TW201430172A - Etching solution, etching method using the same and method for fabricating semiconductor device - Google Patents

Abstract

An etching solution is provided, which treats a substrate having a first layer containing TiN and a second layer containing at least one metal selected from transition metals from groups 3 to 11 to selectively remove the first layer, and contains an inorganic compound represented by the following formula (1), an oxidant and an anticorrosive to the second layer. Hal-Q...(1) Hal represents a halogen atom, and Q represents an atom or atomic group which becomes a monovalent cation.

Description

Etching liquid, etching method using the same, and manufacturing method of semiconductor element

The present invention relates to an etching liquid for a semiconductor substrate, an etching method using the same, and a method of manufacturing a semiconductor device.

The miniaturization and diversification of semiconductor elements are progressing, and the processing methods thereof are also diversified in various element structures or manufacturing steps. As for the etching of the substrate, development has been progressed in both dry etching and wet etching, and various chemical liquids or processing conditions have been proposed depending on the type or structure of the substrate material.

Among them, in the case of fabricating a component structure such as a complementary metal oxide semiconductor (CMOS) or a dynamic random access memory (DRAM), a technique of precisely etching a specific material is important as One of the corresponding techniques can be exemplified by wet etching using a chemical liquid. For example, in the production of a circuit wiring or a metal electrode material in a micro transistor circuit, or in the production of a substrate having a barrier layer or a hard mask, a precise etching process is required. However, for substrates having various metal compounds, suitable etching conditions or chemical solutions have not been fully studied. Research. In this case, a hard mask or the like which is applied to the element substrate is effectively removed, and a chemical solution for etching titanium nitride (TiN) is specifically studied (see Patent Literature). 1~ Patent Document 6).

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-257191

[Patent Document 2] International Publication No. 2012/048079

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2009-021516

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2005-097715

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2007-067367

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2008-547202

However, in recent semiconductor device manufacturing, it is required to form a metal hard mask (MHM) containing TiN in a state in which a contact plug including tungsten (W) or copper (Cu) is exposed. ) Processing techniques for wet etching. Therefore, it is necessary to remove the hard mask of the firm TiN without damaging the contact plug made of metal. That is, since a chemical liquid having only the removability of TiN has been developed, the demand cannot be satisfied. In particular, in recent years, contact plugs have become increasingly finer, and the slimness and selective etching difficulty of the chemical liquid has been further increased.

Accordingly, it is an object of the present invention to provide an etching solution for selectively and efficiently removing a first layer containing titanium nitride (TiN), an etching method using the same, and a semiconductor element with respect to a second layer containing a specific metal. Production method.

The above problems are solved by the following methods.

[1] An etching solution for treating a substrate having a first layer containing titanium nitride (TiN) and a second layer containing at least one metal selected from the group consisting of transition metals of Groups 3 to 11 The first layer is removed, and contains an inorganic compound represented by the following formula (1), an oxidizing agent, and an anticorrosive agent for the second layer: Hal-Q (1)

(Hal represents a halogen atom; Q represents an atom or a group of atoms which become a monovalent cation).

[2] The etching solution according to [1] above, wherein the second layer has copper (Cu) or tungsten (W).

[3] The etching solution according to the above [1] or [2] wherein the halogen atom is a fluorine atom, a chlorine atom, or a bromine atom.

[4] The etching solution according to any one of the above [1] to [3] wherein the inorganic compound is hydrochloric acid (HCl).

[5] The etching solution according to any one of [1] to [4] wherein the corrosion inhibitor is selected from the group consisting of a nitrogen-containing heteroaromatic compound, an oxygen-containing organic compound, an aromatic compound, a basic compound, an organic acid, A group consisting of an amine group-containing carboxylic acid compound, a surfactant, and a quaternary phosphonium compound.

[6] The etching solution according to any one of the above [1] to [5] wherein the corrosion inhibitor is represented by any one of the following formulas (A-1) to (A-3):

(R ⁶¹ represents an alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, or an aralkyl group having 7 to 40 carbon atoms; and R ⁶² to R ⁶⁹ each independently represent an alkyl group having 1 to 30 carbon atoms; An alkenyl group having 2 to 30 carbon atoms or an aralkyl group having 7 to 30 carbon atoms; X ^- is a relative anion; R ⁷⁰ is a substituent; and m1 is an integer of 0 to 5).

[7] The etching solution according to any one of the above [1] to [5] wherein the corrosion inhibitor comprises a compound represented by any one of the following formulas (I) to (IX):

(R ¹ to R ³⁰ each independently represent a hydrogen atom or a substituent; in this case, each adjacent R ¹ to R ³⁰ may be bonded or condensed to form a cyclic structure; A represents a hetero atom; wherein A is a divalent At the time, R ¹ , R ³ , R ⁶ , R ¹¹ , R ²⁴ and R ²⁸ ) which are substituted on A are not present.

[8] The etching solution according to any one of [1] to [5] wherein the corrosion inhibitor comprises a compound represented by the following formula (O-1): R ¹¹ -(-OR ¹³ -) _n - OR ¹² ...(O-1)

(R ¹¹ and R ¹² are each independently a hydrogen atom or an alkyl group having 1 or more and 25 or less carbon atoms; and R ¹³ is a linear or branched alkyl group having 1 or more and 4 or less carbon atoms; When R ¹³ , they may be different; n is an integer of 1 or more and 8 or less).

[9] The etching solution according to any one of [1] to [8] above which contains 0.01% by mass to 10% by mass of an anticorrosive agent.

[10] The etching solution according to any one of [1] to [9] wherein the oxidizing agent is hydrogen peroxide.

[11] The etching solution according to any one of the above [1] to [10] wherein the oxidizing agent is contained in an amount of 0.1% by mass to 30% by mass.

[12] The etching solution according to any one of the above [1] to [11] wherein the inorganic compound is contained in an amount of 0.01% by mass to 10% by mass.

[13] The etching solution according to any one of [1] to [12] wherein a ratio of an etching rate (R1) of the first layer to an etching rate (R2) of the second layer (R1/R2) ) is 2 or more.

[14] An etching method for treating a substrate having a first layer containing titanium nitride (TiN) and a second layer containing at least one metal selected from the group consisting of transition metals of Group 3 to Group 11 An etching solution containing an inorganic compound represented by the following formula (1), an oxidizing agent, and an anticorrosive agent for the second layer is applied to a substrate to perform selective removal of the first layer: Hal-Q... )

(Hal represents a halogen atom; Q represents an atom or a group of atoms which become a monovalent cation).

[15] The etching method according to [14] above, wherein the second layer has copper (Cu) or tungsten (W).

[16] The etching method according to [14] or [15], wherein the first liquid containing the oxidizing agent and the second liquid containing the inorganic compound and the corrosion inhibitor are separately prepared as an etching liquid, and the two are mixed. Apply to the substrate at the right time.

[17] A method of producing a semiconductor device, wherein the first layer containing titanium nitride (TiN) is removed by an etching method according to any one of [14] to [16], and is manufactured from the remaining substrate. Semiconductor component.

According to the etching liquid and the etching method of the present invention, and the method for producing a semiconductor device using the same, the first layer containing TiN can be selectively and efficiently removed with respect to the second layer containing a specific metal.

The above and other features and advantages of the invention will be apparent from the description and appended claims.

1‧‧‧TiN layer (1st floor)

2‧‧‧SiON layer (3rd layer (1))

3‧‧‧SiOC layer (3rd layer (2))

4‧‧‧Cu/W layer (layer 2)

5‧‧‧ pathway

10, 20‧‧‧ semiconductor substrate

11‧‧‧Reaction container

12‧‧‧Rotating table

13‧‧‧Spray outlet

14‧‧ ‧ Confluence

S‧‧‧Substrate

A, B‧‧‧ liquid

d‧‧‧Exposed width

Fc, fd‧‧‧ flow path

M‧‧‧Rotary Drive Department

R‧‧‧ direction

t‧‧‧Mobile track

1 is a cross-sectional view schematically showing an example of a manufacturing process (before etching) of a semiconductor substrate according to an embodiment of the present invention.

2 is a cross-sectional view schematically showing an example of a manufacturing process (after etching) of a semiconductor substrate according to an embodiment of the present invention.

Fig. 3 is a view showing a configuration of a part of a wet etching apparatus according to a preferred embodiment of the present invention.

Fig. 4 is a plan view schematically showing a movement trajectory of a nozzle with respect to a semiconductor substrate according to an embodiment of the present invention.

First, a preferred embodiment of the etching step of the etching method of the present invention will be described with reference to Figs. 1 and 2 .

[etching step]

FIG. 1 is a view showing a semiconductor substrate before etching. In the manufacturing example of the present embodiment, the SiOC layer 3 and the SiON layer 2 which are specific third layers are disposed on a germanium wafer (not shown), and the TiN layer 1 is formed on the upper side. At this time, the composite layer has formed a via 5, and a second layer (metal layer) 4 containing a metal is formed at the bottom of the via 5. The etching liquid (not shown) of this embodiment is applied to the substrate 10 in this state, and the TiN layer is removed. As a result, as shown in FIG. 2, the state in which the TiN film was removed can be obtained. Substrate 20. In the present invention or a preferred embodiment thereof, the etching as illustrated is preferable, but the residual of the TiN layer or the slight corrosion of the second layer is appropriately allowed depending on the required quality of the semiconductor element to be produced or the like. The invention is not to be construed as being limited by the description.

In addition, when it is called a germanium substrate or a semiconductor substrate, or simply a substrate, it is used not only in the meaning of a germanium wafer but also in the meaning of including a substrate structure in which a circuit structure is implemented. The member of the substrate refers to a member constituting the above-described ruthenium substrate, and may include one type of material or a plurality of materials. The processed semiconductor substrate is sometimes referred to as a semiconductor substrate article. A wafer and a processed product thereof which are further subjected to processing and cutting as needed are referred to as a semiconductor element or a semiconductor device. The direction of the substrate will be referred to as "upper" or "day" on the opposite side (TiN side) and "on the wafer side" (SiOC side) as shown in Fig. 1 unless otherwise specified. Or "bottom."

[etching solution]

Next, a preferred embodiment of the etching liquid of the present invention will be described. The etching solution of the present embodiment contains an inorganic compound represented by the formula (1) (hereinafter sometimes referred to as "specific inorganic compound"), an oxidizing agent, and an anticorrosive agent for the second layer. Hereinafter, each component will be described, and each component will be described.

(oxidant)

Examples of the oxidizing agent include nitric acid, hydrogen peroxide, ammonium persulfate, perboric acid, peracetic acid, periodic acid, perchloric acid, or a combination thereof, and among them, nitric acid and hydrogen peroxide are particularly preferable.

The oxidizing agent is preferably contained in an amount of 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 2% by mass or more, based on the total mass of the etching liquid of the present embodiment. The upper limit of the oxidizing agent content is preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 15% by mass or less, and particularly preferably 10% by mass or less. When the oxidizing agent content is at most the above upper limit value, it is preferable from the viewpoint of obtaining good protective properties (etching selectivity) of the second layer. By setting the oxidizing agent content to the above lower limit value or more, a sufficient etching rate of the first layer can be secured, which is preferable.

In addition, oxalic acid is a reducing agent and is not included in the oxidizing agent. In particular, when oxalic acid is used in the etching of the present invention, excessive etching property to the metal layer is exhibited due to conditions and the like, and good selectivity cannot be obtained.

These oxidizing agents may be used alone or in combination of two or more.

(specific inorganic compound)

The specific inorganic compound is represented by the following formula (1).

Hal-Q...(1)

(Hal represents a halogen atom. Q represents an atom or a group of atoms which become a monovalent cation.)

Examples of the halogen atom (Hal) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, a fluorine atom and a chlorine atom are preferred. Q is not particularly limited, and examples thereof include a hydrogen atom. Specific examples of the specific inorganic compound include hydrochloric acid (HCl) or a salt thereof or hydrofluoric acid (HF) or a salt thereof.

The content of the specific inorganic compound is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and particularly preferably 0.5% by mass or more. The upper limit of the content of the specific inorganic compound is preferably 10% by mass or less, more preferably 7% by mass or less, and particularly preferably 5% by mass or less. It is preferable from the viewpoint that the content of the specific inorganic compound is not more than the above upper limit value and the selection ratio of the etching rate is optimized. By setting the content of the specific inorganic compound to the above lower limit value or more, a sufficient TiN etching rate can be obtained, which is preferable.

The relationship with the oxidizing agent is preferably 1 part by mass or more of the specific inorganic compound, and more preferably 10 parts by mass or more, based on 100 parts by mass of the oxidizing agent. The upper limit of the specific inorganic compound is preferably 1000 parts by mass or less, more preferably 500 parts by mass or less, and particularly preferably 300 parts by mass or less. By using the amounts of both in an appropriate relationship, as described above, good etching properties can be achieved, and high etching selectivity is achieved at the same time.

The specific inorganic compound may be used singly or in combination of two or more.

(corrosion inhibitor)

(nitrogen-containing heteroaromatic compounds)

As the corrosion inhibitor, a nitrogen-containing heteroaromatic compound can be used. The nitrogen-containing heteroaromatic compound is preferably an imidazole compound, a pyrazole compound, a triazole compound, a tetrazole compound, a pyridine compound or a quinoline compound. These nitrogen-containing heteroaromatic compounds may have any substituent (for example, a substituent T described later).

The nitrogen-containing heteroaromatic compound is preferably a heteroaromatic ring compound having two or more nitrogen atoms in the molecule and having a condensed ring structure, and more preferably intramolecular. A heteroaromatic ring compound having three or more nitrogen atoms and having a condensed ring structure. Here, "two or more nitrogen atoms" or "three or more nitrogen atoms" is preferably an atom constituting a condensed ring, and as such a heteroaromatic ring compound, an imidazole compound, a triazole compound or a tetrazole compound is preferable.

Specific examples of the nitrogen-containing heteroaromatic compound are more preferably selected from the group consisting of imidazole, benzimidazole, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1-[N, N-bis(hydroxyethyl)aminoethyl]benzotriazole, 1-(1,2-dicarboxyethyl)benzotriazole, tolyltriazole, tetrazole, 5-aminotetrazole or 1H-tetrazoliumpentaacetic acid. These exemplified compounds may have a substituent T as described above.

(aromatic compound)

As the corrosion inhibitor, an aromatic compound can also be preferably used. The aromatic compound described above will be described in detail in the following formula (VII).

(oxygenated organic compounds)

As the corrosion inhibitor, it is also preferred to use an oxygen-containing organic compound. The oxygen-containing organic compound is preferably an ether compound or an alcohol compound to be described later, and more details are described in the description of the following formula (O-1).

(alkaline compound)

As the corrosion inhibitor, it is also preferred to use an alkaline organic compound. The organic amine used as the basic organic compound includes monoalkanolamines such as monoethanolamine, diethanolamine, triethanolamine, diethylene glycolamine, N-hydroxyethylpiperazine, and/or ethylamine, benzylamine, and Ethylamine, n-butylamine, 3-methoxypropylamine, tert-butylamine, n-hexylamine, cyclohexylamine, n-octylamine, 2-ethylhexylamine, o-xylenediamine, Meta-xylene diamine, 1-methylbutylamine, ethylenediamine (EDA), 1,3-propanediamine, 2-aminobenzylamine, N-benzylethylenediamine, diethylenetriamine, triethylenetetramine, etc. An organic amine having a hydroxyl group.

(four-level bismuth compound)

As the corrosion inhibitor, it is also preferred to use a quaternary phosphonium compound. Among them, it is preferred to use a quaternary organic ruthenium compound, more preferably a quaternary ammonium hydroxide. As a specific example, a tetraalkylammonium hydroxide is preferable, and a tetraalkylammonium hydroxide substituted with a lower (carbon number of 1-4) alkyl group is more preferable, and specifically, tetramethyl group is mentioned. Ammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), and the like. Further, examples of the quaternary ammonium hydroxide include trimethylhydroxyethylammonium hydroxide (choline), methyltris(hydroxyethyl)ammonium hydroxide, and tetrakis(hydroxyethyl)ammonium hydroxide. Benzyltrimethylammonium hydroxide (BTMAH) and the like. Further, a combination of an ammonium hydroxide and one or more quaternary ammonium hydroxides may also be used. Among these, TMAH, TEAH, TPAH, TBAH, and choline are preferred, and TMAH and TBAH are particularly preferred.

These organic amines and quaternary ammonium hydroxides may be used alone or in combination of two or more.

Further, it is also preferred to use a pyridinium compound or an anthracene compound, and these will be described in detail in the following formulas (A-1) to (A-3).

(organic acid)

As the corrosion inhibitor, it is also preferred to use an organic acid. In order to effectively prevent corrosion of metals such as tungsten, copper, and these alloys, a carboxylic acid is preferred among organic acids, and a hydroxycarboxylic acid having a hydroxyl group is particularly effective for preventing metal corrosion, and thus is more preferable. Carboxylic acid for these metals Has a chelation effect. Preferred carboxylic acids include: monocarboxylic acids and polycarboxylic acids. The carboxylic acid is not limited to these, and examples thereof include formic acid, acetic acid, propionic acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, and antibutene. Acid, phthalic acid, 1,2,3-benzenetricarboxylic acid, glycolic acid, lactic acid, citric acid, salicylic acid, tartaric acid, gluconic acid, glycolic acid, malic acid, acetohydroxamic acid , benzoxamic acid, salicylic acid, phthalic acid, benzoic acid, dihydroxybenzoic acid and mixtures of these. Among them, citric acid, malic acid, tartaric acid, glycolic acid, gluconic acid, and lactic acid which are hydroxycarboxylic acids can be preferably used.

(Amino group-containing carboxylic acid compound)

As the corrosion inhibitor, it is also preferred to use a carboxylic acid compound containing an amine group. Examples of the carboxylic acid having an amine group include glycine, alanine, aspartame, aspartic acid, arginine, glutamine, and bran. Amino acid such as glutamic acid, histidine, serine, cysteine, tyrosine, phenylalanine; and/or an amine polycarboxylate group containing the following components {B Diamine tetraacetate (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylethylenediamine triacetate (HEDTA), dihydroxyethylethylenediaminetetraacetate (DHEDDA), nitrogen triacetic acid Salt (NTA), hydroxyethyliminodiacetic acid salt (HIDA), β-alanine diacetate, aspartic acid diacetate, methylglycine diacetate, iminodisuccinate , a serine diacetate, a hydroxyiminodisuccinate, a dihydroxyethylglycinate, an aspartate, a glutamate, etc.; a hydroxycarboxylate group comprising the following components { a glycolate, a tartrate, a citrate, a gluconate, etc.; a cyclic carboxylate group comprising the following components: a pyromellitic acid salt, a benzopolycarboxylate, a cyclopentane tetracarboxylate, etc.; an ether carboxylate group comprising the following components: {carboxymethylhydroxymalonate, carboxymethyloxysuccinate, oxydisuccinate , tartaric acid monosuccinate, tartaric acid disuccinate, etc.; other carboxylate groups including the following components {maleic acid derivative, oxalate, etc.); organic carboxylic acid (salt) containing the following components Polymer group {acrylic polymer and copolymer (acrylic acid-allyl alcohol ester copolymer, acrylic acid-maleic acid copolymer, hydroxy acrylic acid polymer, polysaccharide-acrylic acid copolymer, etc.); containing the following components Polycarboxylic acid polymer and copolymer group {maleic acid, itaconic acid, fumaric acid, tetramethylene-1,2-dicarboxylic acid, succinic acid, aspartic acid, glutamic acid a polymer and a copolymer of a monomer; a glyoxylic acid polymer having the following components, a polysaccharide group {starch, cellulose, amylose, pectin, carboxymethylcellulose, etc.); Phosphonate group of the following components {methyl diphosphonate, aminotrimethylene phosphonate, ethylene diphosphonate, 1 -hydroxyethylidene-1,1-diphosphonate, ethylaminobismethylenephosphonate, ethylenediamine bismethylenephosphonate, ethylenediaminetetramethylenephosphonate, six Methylene diamine tetramethylene phosphonic acid, propylene diamine tetramethylene phosphonate, diethylene triamine penta methylene phosphonate, triethylene tetraamine hexamethylene phosphonate and tetraethylene Amine hexamethylene phosphonate, etc.}.

(surfactant)

As the corrosion inhibitor, it is also preferred to use a surfactant. As the surfactant, a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used.

Examples of the nonionic surfactant include a polyalkylene oxide alkyl phenyl ether surfactant, a polyalkylene oxide ether surfactant, and polyethylene oxide. A block polymer-based surfactant of polypropylene oxide, a polyoxyalkylene distyrenated phenyl ether surfactant, a polyalkylene tribenzyl phenyl ether surfactant, an acetylene polyalkylene oxide system Surfactant.

Examples of the anionic surfactant include alkyl sulfate, alkyl sulfonic acid, alkyl benzene sulfonic acid, alkyl naphthalene sulfonic acid, alkyl diphenyl ether sulfonic acid, and polyoxyalkylene ether carboxylic acid. Polyoxyethylene ethyl ether ether acetate, polyoxyethylene ethyl ether ether propionic acid, and salts thereof.

Examples of the cationic surfactant include a quaternary ammonium salt-based surfactant or an alkylpyridine-based surfactant.

Examples of the amphoteric surfactant include a betaine type surfactant, an amino acid type surfactant, an imidazoline type surfactant, and an amine oxide type surfactant.

Hereinafter, a preferred example of the corrosion inhibitor is described in the general formula. The corrosion inhibitor is preferably a compound represented by any one of the following formulas (I) to (IX).

. R ¹ ~R ³⁰

In the formula, R ¹ to R ³⁰ each independently represent a hydrogen atom or a substituent. The substituent is exemplified by an alkyl group (preferably having a carbon number of 1 to 20, more preferably 1 to 12, particularly preferably 1 to 6, particularly preferably 1 to 3) or an alkenyl group (preferably having a carbon number). 2~20, more preferably 2~12, especially good 2~6, especially good 2~3), aryl (preferably carbon number 6~24, better 6~14, especially good 6~) 10) a heterocyclic group (preferably having a carbon number of 1 to 20, more preferably 2 to 12, particularly preferably 2 to 6), an alkoxy group (preferably having a carbon number of 1 to 20, more preferably 1 to 12) , especially good for 1~6, especially good for 1~3), sulfhydryl (preferably carbon number 2~20, better 2~12, especially good 2~6, especially good 2~3), Amine group (preferably having a carbon number of 0 to 6, more preferably 0 to 4, and particularly preferably 0 to 2), a carboxyl group, a phosphate group, a hydroxyl group, a thiol group (-SH), or a boric acid group (-B(OH). ₂ ) Wait. Further, the aryl group is preferably a phenyl group or a naphthyl group. The above heterocyclic group may, for example, be a nitrogen-containing heteroaromatic group, preferably a 5-membered nitrogen-containing heteroaromatic group, more preferably a pyrrolyl group, an imidazolyl group, a pyrazolyl group, a triazolyl group or a tetrazole. base. These substituents may further have a substituent within the range in which the effects of the present invention are exerted. Further, in the above substituent, an amine group, a carboxyl group, a phosphoric acid group or a boric acid group may form a salt thereof. Examples of the counter ion forming a salt include a quaternary ammonium such as an ammonium ion (NH ₄ ⁺ ) or a tetramethylammonium ion ((CH ₃ ) ₄ N ⁺ ).

The above substituent may be substituted via any linking group. Examples of the linking group include an alkylene group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms), and an alkenyl group (preferably Carbon number 2 to 20, more preferably 2 to 12, especially preferably 2 to 6, particularly preferably 2 to 3), ether group (-O-), imine group (preferably carbon number 0 to 4, more Preferably, it is 0 to 2), a thioether group (-S-), a carbonyl group, or a combination of these. Hereinafter, the linking group will be referred to as a linking group L. In addition, the linking group exerts the effects of the present invention. Further, a substituent may be further included in the range.

Among them, R ¹ to R ^{30 are} preferably an alkyl group having 1 to 6 carbon atoms, a carboxyl group, an amine group (preferably having a carbon number of 0 to 4), a hydroxyl group, or a boronic acid group. These substituents can be substituted via the linking group L as described above.

Further, the adjacent members of R ¹ to R ³⁰ may be linked or condensed to each other to form a ring structure. Examples of the ring structure to be formed include a pyrrole ring structure, an imidazole ring structure, a pyrazole ring structure, and a triazole ring structure. Further, these ring moieties may further have a substituent within the range in which the effects of the present invention are exerted. Further, when the ring structure formed here is a benzene ring, it is classified into the formula (VII) for finishing.

. A

A represents a hetero atom and represents a nitrogen atom, an oxygen atom, a sulfur atom, or a phosphorus atom. However, when A is a divalent (oxygen atom or a sulfur atom), R ¹ , R ³ , R ⁶ , R ¹¹ , R ²⁴ and R ^{28 are not present} .

The compound represented by the above formula (VII) is preferably one represented by the following formula (VII-1) to formula (VII-5).

[Chemical 4]

R ^a represents an acidic group, preferably a carboxyl group, a phosphoric acid group, or a boronic acid group. The above acidic group may be substituted via the above-mentioned linking group L.

R ^b is an alkyl group (preferably having a carbon number of 1 to 12, more preferably a carbon number of 1 to 6), an amine group (preferably having a carbon number of 0 to 4), a hydroxyl group or an alkoxy group (preferably having a carbon number of 1). ~6), or sulfhydryl (preferably carbon number 1~6). The above substituent R ^b may be substituted via the above-mentioned linking group L. When a plurality of R ^b are present, these may be linked or condensed to form a ring structure.

N1 is an integer from 1 to 5. N2 is an integer from 0 to 5. N3 is an integer from 0 to 4. N4 represents an integer from 1 to 4. N5 represents an integer from 0 to 7. When n1 to n5 are each 2 or more, the plurality of substituents defined herein may be the same or different.

Wherein A is synonymous with A as defined above. R ^c , R ^d , and R ^e are groups synonymous with R ¹ to R ³⁰ . Wherein, when A is divalent, R ^c and R ^e are absent.

Hereinafter, examples of the compound represented by any one of the above formulas (I) to (IX) may be mentioned, but the invention is not limited thereto.

Further, the following exemplary compounds include an example of a tautomer, and other tautomers are also included in the preferred examples of the present invention. This is for the above The same applies to the formulas (I) to (IX) and (VII-1) to (VII-5).

The above-mentioned corrosion inhibitor is also preferably any of the following formulas (A-1) to (A-3). As shown in the formula.

. R ⁶¹

R ⁶¹ represents an alkyl group having 1 to 40 carbon atoms (preferably having 1 to 20 carbon atoms), an alkenyl group having 2 to 40 carbon atoms (preferably having 2 to 20 carbon atoms), or an aralkyl having 7 to 40 carbon atoms. Base (preferably carbon number 7 to 23, more preferably 7 to 15). Further, R ^{61 is} preferably an alkyl group having 5 to 30 carbon atoms, an alkenyl group having 5 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms. The alkyl or alkenyl group may further have a substituent T.

. R ⁶² ~R ⁶⁹

R ⁶² to R ⁶⁹ each independently represent an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, or an aralkyl group having 7 to 30 carbon atoms. Further, R ⁶² to R ⁶⁹ are each independently preferably an alkyl group having 1 to 25 carbon atoms, an alkenyl group having 2 to 25 carbon atoms, or an aralkyl group having 7 to 25 carbon atoms, more preferably 1 to 20 carbon atoms. An alkyl group, an alkenyl group having 2 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms.

When R ⁶¹ to R ⁶⁹ contain an alkyl group or an alkenyl group, the substituent T may be further added. In addition, it may be a linear one, a brancher, or a ring. R ⁶² to R ⁶⁹ are connected to each other to form a ring.

. X ^-

X ^- is a relative anion. Preferred are hydroxide ions, nitrate ions, or halide ions (preferably chloride ions or bromide ions).

. R ⁷⁰

R ⁷⁰ is a substituent. Examples of the substituent include a substituent T to be described later. Among them, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aralkyl group having 7 to 25 carbon atoms is preferable.

. M1

M1 is an integer from 0 to 5.

The above-mentioned corrosion inhibitor is also preferably a compound represented by the following formula (O-1).

R ¹¹ -(-OR ¹³ -) _n -OR ¹² ...(O-1)

. R ¹¹ , R ¹²

R ¹¹ and R ¹² each independently represent a hydrogen atom or an alkyl group having 1 or more and 25 or less carbon atoms. Among these, an alkyl group having 3 or more and 20 or less carbon atoms is preferable, and an alkyl group having 5 or more and 15 or less carbon atoms is more preferable.

. R ¹³

R ¹³ is a linear or branched alkylene chain having 1 or more and 4 or less carbon atoms. When there are a plurality of R ¹³ , they may be different, respectively.

. n

n is an integer of 1 or more and 8 or less.

The content of the corrosion inhibitor is not particularly limited, and is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and particularly preferably 0.1% by mass or more in the etching liquid. The upper limit of the content of the corrosion inhibitor is not particularly limited, but is preferably 15% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less. By setting the content of the anticorrosive agent to the above lower limit value or more, a preferable protective effect against the metal layer can be obtained, which is preferable. On the other hand, from the viewpoint of not impeding good etching performance, it is preferred to set the content of the anticorrosive agent to be equal to or less than the above upper limit value.

The above-mentioned corrosion inhibitors may be used alone or in combination of two or more.

In the present invention, the reason why the above-mentioned corrosion inhibitor contributes to good etching selectivity has not been determined, but it is presumed as follows. First of all, it can be understood that the oxidizing agent oxidizes titanium nitride to facilitate its dissolution. On the other hand, it is considered that a gas is generated from a specific inorganic compound that coexists, and further functions as an oxidizing agent to achieve better etchability of titanium nitride (first layer). That is, it is estimated that the oxidizing agent and the specific inorganic compound act synergistically to exhibit good removability of the titanium nitride film (first layer). At the same time, it can be understood that the above-mentioned corrosion inhibitor forms a complex compound adsorbed on the surface of the metal layer (the second layer) to suppress the dissolution of the metal layer. On the other hand, it is speculated that it is also adsorbed to the surface by hydrophobic interaction, and the dissolution of the metal layer is also suppressed by such a mechanism.

Further, in the present specification, the expression of the compound (for example, when it is referred to as a compound at the end) is used in addition to the compound itself, in the meaning of including a salt thereof and an ion thereof. In addition, it means a derivative which changes a part of a substituent, etc., in the range which exhibits a desired effect.

In the present specification, a substituent which is unsubstituted and unsubstituted, which is the same as the linking group, means that any substituent may be present on the group. This is also synonymous for compounds that are not explicitly substituted or unsubstituted. As a preferable substituent, the following substituent T is mentioned.

The substituent T can be exemplified below.

Is an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2 - ethoxyethyl, 1-carboxymethyl, etc.), alkenyl (preferably an alkenyl group having 2 to 20 carbon atoms, such as a vinyl group, an allyl group, an oleyl group, etc.), an alkynyl group (preferably Alkynyl group having 2 to 20 carbon atoms, such as ethynyl, butadiynyl, phenylethynyl, etc., cycloalkyl (preferably a cycloalkyl group having 3 to 20 carbon atoms, such as cyclopropyl group, Cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), aryl (preferably an aryl group having 6 to 26 carbon atoms, such as phenyl, 1-naphthyl, 4-methoxyphenyl, 2 - chlorophenyl, 3-methylphenyl, etc.), heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, preferably 5 members having at least one oxygen atom, sulfur atom, and nitrogen atom) a heterocyclic group of a ring or a 6-membered ring, such as 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2-oxazolyl, etc., alkoxy ( It is preferably an alkoxy group having 1 to 20 carbon atoms, such as a methoxy group, an ethoxy group, an isopropoxy group or a benzyloxy group, or an aryloxy group (preferably having 6 to 6 carbon atoms). An aryloxy group of 26, such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms) Alkoxycarbonyl group, such as ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc.), amine group (preferably an amine group having 0 to 20 carbon atoms, including an alkylamino group, an arylamine group, For example, amine group, N,N-dimethylamino group, N,N-diethyl Amine group, N-ethylamino group, anilino group, etc.), amidoxime group (preferably a sulfonylamino group having 0 to 20 carbon atoms, such as N,N-dimethylaminesulfonyl, N - phenylamine sulfonyl group, etc., fluorenyl group (preferably a fluorenyl group having 1 to 20 carbon atoms, such as an ethyl group, a propyl group, a butyl group, a benzhydryl group, etc.), a decyloxy group (preferably) It is a fluorenyloxy group having 1 to 20 carbon atoms, such as an ethoxylated group or a benzhydryloxy group, and an aminomethyl sulfonyl group (preferably an aminocarbenyl group having 1 to 20 carbon atoms, such as N, N). - dimethylamine-methyl group, N-phenylamine-methyl group, etc.), guanamine group (preferably a guanamine group having 1 to 20 carbon atoms, such as an acetamino group, a benzylamino group, etc.) a sulfonamide group (preferably an amine sulfonyl group having 0 to 20 carbon atoms, such as methotrexate, benzenesulfonamide, N-methylformamide, N-ethylbenzenesulfonamide) And the like, an alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, such as a methylthio group, an ethylthio group, an isopropylthio group, a benzylthio group, etc.), an arylthio group (preferably a carbon atom) a number of 6 to 26 arylthio groups, such as phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc., alkylsulfonyl or arylsulfonyl (preferably carbon An alkylsulfonyl or arylsulfonyl group having a number of 1 to 20, such as a methylsulfonyl group, an ethylsulfonyl group, a benzenesulfonyl group, a hydroxyl group, a cyano group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like), more preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an amine group, a decylamino group, a hydroxyl group or a halogen. The atom is particularly preferably an alkyl group, an alkenyl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amine group, a decylamino group or a hydroxyl group.

Further, the substituent T may be further substituted on each of the groups listed in the substituent T.

In the compound or substituent, the linking group and the like contains an alkyl group. Alkyl, alkenyl. When alkenyl groups are extended, these may be cyclic or chain-like, and may be linear or may be The branch may be substituted as described above or may be unsubstituted. Further, when an aryl group, a heterocyclic group or the like is contained, these may be a single ring or a condensed ring, and may be substituted or unsubstituted.

In the present specification, the selection range of the substituent or the linking group of the compound is started, and each technical item such as temperature and thickness may be combined with each other even if the list is independently described.

(aqueous medium)

In the etching liquid of the present invention, water (aqueous medium) is preferably used as the medium, and it is preferred that each of the components contains an aqueous solution in which the components are uniformly dissolved. The content of water is preferably 50% by mass to 99.5% by mass, and preferably 55% by mass to 95% by mass based on the total mass of the etching liquid. In this case, a composition containing water as a main component (50% by mass or more) is particularly preferably referred to as a water-based composition, and is inexpensive compared with a composition having a high ratio of an organic solvent, and is suitable for an environment. From this point of view, the etching liquid of the present invention is preferably a water-based composition. The water (aqueous medium) may be an aqueous medium containing a dissolved component in a range that does not impair the effects of the present invention, or may contain an unavoidable minute mixed component. Among them, water subjected to purification treatment such as distilled water, ion-exchanged water, or ultrapure water is preferred, and ultrapure water used in semiconductor manufacturing is particularly preferably used.

(pH)

In the present invention, it is preferred to adjust the pH of the etching solution to -1 or more, and more preferably to 0 or more. The upper limit of the pH is preferably set to a pH of 5 or less, more preferably 4 or less, and still more preferably 3 or less. By setting the pH to be equal to or higher than the above lower limit value, It is preferable from the viewpoint that not only the etching rate of TiN can be made practical, but also the in-plane uniformity can be further improved. On the other hand, by setting the pH to be equal to or lower than the above upper limit, it is preferable to have corrosion resistance to other substrates such as SiO or SiOC. Further, in the present invention, the pH depends on the apparatus and conditions measured in the examples unless otherwise specified.

(other ingredients)

. pH adjuster

In the present embodiment, it is preferable to set the pH of the etching liquid to the above range, and to use a pH adjusting agent for the adjustment. As the pH adjuster, in order to increase the pH, a tetra-ammonium salt such as tetramethylammonium or choline, an alkali hydroxide or an alkaline earth salt such as potassium hydroxide, or an amine such as 2-aminoethanol or hydrazine is preferably used. Base compound. In order to lower the pH, a mineral acid such as hydrochloric acid, nitric acid, sulfuric acid or phosphoric acid, or formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid or 3,3-dimethyl group may be mentioned. Butyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, water Organic acids such as acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, tartaric acid, citric acid, lactic acid and the like.

The amount of the pH adjuster used is not particularly limited, and in order to adjust the pH to the above range, a necessary amount may be used.

These pH adjusting agents may be used alone or in combination of two or more.

(water soluble organic solvent)

In the etching solution of the present invention, a water-soluble organic solvent can be further added. Water soluble The organic solvent is preferably an organic solvent which can be mixed with water in an arbitrary ratio. Thereby, it is possible to further improve the uniform etching property in the plane of the wafer, and it is effective.

Examples of the water-soluble organic solvent include methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, ethylene glycol, propylene glycol, glycerin, 1,6-hexanediol, cyclohexanediol, and sorbose. Alcohol, xylitol, 2-methyl-2,4-pentanediol, 1,3-butanediol, 1,4-butanediol and other alcohol compound solvents, including alkylene glycol alkyl ethers (Ethylene Alcohol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol, dipropylene glycol, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol, polyethylene glycol, propylene glycol monomethyl ether, dipropylene glycol An ether compound solvent of monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether, or the like.

Among these, an alcohol compound solvent having a carbon number of 2 to 15 and an alcohol ether compound solvent having a carbon number of 2 to 15, more preferably an alcohol compound solvent having a hydroxyl group of 2 to 10 and having a carbon number of 2~ A hydroxyl group-containing ether compound solvent having a hydroxyl group. Particularly preferred is an alkylene glycol alkyl ether having a carbon number of 3-8. The water-soluble organic solvent may be used singly or in combination of two or more kinds as appropriate. Further, in the present specification, a compound having a hydroxyl group (-OH) and an ether group (-O-) in the molecule is included in principle in an ether compound (not referred to as an alcohol compound), particularly in the case of distinguishing between having a hydroxyl group and an ether group. In the case of these two compounds, they are sometimes referred to as ether compounds containing a hydroxyl group.

Among them, propylene glycol and dipropylene glycol are particularly preferred. The amount of the water-soluble organic solvent added is preferably from 0.1% by mass to 70% by mass, and more preferably from 10% by mass to 50% by mass based on the total amount of the etching liquid. When the amount is at least the above lower limit value, the uniformity of the above etching can be effectively improved.

The water-soluble organic solvent is preferably a compound represented by the following formula (O-2). Things.

R ²¹ -(-OR ²³ -) _m2 -OR ²² ...(O-2)

. R ²¹ , R ²²

R ²¹ and R ²² are each independently a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms. Among these, an alkyl group having 1 or more and 5 or less carbon atoms is preferable, and an alkyl group having 1 or more and 3 or less carbon atoms is more preferable.

. R ²³

R ²³ is a linear or branched alkylene chain having 1 or more and 4 or less carbon atoms. When a plurality of R ¹³ are stored, they may be different.

. M2

M2 is an integer of 1 or more and 6 or less.

The water-soluble organic solvent may be used singly or in combination of two or more.

(set)

The etching liquid of the present invention can be made into a kit in which the raw material is divided into a plurality of parts. For example, a solution composition containing the specific inorganic compound in an aqueous medium is prepared as a first liquid, and a solution composition containing the oxidizing agent in an aqueous medium is prepared as a second liquid. As an example of use, it is preferred to mix the two liquids to adjust the liquid etching solution, and then apply it to the etching treatment as appropriate. The corrosion inhibitor may be contained in any solution, preferably contained in the first liquid. By implementing in this way, it will not The deterioration of the liquid properties due to the decomposition of the oxidizing agent (for example, hydrogen peroxide) is caused, and the desired etching action can be effectively exerted. Here, the "timely" after mixing means a period until the desired effect is lost after mixing, and specifically, it is preferably within 60 minutes, more preferably within 30 minutes, and particularly preferably within 10 minutes. The lower limit does not exist in particular, and is actually more than 0 seconds. The corrosion inhibitor may be contained in the first liquid, or may be contained in the second liquid, and may be contained in the third liquid to be described later. Among them, it is preferred to contain an anticorrosive agent in a solution other than the second liquid (solution containing an oxidizing agent).

The concentration of the specific inorganic compound in the first liquid is not particularly limited, but is preferably 0.5% by mass or more, and more preferably 1.5% by mass or more. The upper limit of the concentration of the specific inorganic compound is preferably 20% by mass or less, and more preferably 10% by mass or less. By setting the concentration to the above range, it is preferable to be in a state suitable for mixing with the second liquid, and it is preferable to form a preferable concentration region of the etching liquid.

The concentration of the oxidizing agent in the second liquid is not particularly limited, but is preferably 0.1% by mass or more, and more preferably 0.5% by mass or more. The upper limit of the concentration of the oxidizing agent is preferably 20% by mass or less, preferably 10% by mass or less. By setting the concentration to the above range, it is preferable to be in a state suitable for mixing with the first liquid, and it is preferable to form a preferable concentration region of the etching liquid.

When the water-soluble organic solvent is used, it is preferably added to the first liquid side in advance. Alternatively, a solution composition containing a water-soluble organic solvent in an aqueous medium may be prepared and mixed as the third liquid with the first liquid and the second liquid.

The method of mixing the first liquid and the second liquid is not particularly limited, and it is preferred that the first liquid and the second liquid flow along the respective channels, so that the two are merged at the junction and mixed. Hehe. Then, it is preferable to further flow the flow path, and to eject or eject the etched liquid obtained from the discharge port to be in contact with the semiconductor substrate. In this embodiment, it is preferable to carry out the process from the joining of the joining points to the contact with the semiconductor substrate in the above-mentioned "timely" manner. As will be described using FIG. 3, the prepared etching liquid is ejected from the ejection port 13 and applied to the upper surface of the semiconductor substrate S in the reaction container 11. In the embodiment shown in FIG. 3, the two liquids A and B are supplied, merged at the joining point 14, and then transferred to the discharge port 13 via the flow path fc. The flow path fd represents a return path for recycling the medical liquid. Preferably, the semiconductor substrate S is located on the turntable 12, and is rotated together with the turntable by the rotary drive portion M. Further, the embodiment using such a substrate rotary device can be similarly applied to a treatment using an etching liquid which is not formed into a jacket.

(container)

The etching liquid of the present invention can be filled in an arbitrary container for storage, transportation, and use as long as it is not problematic (whether or not it is a set). Further, in the case of semiconductor-oriented applications, it is preferred that the container has a high degree of cleanliness and a small amount of elution of impurities. Examples of the container that can be used include "CLEAN BOTTLE" series manufactured by AICELLO CHEMICAL Co., Ltd., "Pure Bottle" manufactured by KODAMA PLASTICS Co., Ltd., etc., but are not limited thereto. For these.

[etching conditions]

The conditions for etching in the present embodiment are not particularly limited, and may be one-chip (spray type) etching or immersion type (batch type) etching. Spray etching In this case, the semiconductor substrate is transferred or rotated in a specific direction, and an etching liquid is ejected in the space to bring the etching liquid into contact with the semiconductor substrate. On the other hand, in the batch etching, the semiconductor substrate is immersed in a liquid bath containing an etching liquid, and the semiconductor substrate is brought into contact with the etching liquid in the liquid bath. These etching methods may be used as appropriate depending on the structure or material of the element.

In the temperature measuring method shown in the examples to be described later, the ambient temperature for etching is preferably 40 ° C or higher, more preferably 50 ° C or higher, and particularly preferably 55 ° C or higher. The upper limit of the ambient temperature is preferably 80 ° C or lower, more preferably 70 ° C or lower. By setting the ambient temperature to the above lower limit value or more, a sufficient etching rate for the TiN layer can be secured, which is preferable. It is preferable to set the ambient temperature to be equal to or lower than the above upper limit value to maintain the temporal stability of the etching treatment rate. The supply rate of the etching liquid is not particularly limited, but is preferably 0.05 L/min to 2 L/min, and more preferably 0.05 L/min to 1 L/min. When the flow rate is set to be low, the supply speed is preferably set to 0.1 L/min to 0.5 L/min. By setting the supply speed to the above lower limit value or more, it is possible to better ensure the uniformity in the in-plane of the etching, which is preferable. It is preferable to set the supply rate to be equal to or lower than the above upper limit value to ensure stable selectivity during continuous processing. When the semiconductor substrate is rotated, the rotation speed is also dependent on the size and the like. However, from the same viewpoint as described above, it is preferably rotated at 50 rpm to 1000 rpm, more preferably at 50 rpm to 700 rpm. When it is set to rotate at a low speed, it is preferable to rotate at 50 rpm to 400 rpm.

In the case of the batch type, it is preferred to set the liquid bath to the above temperature range for the same reason as described above. The immersion time of the semiconductor substrate is not particularly limited, and is preferably It is set to 0.5 minutes to 30 minutes, more preferably 1 minute to 10 minutes. It is preferable to set the immersion time to be equal to or higher than the above lower limit value to ensure uniformity in the in-plane of etching. When the immersion time is equal to or less than the above upper limit value, the performance when the etching liquid is reused can be maintained, which is preferable.

In the piece-by-piece etching according to a preferred embodiment of the present invention, it is preferable that the semiconductor substrate is transferred or rotated in a specific direction, and an etching liquid is ejected in the space to bring the etching liquid into contact with the semiconductor substrate. The supply speed of the etching liquid or the rotation speed of the substrate is the same as described above.

In the configuration of the sheet-by-chip apparatus according to the preferred embodiment of the present invention, as shown in Fig. 4, it is preferable to provide an etching liquid while moving the discharge port (nozzle). Specifically, in the present embodiment, when an etching liquid is applied to the semiconductor substrate S having a layer containing TiN, the substrate is rotated in the r direction. On the other hand, the discharge port moves along a movement trajectory t extending from the central portion of the semiconductor substrate toward the end portion. As described above, in the present embodiment, the rotation direction of the substrate and the moving direction of the discharge port are set to be different directions, thereby moving the two relative to each other. As a result, the configuration is such that the etching liquid can be supplied to the entire surface of the semiconductor substrate without fail, and the uniformity of etching is preferably ensured.

The moving speed of the discharge port (nozzle) is not particularly limited, but is preferably 0.1 cm/s or more, and more preferably 1 cm/s or more. On the other hand, the upper limit of the moving speed is preferably 30 cm/s or less, more preferably 15 cm/s or less. The moving trajectory can be a straight line or a curve (for example, an arc shape). In either case, the speed of movement can be calculated from the distance of the actual trajectory line and the time it takes to move.

[residue]

In the manufacturing process of the semiconductor element, there may be a step of etching a metal layer or the like on the semiconductor substrate by plasma etching using a resist pattern or the like as a mask. Specifically, the metal layer, the semiconductor layer, the insulating layer, and the like are etched, and the metal layer or the semiconductor layer is patterned, or an opening such as a via hole or a wiring trench is formed on the insulating layer. In the above plasma etching, a resist used as a mask, or a residue derived from an etched metal layer, a semiconductor layer, or an insulating layer may be present on a semiconductor substrate. In the present invention, the residue thus generated by plasma etching is referred to as "plasma etching residue". Further, the "plasma etching residue" also includes an etching residue of the second layer (SiON or SiOC).

In addition, the resist pattern used as a mask is removed after etching. In the removal of the resist pattern, a wet method using a stripper solution; or a dry method using ashing such as plasma, ozone or the like can be used. In the above ashing, a residue obtained by deterioration of the plasma etching residue by plasma etching or a residue derived from the removed resist may be present on the semiconductor substrate. In the present invention, the residue thus produced by ashing is referred to as "ashing residue". In addition, a general term for a plasma etching residue, an ashing residue, or the like which appears on a semiconductor substrate and should be cleaned and removed may be simply referred to as "residue".

The plasma etching residue or the ashing residue as the post-etching residue (Post Etch Residue) is preferably washed and removed using a cleaning composition. The etching liquid of this embodiment can also be used as a cleaning liquid for removing the plasma etching residue and/or the ashing residue. Preferably, after the plasma ashing by plasma etching, The plasma etching residue and the ash residue are removed and used.

[processed object]

The material to be etched by applying the etching liquid of the present embodiment may be any, but a substrate having a first layer containing TiN is applied. Here, the layer (TiN layer) containing TiN means that oxygen may be contained, and in particular, when it is distinguished from a layer containing no oxygen, it may be referred to as a TiN layer or the like. In the present invention, the oxygen content of the TiN layer is preferably 10 mol% or less, more preferably 8.5 mol% or less, still more preferably 6.5 mol% or less. Further, when the concentration is low, the oxygen content is preferably less than 0.1 mol%. The lower limit of the oxygen content of the TiN layer does not particularly exist, and is actually 0.01 mol% or more. The adjustment of the oxygen concentration in the TiN layer of such a substrate can be performed, for example, by adjusting the oxygen concentration in the process chamber of the chemical vapor deposition (CVD) at the time of forming the TiN layer. In addition, the first layer contains TiN as its main component, but may contain other components in the range in which the effects of the present invention are exerted. This is also the same for other layers such as the second metal layer.

The first layer is preferably etched by a high etching rate. The thickness of the first layer is not particularly limited, and is actually about 0.005 μm to 0.3 μm in consideration of the configuration of a normal element. The etching rate [R1] of the first layer is not particularly limited, and is preferably 5 Å/min or more, more preferably 10 Å/min or more, and particularly preferably 50 Å/min or more in consideration of production efficiency. The upper limit of the etching rate [R1] of the first layer does not particularly exist, and is actually 500 Å/min or less (1 Å = 0.1 nm).

The method of the present invention is preferably applied to a semiconductor substrate having a second layer containing a metal such as Cu, W, Co, Ni, Ag, Ta, Hf, Pt, or Au. Among them, as The material of the second layer is preferably Cu or W.

Here, the technical significance of the metal layer will be described based on an example in which copper (Cu) and tungsten (W) are used as the above materials. In recent years, in response to the demand for higher speed of semiconductor devices (semiconductor devices), miniaturization of wiring patterns, and high integration, it is required to reduce the capacitance between wirings, improve the conductivity of wiring, and improve the electromigration resistance. . As a technique for meeting these requirements, a multilayer wiring technique using copper having excellent conductivity and excellent electromigration resistance as a wiring material and a low dielectric constant layer (Low-k layer) as an interlayer insulating layer has been attracting attention. The copper wiring generally functions as a copper diffusion preventing film for preventing diffusion of copper in the copper wiring; it is provided on a copper seed layer by a dual damascene process (for example, tantalum (Ta) And double layer of tantalum nitride (TaN).

On the other hand, the contact of the semiconductor element is usually set by replacing the tungsten plug of the two-pass damascene process used in the formation of the copper wiring and the via hole by a single damascene process. In such a multilayer wiring technique, a damascene method in which a recess such as a wiring trench or a through hole is formed in a low dielectric constant layer to embed copper therein is used. In this case, in order to form the concave portion by the etching precision in the low dielectric constant layer, it is necessary to use a mask including a material sufficiently high in the selection ratio of the low dielectric constant layer as the low dielectric constant layer. A mask when etching.

As the low dielectric constant layer, an organic material is usually used. Therefore, when the low dielectric constant layer is etched by using a photoresist layer containing the same organic material as a mask, the selection ratio is insufficient. In order to solve such a problem, it is proposed to use a hard mask layer containing an inorganic material such as a TiN film as a mask for etching. Moreover, the hard mask layer must be removed by a process in which the low dielectric constant layer is etched. In particular, in the etching of a wet process, it is desirable to selectively remove the hard mask (TiN layer) without etching a metal layer such as a tungsten plug or other wiring or a low dielectric constant layer material.

In order to remove the first layer (TiN) layer constituting the hard mask in the above-described form, it is assumed that the metal layer (second layer) is located at the bottom of the via hole or the trench (see FIGS. 1 and 2).

The etching rate [R2] of the second layer (metal layer) is not particularly limited, but is preferably not excessively removed, and is preferably 100 Å/min or less, and more preferably 50 Å/min or less. The lower limit of the etching rate [R2] of the second layer (metal layer) does not particularly exist, and is actually 0.001 Å/min or more.

The exposed layer of the metal layer (d in the drawing) is not particularly limited, and from the viewpoint that the advantages of the present invention become more remarkable, it is preferably 2 nm or more, and more preferably 4 nm or more. Similarly, from the viewpoint of the remarkable effect of the effect, the upper limit of the exposure width is actually 1000 nm or less, preferably 100 nm or less, and more preferably 20 nm or less.

Further, the method of the present invention is also preferably applied to a semiconductor substrate having a third layer containing a metal compound such as SiO, SiN, SiOC or SiON. In addition, in the present specification, when the composition of the metal compound is expressed by a combination of elements, it means that the composition is broadly included. For example, SiO refers to a thermal oxide film containing ruthenium and SiO ₂ , and is SiOx. The third layer is preferably suppressed at a low etch rate. The thickness of the third layer is not particularly limited, and is actually about 0.005 μm to 0.5 μm in consideration of the configuration of a usual element. The etching rate [R3] of the third layer is also preferably low, and the preferred range is the same as the above [R2].

In the selective etching of the first layer, the etching rate ratio ([R1]/[R2]) is not particularly limited, and it is preferably 2 or more, more preferably on the premise of an element having a high selectivity. It is 3 or more, and particularly preferably 5 or more. As the upper limit of the etching rate ratio, it is actually 50 or less. Further, regarding the etching rate ratio ([R1]/[R3]) of the first layer and the third layer, it is also preferable that the ratio of the first layer to the second layer ([R1]/[R2]) is the same. range.

[Manufacture of semiconductor substrate products]

In the present embodiment, it is preferable to manufacture a semiconductor substrate product having a desired structure by forming a semiconductor substrate on which a first layer and a second layer are formed on a germanium wafer; and applying etching on the semiconductor substrate Liquid, and selectively dissolve the above first layer. At this time, etching is performed using the above specific etching liquid. Preferably, the semiconductor substrate is subjected to dry etching or dry ashing before the etching step, and the residue generated in the step is removed.

In addition, in the present specification, each step of the etching and the method of manufacturing the semiconductor substrate are allowed to be applied in an order in which the steps of the present invention are appropriately changed within the range in which the effects of the present invention are exerted. In addition, when it is called "preparation", it means that it is prepared by synthesizing or blending a specific material, and includes supplying a specific person by purchase or the like. Further, in the present specification, the case where the etching liquid is to be used for etching each material of the semiconductor substrate is referred to as "application", but the embodiment is not particularly limited. For example, it is widely used to bring the etching liquid into contact with the substrate. Specifically, it may be etched by immersion by a batch, or may be etched by being sprayed one by one.

[Examples]

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

<Example 1 and Comparative Example 1>

The composition (% by mass) shown in Table 1 was contained in the components shown in Table 1 below, and the solution was adjusted to form an etching solution. In addition, the rest is water (ultra-pure water). The % in the table is all mass%.

(Method of manufacturing TiN substrate)

A TiN film having a surface oxygen concentration of less than 0.1 mol% was produced by a CVD (Chemical Vapor Depositon) on a commercially available germanium substrate. Further, the second layer (metal layer) was formed on the substrate by CVD in the same manner, and used as a test substrate in the table.

(etching test)

The test substrate described above was subjected to etching under the following conditions by a sheet-by-chip apparatus (SPS-Europe B.V., manufactured by POLOS (trade name)), and subjected to an evaluation test.

. Processing temperature: 60 ° C

. Spraying amount: 1L/min.

. Nozzle moving speed: 7cm/s

. Wafer speed 500rpm

In addition, the measurement of the etching rate (ER) of each layer was performed by ellipsometry (film thickness measurement method using a spectroscopic ellipsometer), and the average value of five points was evaluated.

(substrate surface oxygen concentration)

The surface oxygen concentration of the TiN layer is measured by an Electrochemical Spectroscopy for Chemical Analysis (ESCA) (Quantera manufactured by ULVAC PHI), and Ti in the depth direction from 0 nm to 30 nm is measured. The concentration distributions of O and N were calculated from 5 nm to 10 nm, respectively, and the average oxygen content was taken as the surface oxygen concentration.

(Method for measuring treatment temperature)

A radiation thermometer IT-550F (trade name) manufactured by Horiba, Ltd. was fixed to a height of 30 cm on the wafer in the above-described sheet-type device. The temperature was measured while flowing the chemical solution to the thermometer on the surface of the wafer 2 cm outside the center of the wafer. The temperature is digitally output by a radiation thermometer and continuously recorded by a computer. The temperature at which the temperature was stable for 10 seconds was averaged, and the obtained value was taken as the temperature on the wafer.

(Measurement of pH value)

The pH value in the table is a value measured by F-51 (trade name) manufactured by HORIBA at room temperature (25 ° C).

The test starting with C is a comparative example

*ER: Etching speed

**The amount of addition is all the mass % of the final composition (the total of composition A and composition B is 100%)

The corrosion inhibitor 2 is as described below.

VII-5-1 isopropyl naphthalenesulfonic acid

VII-1-6 dodecylbenzenesulfonic acid

A-1-1 Laurylpyridinium chloride

A-2-1 lauryl dimethyl benzyl ammonium chloride

A-2-2 dilauryl dimethyl ammonium chloride

S-2-3 Trimethyl lauryl ammonium chloride

O-1-1 polyoxyethylene ethyl lauryl ether

A-3-1 Tetrabutylphosphonium chloride

A-2-3 tetrabutylammonium hydroxide

A-2-4 benzyldimethyl stearyl ammonium chloride

According to the above results, according to the etching liquid of the present invention, it is possible to obtain a favorable etching selectivity for preferentially removing TiN with respect to a metal layer such as copper or tungsten.

Next, in Test 101, a TiN substrate having a surface oxygen concentration of TiN of 0.2 mol%, 1.9 mol%, 4.1 mol%, 6.0 mol%, 8.1 mol%, 9.9 mol%, and 12.1 mol% was produced, and the same was performed. As a result of the experiment, it was found that the defect performance of the TiN substrate (the surface after etching did not cause dot defects) became better.

The present invention has been described in connection with the embodiments thereof, and it is to be understood that the invention is not limited by the specific scope of the invention as set forth in the appended claims. Happening Under, it should be widely explained.

The present application claims the priority of Japanese Patent Application No. 2012-242731, the entire disclosure of which is hereby incorporated by reference.

1‧‧‧TiN layer (1st floor)

2‧‧‧SiON layer (3rd layer (1))

3‧‧‧SiOC layer (3rd layer (2))

4‧‧‧Cu/W layer (layer 2)

5‧‧‧ pathway

10‧‧‧Semiconductor substrate

d‧‧‧Exposed width

Claims (17)

An etching solution for treating a substrate having a first layer containing titanium nitride (TiN) and a second layer containing at least one metal selected from the group consisting of transition metals of Groups 3 to 11 to selectively remove the above The first layer contains an inorganic compound represented by the following formula (1), an oxidizing agent, and an anticorrosive agent for the second layer: Hal-Q (1) (Hal represents a halogen atom; Q represents an atom which becomes a monovalent cation or Atomic group). The etching solution according to claim 1, wherein the second layer has copper (Cu) or tungsten (W). The etching solution according to claim 1, wherein the halogen atom is a fluorine atom, a chlorine atom or a bromine atom. The etching solution according to claim 1, wherein the inorganic compound is hydrochloric acid (HCl). The etching solution according to claim 1, wherein the corrosion inhibitor is selected from the group consisting of a nitrogen-containing heteroaromatic compound, an oxygen-containing organic compound, an aromatic compound, a basic compound, an organic acid, an amine group-containing carboxylic acid compound, A group consisting of a surfactant and a quaternary phosphonium compound. The etching solution according to claim 1, wherein the corrosion inhibitor is represented by any one of the following formulas (A-1) to (A-3): (R ⁶¹ represents an alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, or an aralkyl group having 7 to 40 carbon atoms; and R ⁶² to R ⁶⁹ each independently represent an alkyl group having 1 to 30 carbon atoms; An alkenyl group having 2 to 30 carbon atoms or an aralkyl group having 7 to 30 carbon atoms; X ^- is a relative anion; R ⁷⁰ is a substituent; and m1 is an integer of 0 to 5). The etching solution according to claim 1, wherein the corrosion inhibitor comprises a compound represented by any one of the following formulas (I) to (IX): (R ¹ to R ³⁰ each independently represent a hydrogen atom or a substituent; in this case, each adjacent R ¹ to R ³⁰ may be bonded or condensed to form a cyclic structure; A represents a hetero atom; wherein A is a divalent At the time, R ¹ , R ³ , R ⁶ , R ¹¹ , R ²⁴ and R ²⁸ ) which are substituted on A are not present. The etching solution according to claim 1, wherein the corrosion inhibitor comprises a compound represented by the following formula (O-1): R ¹¹ -(-OR ¹³ -) _n -OR ¹² (O-1) (R ¹¹ and R ¹² are each independently a hydrogen atom or an alkyl group having 1 or more and 25 or less carbon atoms; and R ¹³ is a linear or branched alkyl group having 1 or more and 4 or less carbon atoms; When R ¹³ , they may be different; n is an integer of 1 or more and 8 or less). The etching solution according to claim 1, which contains 0.01% by mass to 10% by mass of the above-mentioned corrosion inhibitor. The etching solution according to claim 1, wherein the oxidizing agent is hydrogen peroxide. The etching solution according to claim 1, wherein the oxidizing agent is contained in an amount of 0.1% by mass to 30% by mass. The etching solution according to claim 1, wherein the inorganic compound is contained in an amount of 0.01% by mass to 10% by mass. The etching solution according to any one of claims 1 to 12, wherein a ratio of an etching rate (R1) of the first layer to an etching rate (R2) of the second layer (R1/R2) ) is 2 or more. An etching method for treating a substrate having a first layer containing titanium nitride (TiN) and a second layer containing at least one metal selected from the group consisting of transition metals of Groups 3 to 11 The inorganic compound, the oxidizing agent, and the etching solution for the corrosion inhibitor of the second layer described in the above formula (1) are applied to the substrate and subjected to the above treatment for selectively removing the first layer: Hal-Q... (Hal represents a halogen atom; Q represents an atom or a group of atoms which become a monovalent cation). The etching method according to claim 14, wherein the second layer has copper (Cu) or tungsten (W). The etching method according to Item 14 or 15, wherein the first liquid containing the oxidizing agent and the second liquid containing the inorganic compound and the corrosion inhibitor are separately prepared as the etching liquid. After mixing, it is applied to the above substrate in a timely manner. A method of manufacturing a semiconductor device, which comprises removing a first layer comprising titanium nitride (TiN) by an etching method according to any one of claims 14 to 16, and manufacturing a semiconductor from the remaining substrate element.