third embodiment, not the surface around the via hole but the state of residue removal on the wiring side surface / upper surface was observed and evaluated. The metal layer was evaluated by Al corrosion (recess). The evaluation criteria are the same as above.

表中の略称は以下のとおりの内容を意味する。
・「％」は質量％を意味する。
・HAS:ヒドロキシルアミン硫酸塩
・CM：カルバジン酸メチル
・HA：ヒドロキシルアミン
・TMAH：テトラメチルアンモニウムヒドロキシド
・PVP：ポリビニルピロリドン
・PVA：ポリビニルアルコール
・PAA：ポリアクリル酸
1,3-BuDO：１，３−ブタンジオール
DPG：ジプロピレングリコール

Abbreviations in the table mean the following contents.
・ "%" Means mass%.
-HAS: Hydroxylamine sulfate-CM: Methyl carbazate-HA: Hydroxylamine-TMAH: Tetramethylammonium hydroxide-PVP: Polyvinylpyrrolidone-PVA: Polyvinyl alcohol-PAA: Polyacrylic acid
1,3-BuDO: 1,3-butanediol
DPG: Dipropylene glycol

Residue removal [1]: Evaluation results for residue removal on the surface around the via hole in the first embodiment Metal corrosion [1]: Evaluation results for corrosion of TiN on the bottom of the via hole in the first embodiment Residue removal [2]: Evaluation results for residue removal on the surface around the via hole in the second embodiment, metal corrosion [2]: Evaluation results for corrosion of Al in the bottom of the via hole in the second embodiment, residue removal [3]: Wiring side surface in the third embodiment・ Evaluation result for removal of residue on top surface ・ Metal corrosion [3]: Evaluation result in Al corrosion (recess) of the third embodiment

  As shown in Table 1 above, the cleaning compositions (Examples) of the present invention prevent the corrosion of metal members of a semiconductor substrate in the manufacture of various forms of semiconductor elements, and the plasma etching residue generated in the manufacturing process. It can be seen that the ashing residue can be sufficiently removed. In particular, it has an extremely high detergency and a metal corrosion prevention effect for compositions that are acidic and do not contain the nitrogen-containing aromatic cyclic compound represented by the above general formula (I) (comparative examples, compositions c11 and c12). It turns out that it is what is shown. Moreover, compared with the alkaline or acidic composition (comparative example, composition c13,14) containing imidazole, the extremely high detergency and the metal anticorrosion prevention effect were shown. Further, it can be seen that the effect of preventing corrosion of metals is enhanced with respect to a composition (reference example) which is neutral but does not use the nitrogen-containing aromatic cyclic compound represented by the above general formula (I) (composition) Article 103-105, composition s11, s12 contrast reference).

DESCRIPTION OF SYMBOLS 10 Wafer 12 Al alloy film 14 Titanium nitride film 16 Wiring 18 Silicon oxide film 20 Via hole 24 Interlayer insulating film 26 Titanium nitride film 28 Titanium film 29 Recess 30 Al alloy film 32 Titanium nitride film 34 Wiring R Resist G Residue (plasma etching residue and Ashing residue)

Claims (20)

Water, a cleaning agent, a basic organic compound, an acidic organic compound, and a nitrogen-containing aromatic cyclic compound represented by the following general formula (I), and substantially adjusted to neutrality for semiconductors A cleaning composition for a substrate.

(Wherein R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ² , R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group, or Represents a benzyl group.)   The compound represented by the general formula (I) is imidazole, N-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, or 2-phenylimidazole. The cleaning composition according to claim 1.   The cleaning composition according to claim 2, wherein the compound represented by the general formula (I) is imidazole.   The cleaning composition according to claim 1, wherein the acidic organic compound is a monofunctional, difunctional, trifunctional, or tetrafunctional organic acid.   The acidic organic compound is lactic acid, citric acid, formic acid, oxalic acid, acetic acid, propionic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, glycolic acid, salicylic acid, tartaric acid, and malic acid. The cleaning composition according to claim 1, wherein the cleaning composition is at least one compound selected from the group consisting of:   The cleaning composition according to any one of claims 1 to 5, wherein the basic organic compound is at least one compound selected from the group consisting of an organic amine and a quaternary ammonium hydroxide. object.   The cleaning composition according to any one of claims 1 to 6, wherein the basic organic compound is an organic amine having no hydroxyl group.   The cleaning composition according to claim 1, wherein the basic organic compound is a tetraalkylammonium hydroxide.   The cleaning agent is at least one compound selected from the group consisting of hydroxylamine, hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine nitrate, and hydroxylamine phosphate. 9. The cleaning composition according to any one of 8 above.   Furthermore, the water-soluble organic solvent is contained, The cleaning composition of any one of Claims 1-9 characterized by the above-mentioned.   Furthermore, amino-group containing carboxylic acid is contained, The cleaning composition of any one of Claims 1-10 characterized by the above-mentioned.   The cleaning composition according to claim 11, wherein the amino group-containing carboxylic acid is histidine and / or arginine.   Furthermore, the cleaning composition of any one of Claims 1-12 containing 0.1 mass% or more and less than 0.5 mass% acidic inorganic compound with respect to the total mass of a cleaning composition.   The acidic inorganic compound is at least one compound selected from the group consisting of phosphoric acid, boric acid, hexafluorophosphoric acid, ammonium phosphate, ammonium borate, and ammonium hexafluorophosphate. The cleaning composition according to 1.   The cleaning composition according to claim 14, wherein the acidic inorganic compound is phosphoric acid and / or a salt thereof.   The cleaning composition according to any one of claims 1 to 15, which is particularly suitable as a cleaning liquid for removing plasma etching residue and / or ashing residue in a semiconductor element manufacturing process.   The cleaning composition according to claim 1, wherein the semiconductor substrate to be cleaned includes an exposed aluminum layer, a copper layer, or a titanium nitride layer.   A plasma etching residue and / or an ashing residue on a semiconductor substrate is cleaned with the cleaning composition according to claim 1.   The cleaning method according to claim 18, wherein the cleaning process is performed at a temperature of 50 to 90 ° C. (A) (a-1) an etching step of performing plasma etching on the semiconductor substrate, and / or (a-2) an ashing step of performing ashing on the resist on the semiconductor substrate, and
(B) The plasma etching residue and / or ashing residue formed on the semiconductor substrate in the etching step and / or the ashing step is cleaned and removed by the cleaning composition according to any one of claims 1 to 17. The manufacturing method of the semiconductor element characterized by including the washing | cleaning process to perform.

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