CN107304476B

CN107304476B - Etching composition for single-layer film or laminated film or etching method using the same

Info

Publication number: CN107304476B
Application number: CN201710262809.5A
Authority: CN
Inventors: 高桥秀树
Original assignee: Kanto Chemical Co Inc
Current assignee: Kanto Chemical Co Inc
Priority date: 2016-04-21
Filing date: 2017-04-20
Publication date: 2022-04-01
Anticipated expiration: 2037-04-20
Also published as: KR102596773B1; TWI731962B; KR20170120504A; CN107304476A; JP2017195311A; TW201809357A; JP6777420B2; KR20220108017A

Abstract

The invention provides an etching composition for etching a metal single layer film or a metal laminated film, which realizes a better etching rate than the prior art, is easy to control side etching, a taper angle, a cross-sectional shape and a pattern shape, and has a longer solution life while maintaining performance stability. An etching composition for etching a single-layer film formed of a metal selected from the group consisting of copper, titanium, molybdenum and nickel or a nitride thereof, a single-layer film formed of an alloy containing 1 or 2 or more selected from the group consisting of copper, titanium, molybdenum and nickel, or a laminated film containing 1 or 2 or more layers of the single-layer film, wherein the etching composition comprises oxazole, nitric acid, a peroxide and a water-soluble organic solvent.

Description

Etching composition for single-layer film or laminated film or etching method using the same

Technical Field

The present invention relates to an etching composition for a metal single layer film or laminated film which can be used for a flat panel display or the like, or an etching method using the same.

Background

For wiring materials of display devices such as flat panel displays, copper and alloys containing copper are used as low resistance materials. However, copper originally has insufficient adhesion to a substrate such as glass, and has a property of diffusing into a silicon semiconductor film. Therefore, in recent years, it has been known that by providing a barrier metal layer such as a titanium layer or a molybdenum layer as a barrier film between a substrate and a wiring material such as a copper layer, adhesion between the wiring material and a glass substrate is improved, and diffusion into a silicon semiconductor film is prevented. In addition, there is also a laminated film in which 3 layers of a cover (Japanese: キャップ) film are formed on the upper layer of a copper layer in order to prevent oxidation of the copper layer and the like.

As an etching solution for a copper and titanium layer laminate, for example, an etching solution having a ph of 1.5 to 2.5 containing hydrogen peroxide, nitric acid, a fluorine ion supply source, an azole, ammonium hydroxide, a hydrogen peroxide stabilizer and water (patent document 1), an etching solution containing ammonium persulfate, an organic acid, an ammonium salt, a fluorine-containing compound, a powdery glycol compound, an azole compound and water (patent document 3), an etching solution containing ammonium persulfate, an azole compound and water (patent document 3), and an etching solution containing a fluorine ion supply source, hydrogen peroxide, a sulfate, a phosphate, an azole compound and water (patent document 4) have been proposed.

Further, as an etching solution for a copper-molybdenum laminated film, for example, an etching solution containing at least one selected from a neutral salt, an inorganic acid and an organic acid, hydrogen peroxide, and a hydrogen peroxide stabilizer (patent document 5), an etching solution containing hydrogen peroxide, an inorganic acid containing no fluorine atom, an amine compound, an azole, and a hydrogen peroxide stabilizer (patent document 6), an etching composition containing ammonia, a compound having an amino group, and hydrogen peroxide in an aqueous medium and having a pH of more than 8.5 (patent document 7), and the like have been proposed.

Documents of the prior art

Patent document

Patent document 1 Japanese patent No. 5685204

Patent document 2 Japanese patent laid-open publication No. 2013-522901

Patent document 3 Japanese patent laid-open No. 2008-227508

Patent document 4 Japanese patent laid-open No. 2008-288575

Patent document 5 Japanese patent No. 4282927

Patent document 6 International publication No. 2011/099624

Patent document 7 Japanese patent laid-open No. 2010-232486

Summary of the invention

Technical problem to be solved by the invention

The etching solutions described in patent documents 1 and 4 to 7 have insufficient in-plane uniformity and may generate a large number of irregularities at the end of the resist pattern, and if the corrosion progresses further, mouse bite (mouse bite) having a shape such as a trace of cheese gnawing by a mouse may be generated, which may cause a decrease in yield or a fluctuation in the sectional shape of irregularities. The etching composition described in cited document 7 also has problems such as a short solution life and low storage stability in terms of usability. Further, for the etching solutions described in patent documents 2 and 3, persulfate is used, but if persulfate is used, the resist pattern end portions are more easily formed into the uneven shape than hydrogen peroxide. Further, there is a problem that the taper angle is not easily controlled and is easily lowered.

Accordingly, the present invention is directed to provide an etching composition for etching a metal single layer film or a metal laminated film, which can achieve a good etching rate, easily control a side etching, a taper angle, a sectional shape, and a pattern shape, and has a longer solution life while maintaining performance stability, for solving the above problems.

Technical scheme for solving technical problem

The present inventors have paid attention to the fact that phenylurea and phenolsulfonic acid used as a stabilizer for peroxide, an organic acid such as malonic acid and a chelating agent for increasing the amount of copper dissolved, a neutral salt for obtaining a buffer action of pH, and the like are factors causing a decrease in-plane uniformity in the course of earnest study for solving the above problems, and have found that an etching composition prepared by mixing a water-soluble organic solvent with a peroxide-containing etching composition can improve wettability to a metal substrate, smoothly etch a metal surface, and suppress local corrosion, and have further studied, and as a result, have completed the present invention.

That is, the present invention relates to the following.

[1] An etching composition for etching a single-layer film formed of a metal selected from the group consisting of copper, titanium, molybdenum and nickel or a nitride thereof, a single-layer film formed of an alloy containing 1 or 2 or more selected from the group consisting of copper, titanium, molybdenum and nickel, or a laminated film containing 1 or 2 or more layers of the single-layer film, wherein the etching composition comprises oxazole, nitric acid, a peroxide and a water-soluble organic solvent.

[2] The etching composition according to the above [1], wherein the vapor pressure of the water-soluble organic solvent at 25 ℃ is 2kPa or less.

[3] The etching composition according to the above [1] or [2], wherein the water-soluble organic solvent is selected from the group consisting of alcohols, glycols, diols, triols, ketones, carbonates, sulfoxides.

[4] The etching composition according to any one of the above [1] to [3], wherein the water-soluble organic solvent is selected from the group consisting of ethylene glycol, diethylene glycol and dipropylene glycol.

[5] The etching composition according to any one of the above [1] to [4], wherein the peroxide is selected from the group consisting of hydrogen peroxide, ammonium peroxysulfate, sodium peroxysulfate and potassium peroxysulfate.

[6] The etching composition according to any one of [1] to [5], further comprising phosphoric acid or a phosphate.

[7] The etching composition according to any one of the above [1] to [6], further comprising a compound selected from ammonium hydroxide and ammonia water.

[8] The etching composition according to any one of [1] to [7], further comprising fluorine or a fluorine compound.

[9] The etching composition according to [8], wherein the fluorine compound is selected from ammonium fluoride, acidic ammonium fluoride and hydrofluoric acid.

[10] The etching composition according to any one of the above [1] to [9], further comprising a urea compound.

[11] The etching composition as described in the above [10], wherein the urea compound is selected from the group consisting of phenylurea, allylurea, 1, 3-dimethylurea and thiourea.

[12] The etching composition according to any one of the above [1] to [11], further comprising an organic acid.

[13] The etching composition as recited in the above [12], wherein the organic acid is malonic acid or citric acid.

[14] The etching composition according to any one of the above [1] to [13], which comprises 1 to 15 mass% of a peroxide, 1 to 10 mass% of nitric acid, 0.005 to 0.2 mass% of an azole, 0.05 to 1.00 mass% of a fluorine compound, and 1 to 50 mass% of a water-soluble organic solvent.

[15] The etching composition according to any one of the above [1] to [14], which is an etching composition for etching a laminated film, wherein the laminated film is composed of a titanium/copper/titanium layer.

[16] The etching composition according to any one of the above [1] to [14], which is an etching composition for etching a laminated film, wherein the laminated film is composed of an alloy/copper/titanium layer formed of copper and nickel, and the titanium is located on a substrate side.

[17] The etching composition according to any one of the above [1] to [14], which is an etching composition for etching a laminated film, wherein the laminated film is composed of a single layer of copper/a single layer of molybdenum, respectively, and the single layer of molybdenum is located on a substrate side.

[18] The etching composition according to any one of the above [1] to [17], wherein the pH is lower than 7.0.

[19] An etching method for etching a single-layer film formed of a metal selected from the group consisting of copper, titanium, molybdenum and nickel or a nitride thereof, a single-layer film formed of an alloy containing 1 or 2 or more kinds selected from the group consisting of copper, titanium, molybdenum and nickel, or a laminated film containing 1 or 2 or more layers of the single-layer film, comprising a step of etching using the etching composition according to any one of the above [1] to [18 ].

[20] The method according to [19], wherein the method is used in a manufacturing process or a packaging process of a liquid crystal display, a color film, a touch panel, an organic EL display, electronic paper, MEMS, or IC.

ADVANTAGEOUS EFFECTS OF INVENTION

The etching composition of the present invention has improved wettability to metals due to the organic solvent contained in the etching composition, and can be used for etching a single-layer film or a laminated film at one time. Further, the etching rate is improved, the control of the side etching and the taper angle is easy, the in-plane uniformity is high, the etching of the resist edge and the cross-sectional shape can be made smooth, and a complicated and delicate substrate can be etched. In addition, the etching composition has good stability and can be used for a long time. Further, by supplementing the etching composition with a supply solution containing 1 or 2 or more components of the etching composition of the present invention, the solution life can be extended while maintaining the above-described performance. Therefore, it also contributes to reduction of manufacturing cost and safety in manufacturing the substrate.

In particular, a laminated film containing copper and titanium or a laminated film containing copper and molybdenum can easily suppress undercut (undercut) of titanium and molybdenum, which has been conventionally liable to occur. In addition, even when the titanium layer or the molybdenum layer having a thickness of about 100nm is present as the upper layer, the vicinity of the interface of the upper layer is prevented from being etched extremely. The single-layer film also has the effect of preventing the smoothness and cross-sectional shape of the end portions of the resist pattern from deteriorating. Further, even if a peroxide stabilizer, an organic acid or a chelating agent is added, the lowering of the in-plane uniformity and the generation of mouse bites at the ends of the resist pattern can be suppressed without further adding a stabilizer or a pH buffer.

Brief description of the drawings

FIG. 1 is a schematic cross-sectional view of a Cu/Ti substrate subjected to an etching treatment.

FIG. 2 is a schematic cross-sectional view of a Cu/Mo substrate with Mo undercut.

FIG. 3 is a schematic cross-sectional view of a CuNi/Cu/Ti substrate with a copper alloy in the form of a eave.

Fig. 4 is a schematic cross-sectional view of a Ti substrate subjected to etching treatment.

Fig. 5 is a schematic cross-sectional view of a Ti substrate in which the upper layer portion of Ti is etched extremely.

FIG. 6 is an SEM photograph of a cross section of a Cu/Ti substrate having a forward conical shape in cross section.

FIG. 7 is an SEM photograph of a cross section of a Cu/Mo substrate with Mo undercut.

FIG. 8 is an SEM photograph of a cross section of a CuNi/Cu/Ti substrate having a truncated top portion.

Fig. 9 is an SEM photograph of a cross section of a Ti substrate having a right circular cone shape in cross section.

Fig. 10 is an SEM photograph of the Ti substrate.

Fig. 11 is a schematic diagram of a cross-sectional shape of an end portion of a resist pattern when the etched CuNi/Cu/Ti substrate is viewed obliquely from above.

Fig. 12 is a schematic diagram of a cross-sectional shape of a CuNi/Cu/Ti substrate in which the resist pattern end portion has uneven irregularities when viewed from obliquely above.

Fig. 13 is an SEM photograph showing the cross-sectional shape of the resist pattern edge when the etched CuNi/Cu/Ti substrate is viewed obliquely from above.

Fig. 14 is an SEM photograph showing a cross-sectional shape of a CuNi/Cu/Ti substrate in which the resist pattern end portion has uneven irregularities when viewed from obliquely above.

Modes for carrying out the invention

Hereinafter, embodiments of the present invention will be described in detail.

In this specification, for example, Cu/Ti, CuNi/Cu/Ti, and the like are sometimes described, Cu/Ti means a 2-layer film of copper and titanium, and CuNi/Cu/Ti means an alloy of copper and nickel, and a 3-layer film of copper and titanium. In the sequence of layers, Cu/Ti represents an alloy in which copper is laminated on titanium, CuNi/Cu/Ti represents an alloy in which copper is laminated on titanium, and nickel is laminated on the copper. Therefore, the layer closest to the substrate surface in the laminated film is all titanium.

The etching composition of the present invention is a composition in which a resist is applied to a single-layer film and/or a laminated film on a substrate, a desired pattern mask is exposed and transferred, and a resist pattern is formed by development, and then the single-layer film and/or the laminated film is etched to finally form a wiring or an electrode pattern on the substrate. In this regard, as shown in fig. 1, the angle (taper angle) formed by the etched surface of the copper wiring end portion and the underlying substrate is preferably less than 90 °, more preferably 20 to 60 °, which is a right circular cone shape. In particular, in the case of a barrier metal layer containing no copper, for example, a single-layer film of Ti, Mo, or the like, the film thickness is small, and therefore, even at a high angle of 70 ° or 80 °, the actual substrate does not have a particularly significant problem, and therefore, the positive conical shape is included in a preferable range.

Further, the distance from the end of the resist to the barrier film provided under the wiring (side etching) is preferably within about 3 times the film thickness of the laminated film. More preferably within about 1.5 times. For example, if the Cu/Ti film thickness is

It is preferably within 2.0. mu.m, more preferably within 0.9. mu.m. As shown in fig. 2, the state in which the barrier metal layer under the copper layer is etched is called a so-called barrier metal undercut, and the undercut portion becomes a cavity and an open circuit state in this state, and thus, it cannot be used as a substrate. Therefore, this method is not preferable as etching.

Further, as shown in fig. 3, when a 3-layer laminated film in which a coating film is formed on a copper layer is etched, if the metal of the coating film is less soluble than copper, a eaves shape may be formed. The eave-like state is also an inverted cone, and the substrate cannot be used because it is in an open circuit state as described above, and therefore, it is not preferable for etching. A more preferable etching state of the single layer is a cross-sectional view of the Ti substrate shown in fig. 4. Namely, a right circular cone with a cone angle of 20 to 60 DEG, and a side etching of 0.9 μm or less. The state of the etching solution entering the interface between the resist and Ti is shown in a schematic cross-sectional view of the Ti substrate shown in fig. 5. The upper layer of Ti is extremely etched, which is obviously not preferable. Fig. 10 is an SEM photograph of a Ti substrate treated with a general etching composition containing hydrogen peroxide, ammonia water, and phosphate. The upper layer of Ti is etched extremely, which is not preferable.

Fig. 11 and 12 show the shapes of the resist pattern end portions when viewed obliquely from above. Fig. 11 shows a state where the smoothness of the etched end portion is high, and fig. 12 shows a state where the smoothness is low. The higher the smoothness of the etched end portion, the better. That is, the etching composition preferably satisfies the above conditions.

The etching composition of the present invention is a single-layer film or a laminated film of a metal formed on a glass or silicon substrate as an etching target. Further, the multilayer film may include 1 or 2 or more layers of the single-layer film made of the metal or the alloy.

In one aspect of the present invention, the single-layer film or the laminated film contains a nitride of a metal selected from the group consisting of copper, titanium, molybdenum, and nickel. A single-layer film of TiN or MoN or a laminated film containing them is preferable.

The titanium alloy or molybdenum alloy used for the single-layer film or laminated film contains titanium or molybdenum as a main component, but may contain other metals such as aluminum, magnesium, and calcium. The titanium alloy or molybdenum alloy contains titanium or molybdenum in an amount of 80 wt% or more, preferably 90 wt% or more, more preferably 95 wt% or more, based on the weight of the alloy.

The laminate film may have 2,3, 4 or 5 layers, preferably 2 or 3 layers. Examples of the 2-layer laminated film include Cu/Ti, Cu/MoTi, Cu/TiN, Cu/Mo, and Cu/MoN, but not limited thereto. A laminated film may be used in which a film of Ti, Mo, or an alloy layer thereof is formed as a barrier metal, and a film of Cu or a Cu alloy is further formed thereon.

Further, the 3-layer laminated film may be, for example, Ti/Cu/Ti, Mo/Cu/Mo, Ti/Cu/TiN, Mo/Cu/MoN, CuNi/Cu/Ti, CuNi/Cu/TiN, CuMgAl/Cu/CuMgAl, CuMgAlO/Cu/CuMgAl, etc., but is not limited thereto. When an oxide semiconductor such as IGZO is used for the channel layer, since the Cu electrode is exposed to an oxygen atmosphere, Ti, Mo, an alloy thereof, or the like is often used as the protective film. However, if these films are formed on the upper layer of copper, it is difficult to treat the copper with one solution or to unify the cross-sectional shape, so a copper alloy such as CuNi or CuMgAl is used as the coating film.

In particular, a multilayer thin film including a copper layer and a molybdenum layer is widely used for wiring of display devices such as flat panel displays, and the etching composition of the present invention is suitable for the multilayer film. In addition, in a film for forming an electrode or a wiring, a single-layer film often uses an alloy of titanium, molybdenum, nickel, or the like as a barrier alloy, and in order to suppress diffusion of silicon or the like, copper or a copper alloy is often formed on the barrier metal. The etching composition of the present invention is suitable not only for a single layer film of a barrier metal but also for selective etching of a copper or copper alloy film on a barrier metal.

Further, of the flat panel display, what controls light by liquid crystal is a TFT (Thin Film Transistor). The TFT has a gate electrode, a source electrode and a drain electrode, wherein the gate electrode is positioned at the lowest layer of the TFT, and the source electrode and the drain electrode are positioned at the upper layer. In terms of electrical characteristics, a gate electrode is often formed by a relatively thick Cu/Ti or Cu/Mo laminated film, and a source electrode and a drain electrode are sometimes formed by a thin film. For example, the copper of the gate is

The source and drain electrodes are made of copper

Etc., but are not limited thereto. Therefore, it is preferable to prepare the etching composition of the present invention so as to be able to cope with any film thickness.

The thickness of the laminated film is preferably set to

More preferably, it is

The thickness of copper film used for the laminated film is preferably set to

More preferably, it is

The thickness of the Ti or Mo alloy used for the laminated film is preferably set to

More preferably, it is

The etching composition of the present invention contains a water-soluble organic solvent. The water-soluble organic solvent is advantageous for controlling the etching rate, side etching, taper angle, etc., smoothing the end of the resist pattern, and controlling the cross-sectional shape. The water-soluble organic solvent and the water-compatible liquid used in the etching composition of the present invention are preferably used, and the water-soluble organic solvent having a vapor pressure of 2kPa or less at 25 ℃ is preferably used. Water-soluble organic solvents which are in a solid state at ordinary temperature are not included. Of these, alcohols, glycols, triols, ketones, amides, nitrogen-containing pentacyclic rings, carbonates, sulfoxides and the like are more preferable. Of course, 1 or 2 or more of these water-soluble organic solvents can be used in the etching composition of the present invention.

Further, the alcohol solvent used in the etching composition of the present invention is preferably a monohydric alcohol such as methanol, ethanol, propanol, 2-propanol, or 1-butanol, or a dihydric alcohol such as ethylene glycol, propylene glycol, or butylene glycol. Among them, propanol, 2-propanol and 1-butanol are preferred, and propanol and 2-propanol are more preferred.

The diol used in the etching composition of the present invention is preferably diethylene glycol, dipropylene glycol, 1, 3-propanediol, 1, 3-butanediol, 2, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, or the like. Among them, diethylene glycol, dipropylene glycol, 1, 3-propanediol, 1, 3-butanediol, 2, 3-butanediol, and 1, 4-butanediol are more preferable, and diethylene glycol, dipropylene glycol, and 1, 3-butanediol are particularly preferable.

The trihydric alcohol used in the etching composition of the present invention is preferably glycerin or the like.

The ketone used in the etching composition of the present invention is preferably acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, ethyl propyl ketone, dipropyl ketone, or the like. Among them, acetone is more preferable.

The amide used in the etching composition of the present invention is preferably N, N-dimethylformamide, N-dimethylacetamide, or the like. Among them, N-dimethylformamide is more preferable.

The nitrogen-containing five-membered ring used in the etching composition of the present invention is preferably N-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, or the like. Among them, 1, 3-dimethyl-2-imidazolidinone and N-methyl-2-pyrrolidone are more preferable.

The carbonate used in the etching composition of the present invention is preferably ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, or the like. Among them, ethylene carbonate is more preferable.

The sulfoxide used in the etching composition of the present invention may, for example, be dimethyl sulfoxide, and preferably is dimethyl sulfoxide.

The content of the water-soluble organic solvent in the etching composition of the present invention is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, from the viewpoint of suitably ensuring the etching rate, the control of side etching, taper angle, and the like, the smoothing of the resist pattern edge, and the control of the cross-sectional shape.

The etching composition of the present invention contains 1 or 2 or more peroxides. The peroxide has a function of oxidizing the copper wiring as an oxidizing agent. In particular molybdenum, has the function of oxidative dissolution. The peroxide is preferably hydrogen peroxide, ammonium peroxodisulfate, sodium peroxodisulfate or potassium peroxodisulfate, more preferably hydrogen peroxide or ammonium peroxodisulfate. The content of the peroxide in the etching composition of the present invention is preferably 1 to 15 mass%, more preferably 3 to 6 mass%, which facilitates control of the etching amount, from the viewpoint of easy management of hydrogen peroxide and ensuring an appropriate etching rate.

The etching composition of the present invention comprises nitric acid. The nitric acid facilitates the dissolution of copper and the like oxidized by the peroxide. The content of nitric acid in the etching composition of the present invention is preferably 1 to 10 mass%, more preferably 2 to 7 mass% from the viewpoint of obtaining a proper etching rate and obtaining a good wiring shape after etching.

The etching composition of the present invention contains 1 or 2 or more kinds of azoles. The azole facilitates control of side etching, taper angle, cross-sectional shape. As the azole used in the etching composition of the present invention, preferred are triazoles such as 1,2, 4-1H-triazole, 1H-benzotriazole, 5-methyl-1H-benzotriazole, 3-amino-1H-triazole and 3-amino-1H-1, 2, 4-triazole, tetrazoles such as 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole and 5-amino-1H-tetrazole, imidazoles such as 1H-imidazole and 1H-benzimidazole, thiazoles such as 1, 3-thiazole and 4-methylthiazole, and the like. Of these, triazole and tetrazole are more preferable, and 1,2, 4-1H-triazole, 3-amino-1H-1, 2, 4-triazole and 5-amino-1H-tetrazole (ATZ) are particularly preferable.

The content of azole in the etching composition of the present invention is preferably 0.005 to 0.2 mass%, more preferably 0.01 to 0.05 mass%, from the viewpoint of suppressing an increase in side etching after etching and obtaining a good wiring cross-sectional shape after etching.

The etching composition of the present invention may further comprise 1 or 2 or more kinds of phosphoric acid (phosphate) or phosphoric acid compounds. Phosphate ions brought about by phosphoric acid (phosphate) or a phosphoric acid compound contribute to control of the etching rate and control of the cone angle of copper, titanium, molybdenum, nickel, or an alloy thereof. The content of phosphoric acid (phosphate) or a phosphoric acid compound in the etching composition of the present invention is preferably 0.1 to 30.0 mass%, more preferably 1.0 to 4.0 mass%, from the viewpoint of facilitating control of the etching rate and the taper angle.

The phosphate ion is not particularly limited as long as it is generated from the etching composition, and is preferably phosphoric acid (phosphate), monoammonium phosphate, diammonium phosphate, monosodium phosphate, disodium phosphate, magnesium monohydrogen phosphate, magnesium dihydrogenphosphate, monopotassium phosphate, dipotassium hydrogen phosphate, calcium monohydrogen phosphate, or the like. These may of course be used alone or in combination. Among them, phosphoric acid (phosphate) is more preferable from the viewpoint of easy handling because it is liquid.

The etching composition of the present invention may further comprise 1 or 2 or more kinds of basic compounds. The basic compound contributes to pH control, improved wettability to fine parts, and improved in-plane uniformity. The basic compound is preferably an alkali metal hydroxide such as ammonium hydroxide, aqueous ammonia or hydroxide, more preferably an alkali metal hydroxide such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethyl (2-hydroxyethyl) ammonium hydroxide, lithium hydroxide, sodium hydroxide or potassium hydroxide, an alkaline earth metal hydroxide such as calcium hydroxide, strontium hydroxide or barium hydroxide, an alkali metal carbonate such as ammonium carbonate, lithium carbonate, sodium carbonate or potassium carbonate, an ammonium hydroxide such as tetramethylammonium hydroxide or choline, an organic amine such as ethylamine, diethylamine or hydroxyethylamine, or ammonia. Among them, tetramethylammonium hydroxide (TMAH) is particularly preferable.

The content of the basic compound in the etching composition of the present invention is preferably 1 to 20% by mass, more preferably 1 to 7% by mass, from the viewpoint of obtaining a good wiring cross-sectional shape after etching.

The etching composition of the present invention may further comprise 1 or 2 or more kinds of fluorine or fluorine compounds. The fluorine ions derived from fluorine or the fluorine compound contribute particularly to etching of the barrier film formed of the titanium-based metal. The fluorine ion is not particularly limited as long as it is generated from the etching composition, and is preferably hydrofluoric acid, ammonium fluoride, acidic ammonium fluoride, or the like. The above-mentioned substances can of course be used individually or in combination. Among them, ammonium fluoride, acidic ammonium fluoride and hydrofluoric acid are more preferable from the viewpoint of low toxicity to animals.

The content of fluorine or fluorine compound in the etching composition of the present invention is preferably 0.05 to 1.00 mass%, more preferably 0.1 to 0.5 mass%. When the content of the fluorine ion is within the above range, a satisfactory etching rate of the barrier film made of a titanium-based metal can be obtained without increasing the etching rate of the glass substrate. In this regard, when the titanium-containing layer is etched at once, the etching composition of the present invention preferably further contains 1 or 2 or more kinds of fluorine or fluorine compounds, and when the titanium-containing laminated film is not etched but only the other layer is selectively etched, the etching composition of the present invention preferably does not contain 1 or 2 or more kinds of fluorine or fluorine compounds.

The etching composition of the present invention may further comprise 1 or 2 or more urea-based hydrogen peroxide stabilizers. Urea hydrogen peroxide stabilizers help to inhibit the decomposition of peroxides. The urea-based hydrogen peroxide stabilizer is preferably phenylurea, allylurea, 1, 3-dimethylurea, thiourea or the like, and among them, phenylurea is more preferable. The content of the urea-based hydrogen peroxide stabilizer in the etching composition of the present invention is preferably 0.1 to 2.0 mass%, more preferably 0.1 to 0.3 mass% from the viewpoint that the decomposition inhibiting effect of hydrogen peroxide can be appropriately obtained.

The etching composition of the present invention may further comprise 1 or 2 or more organic acids. The organic acid has a role as a buffer for pH adjustment in the etching composition. The organic acid is preferably an ammonium salt, citric acid, sodium citrate, sodium dihydrogen citrate, disodium citrate and potassium citrate, acetic acid and salts thereof (e.g., ammonium acetate, calcium acetate, potassium acetate and sodium acetate), tartaric acid and salts thereof (e.g., sodium tartrate, sodium hydrogen tartrate and sodium potassium tartrate), Tris (hydroxymethyl) aminomethane (Tris) and salts thereof (e.g., Tris (hydroxymethyl) aminomethane hydrochloride), malonic acid, triammonium citrate, ammonium dihydrogen citrate, ammonium lactate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate and the like. Among them, citric acid, malonic acid, diammonium hydrogen phosphate, and ammonium dihydrogen phosphate are more preferable.

In addition to the above-mentioned components, the etching composition of the present invention may contain water, 1 or 2 or more kinds of various additives which are generally used in etching compositions, to such an extent that the effect of the etching composition is not impaired. The water is preferably water from which metal ions, organic impurities, particles and the like have been removed by distillation, ion exchange treatment, filter treatment, various adsorption treatments and the like, and particularly preferably pure water or ultrapure water.

In a preferred embodiment of the etching composition of the present invention, the etching composition of the present invention contains a peroxide, a fluorine or fluorine compound, nitric acid, oxazole, a water-soluble organic solvent and water, more preferably contains a peroxide, a fluorine or fluorine compound, nitric acid, oxazole, a basic compound, a water-soluble organic solvent and water, and still more preferably contains a peroxide, a fluorine or fluorine compound, nitric acid, oxazole, a basic compound, phosphoric acid, a water-soluble organic solvent and water.

On one side of the etching composition of the present invention, an etching composition containing a peroxide, a fluorine or fluorine compound, nitric acid, oxazole, an alkali compound, a urea-based hydrogen peroxide stabilizer, a water-soluble organic solvent and water, an etching composition containing a peroxide, nitric acid, oxazole, an alkali compound, phosphoric acid, a urea-based hydrogen peroxide stabilizer, a water-soluble organic solvent and water, or an etching composition containing a peroxide, a fluorine or fluorine compound, nitric acid, oxazole, an alkali compound, phosphoric acid, a urea-based hydrogen peroxide stabilizer, a water-soluble organic solvent and water is preferable. The etching composition of the present invention may vary in composition depending on the film to be subjected.

The etching composition of the present invention preferably has a pH of less than 7 because peroxide is easily decomposed when the pH is more than 7. In addition, in the case of etching the titanium-containing layer, the pH is preferably 4 or less from the viewpoint that titanium is easily dissolved.

Next, the method of etching a single-layer film made of copper, titanium, molybdenum, or nickel, a single-layer film made of an alloy containing copper, titanium, molybdenum, or nickel, or a laminated film containing the single-layer film according to the present invention includes a step of etching using the above-described etching composition. Further comprises a step of bringing the etching composition of the present invention into contact with an object to be etched. The object to be etched is as described above.

In addition, as a method of bringing the etching composition into contact with the object to be etched, a wet etching method such as a method of bringing the etching composition into contact with the object by dropping (single-wafer spin treatment) or spraying or a method of immersing the object in the etching composition can be generally used, and a method of bringing the object into contact by dropping (single-wafer spin treatment) the etching composition into the object or a method of immersing the object in the etching composition is preferred.

As for the use temperature of the etching composition, if the temperature of the etching solution composition is above 20 ℃, the etching speed is not too low, and the production efficiency is not significantly reduced; on the other hand, if the temperature is lower than the boiling point, the etching conditions can be kept constant by suppressing the composition change. From the above-mentioned viewpoint, the temperature of the etching treatment is preferably 15 to 60 ℃, particularly preferably 30 to 50 ℃. By increasing the temperature of the etching composition, the etching rate is increased; on the other hand, the appropriate treatment temperature can be determined in consideration of, for example, a small change in the composition of the etching solution composition.

In addition, a manufacturing process or a packaging process of a liquid crystal display, a color film, a touch panel, an organic EL display, electronic paper, MEMS, or IC may be included.

If etching is performed, the metal generated by etching or the like is dissolved in the etching composition. If the etching composition is continuously used, the JET and S/E, T/A change due to the amount of dissolved metal and decomposition of peroxide. If these properties are changed, the cross-sectional shape is also changed, and thus, it is impossible to continuously manufacture a product of the same type. Therefore, in general, for the purpose of cost reduction or the like, a replenishment solution is used for a long time by increasing the amount of metal such as copper dissolved therein, and the replenishment solution is added to the etching composition to replenish the organic acid consumed by the increase in the amount of metal dissolved therein. In this regard, in the present invention, 1 or 2 or more of the peroxide, nitric acid, fluorine and/or fluorine compound, TMAH, or water-soluble organic solvent used in the etching composition of the present invention may be added as a supply liquid to the used etching composition of the present invention. This can significantly prolong the life of the solution, as compared with the case where only the organic acid or the peroxide is added to the etching composition or both are added as the replenishment solution.

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

1. Production of Metal substrate

Preparation of Ti substrate

Titanium (Ti) was sputtered on glass as a substrate to form a barrier film made of titanium. Then, a resist is applied to the substrate,after exposure and transfer of the pattern mask, the film was developed to obtain a patterned titanium single layer film. Further, the film thickness of Ti is

The Ti substrate used in the following examples and comparative examples is referred to as the substrate.

Preparation of Cu/Ti substrate

Titanium (Ti) was sputtered on glass as a substrate to form a barrier film made of titanium. Then, copper is sputtered to form copper wiring. Next, a resist was applied, the pattern mask was exposed and transferred, and then developed to obtain a patterned copper/titanium multilayer thin film. Further, the film thickness of Cu/Ti is set to

The Cu/Ti substrate used in the following examples and comparative examples is referred to as the substrate.

Preparation of CuNi/Cu/Ti substrate

Titanium (Ti) was sputtered on glass as a substrate to form a barrier film made of titanium. Then, copper is sputtered to form copper wiring, and copper nickel (CuNi) of a copper alloy is sputtered to form a copper protective film. Next, a resist was applied, the pattern mask was exposed and transferred, and then developed to obtain a patterned copper alloy/copper/titanium multilayer film. Further, the film thickness of CuNi/Cu/Ti is

The CuNi/Cu/Ti substrates used in the following examples and comparative examples are referred to as the substrates.

Production of Cu/Mo substrate

Molybdenum (Mo) was sputtered on glass as a substrate to form a barrier film made of molybdenum. Then, copper is sputtered to form copper wiring. Next, a resist was applied, the pattern mask was exposed and transferred, and then developed to obtain a patterned copper/molybdenum multilayer thin film. Further, the Cu/Mo film thickness is

The Cu/Mo substrate used in the following examples and comparative examples is referred to as the substrate.

2. Etching test

2-1 etch test with addition of Water-soluble organic solvent

An etching composition (table 1) obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), and water was added to a beaker, and the temperature was stabilized in a constant temperature bath maintained at 35 ℃. While stirring the etching solution composition with a stirrer, a 1X 1cm Cu/Ti substrate was immersed in the etching solution composition, and the etching time was measured. The etching time measured at the time point when copper and molybdenum disappeared was taken as the proper amount of etching time, and about 1.5 times the proper amount of etching time was taken as the actual etching time (i.e., 50% excess etching time, which was recorded as 50% O.E.). Etching compositions containing 10, 20 and 30 wt% of dipropylene glycol (DPG) and etching compositions containing no DPG in the etching compositions shown in table 1 were prepared based on 100 wt% of the etching compositions shown in table 1.

[ Table 1]

ATZ 5-amino-1H-tetrazole

Next, the etching compositions were put into respective beakers, and each Cu/Ti substrate was immersed while being stirred by a stirrer, thereby performing an etching test. Each substrate used in the test was set as examples 1 to 3. Examples 1 to 3 are Cu/Ti substrates to which 10, 20 and 30 wt% of DPG was added to the etching compositions shown in Table 1 and subjected to an etching test. As for the etching time, 1.5 times the appropriate amount of etching time described in table 2 was used as the excess etching time. Then, each Cu/Ti substrate subjected to the test was subjected to a treatment of washing with water and drying, and then the cross-sectional shape was confirmed by SEM, and each performance of each substrate, such as the amount of side etching, the taper angle, the Ti residue, the smoothness of the resist pattern edge portion, and the cross-sectional shape, was evaluated. The results are summarized in Table 2.

[ Table 2]

Cu/Ti substrate

50％O.E.

DPG dipropylene glycol

In each example, Ti residues were good, and the resist pattern had good cross-sectional shape without unevenness in the edge part in terms of smoothness of the edge part. In addition, the SEM photograph of example 1 is shown in fig. 6.

Next, an etching test was performed using the same etching composition as described above, using a Ti substrate as the substrate, and each substrate was evaluated. The results are summarized in Table 3. Comparative example 1 refers to a Ti substrate to which DPG was not added to the etching composition of table 1 and which was subjected to an etching test, and examples 4 to 6 refer to Ti substrates to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 1, respectively, and which were subjected to an etching test. As a result, the substrate of comparative example 1 had a truncated Ti shape as shown in FIG. 3, and T/A could not be measured. However, the substrates of examples 4 to 6 showed good cross-sectional shape and improved smoothness of the end portions by adding DPG, and JET could be controlled by the concentration of DPG added. In addition, the SEM photograph of example 4 is shown in fig. 9.

[ Table 3]

Ti substrate

50％O.E.

DPG dipropylene glycol

For Ti residues, A showed good and B showed bad. Regarding the smoothness of the resist pattern edge, a indicates good, and B indicates poor. The defective portion means that the end portion is uneven. Regarding the cross-sectional shape, a indicates good, and B indicates bad (the same applies below).

2-2 etch test with addition of Water-soluble organic solvent

An etching test was performed using a composition obtained by adding DPG and a composition without DPG to an etching composition (table 4) obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (E) tetramethylammonium hydroxide (TMAH), and water. Etching tests were carried out using a Cu/Ti substrate, a Ti substrate, and a Cu/Mo substrate, respectively, under the same test conditions as described above.

[ Table 4]

TMAH tetramethylammonium hydroxide

The results of etching treatment of the Cu/Ti substrate are summarized in table 5. Comparative example 2 refers to a Cu/Ti substrate to which DPG was not added to the etching composition of table 4 and which was subjected to an etching test, and examples 7 to 9 refer to Cu/Ti substrates to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 4, respectively, and which was subjected to an etching test. The results show that the smoothness of the resist pattern edge can be improved by adding DPG to control JET and T/a in the laminated film.

[ Table 5]

Cu/Ti substrate

50％O.E.

DPG dipropylene glycol

The results of etching the Ti substrate are shown in table 6. Comparative example 3 refers to a Ti substrate to which DPG was not added to the etching composition of table 4 and which was subjected to an etching test, and examples 10 to 12 refer to Ti substrates to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 4, respectively, and which were subjected to an etching test. The results show that JET can be controlled by adding DPG, and the smoothness and the sectional shape of the end portion of the resist pattern can be improved.

[ Table 6]

Ti substrate

50％O.E.

DPG dipropylene glycol

The results obtained by etching the Cu/Mo substrates are summarized in Table 7. Comparative example 4 refers to a Cu/Mo substrate to which no DPG was added to the etching composition of table 4 and subjected to an etching test, and examples 13 and 14 refer to Cu/Mo substrates to which 10, 20 wt% of DPG was added to the etching composition of table 4 and subjected to an etching test, respectively. The results show that JET and T/A can be controlled by adding DPG to the monolayer film, as described above. The smoothness and cross-sectional shape of the end portions of the examples were all good.

[ Table 7]

Cu/Mo substrate

50％O.E.

DPG dipropylene glycol

2-3 etch test with addition of Water-soluble organic solvent

An etching test was performed using a composition obtained by adding DPG and a composition without DPG to an etching composition (table 8) obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (E) tetramethylammonium hydroxide (TMAH), (F) phosphoric acid and water. An etching test was performed using a CuNi/Cu/Ti substrate. An etching test was performed under the same test conditions as described above, except that the o.e. was set to 50% or 100%.

[ Table 8]

The results of the CuNi/Cu/Ti substrates treated with 50% o.e. are summarized in table 9. Comparative example 5 refers to a CuNi/Cu/Ti substrate to which DPG was not added to the etching composition of table 8 and which was subjected to an etching test, and examples 15 to 17 refer to a CuNi/Cu/Ti substrate to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 8, respectively, and which was subjected to an etching test. The results show that JET can be controlled by adding DPG. In each example, the Ti residue was good, and the smoothness of the edge of the resist pattern was good, the edge was not uneven, and the cross-sectional shape was good.

[ Table 9]

CuNi/Cu/Ti substrate

50％O.E.

DPG dipropylene glycol

The results of the CuNi/Cu/Ti substrates treated with 100% o.e. are summarized in table 10. Comparative example 6 is a CuNi/Cu/Ti substrate to which DPG was not added to the etching composition of table 8 and which was subjected to an etching test, and examples 18 to 20 are CuNi/Cu/Ti substrates to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 8, respectively, and which was subjected to an etching test. The results show that JET can be controlled by adding DPG, and the smoothness of the resist pattern end portion can also be improved.

[ Table 10]

CuNi/Cu/Ti substrate

100％O.E.

DPG dipropylene glycol

2-4 etch test with addition of Water-soluble organic solvent

An etching test was performed using a composition containing DPG and a composition containing no DPG, to an etching composition (table 11) obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (E) tetramethylammonium hydroxide (TMAH), (F) phosphoric acid, (G) phenylurea, and water. Etching tests were performed using a CuNi/Cu/Ti substrate, a Cu/Ti substrate, and a Cu/Mo substrate. The etching test was performed under the same test conditions as described above, except that the o.e. was changed to 50% or 100%.

[ Table 11]

The results of the CuNi/Cu/Ti substrates treated with 50% o.e. are summarized in table 12. Comparative example 7 refers to a CuNi/Cu/Ti substrate to which DPG was not added to the etching composition of table 11 and which was subjected to an etching test, and examples 21 to 23 refer to a CuNi/Cu/Ti substrate to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 11, respectively, and which was subjected to an etching test. The results show that the smoothness of the resist pattern end portions and the cross-sectional shape can also be improved by controlling JET, S/E, T/a by adding DPG. SEM photographs of comparative example 7 are shown in fig. 8 and 14, and SEM photographs of example 23 are shown in fig. 13.

[ Table 12]

CuNi/Cu/Ti substrate

50％O.E.

DPG dipropylene glycol

In addition, comparative example 8 is a CuNi/Cu/Ti substrate prepared separately from the etching compositions in table 11, in which an etching composition not mixed with phosphoric acid (i.e., an etching composition obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (E) tetramethylammonium hydroxide (TMAH), (G) phenylurea, and water) was prepared, and DPG was not added to the etching composition and used for an etching test. The results of comparative examples 7 and 8 show that if phosphoric acid is not present, the in-plane uniformity is greatly reduced, the S/E ratio becomes large, and the smoothness and cross-sectional shape of the edge portions are deteriorated. This is presumably due to the addition of phenylurea. However, if a component in which phosphoric acid is added to this component, that is, if DPG as a water-soluble organic solvent is further added to the etching composition of table 11, the control of S/E and T/a is easy, and the smoothness and cross-sectional shape of the resist pattern edge portion can be greatly improved. From this, it is presumed that the water-soluble organic solvent has an effect of further improving the effect of phosphoric acid.

The results of the CuNi/Cu/Ti substrates treated with 100% o.e. are summarized in table 13. Comparative example 9 is a CuNi/Cu/Ti substrate to which DPG was not added to the etching composition of table 11 and which was subjected to an etching test, and examples 24 to 26 are CuNi/Cu/Ti substrates to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 11 and which was subjected to an etching test. The results show that the smoothness of the resist pattern end portions and the cross-sectional shape can also be improved by controlling JET, S/E, T/a by adding DPG.

[ Table 13]

CuNi/Cu/Ti substrate

100％O.E.

DPG dipropylene glycol

The results of Cu/Ti substrates treated with 50% o.e. are summarized in table 14. Comparative example 10 refers to a Cu/Ti substrate to which DPG was not added to the etching composition of table 11 and which was subjected to an etching test, and examples 27 to 29 refer to Cu/Ti substrates to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 11 and which was subjected to an etching test. The results show that JET, S/E, T/A can be controlled by adding DPG. In each example, Ti residues were good, and the resist pattern had good cross-sectional shape without unevenness in the edge part in terms of smoothness of the edge part.

[ Table 14]

Cu/Ti substrate

50％O.E.

DPG dipropylene glycol

In addition, comparative example 11 is a Cu/Ti substrate in which, when the etching compositions of table 11 were prepared, etching compositions not mixed with phosphoric acid (i.e., etching compositions obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (E) tetramethylammonium hydroxide (TMAH), (G) phenylurea, and water) were separately prepared, and DPG was not added to the etching compositions and used in the etching test. The results of comparative examples 10 and 11 show that the resist pattern end portions and the cross-sectional shape are inferior because phosphoric acid is not contained. This is presumed to be the same as described above because phenylurea is added. However, if a component in which phosphoric acid is added to this component, that is, if DPG as a water-soluble organic solvent is further added to the etching composition of table 11, the control of S/E and T/a is easy, and the smoothness and cross-sectional shape of the resist pattern edge portion can be greatly improved. It is thus presumed that the water-soluble organic solvent has the effect of further improving the effect of phosphoric acid as described above.

The results of Cu/Mo substrates treated with 50% o.e. are summarized in table 15. Comparative example 12 refers to a Cu/Mo substrate to which DPG was not added to the etching composition of table 11 and which was subjected to an etching test, and examples 30 to 32 refer to Cu/Mo substrates to which 10, 20, and 30 wt% of DPG was added to the etching composition of table 11 and which were subjected to an etching test. From the results, it is clear that JET, T/A can be controlled by adding DPG.

[ Table 15]

Cu/Mo substrate

50％O.E.

DPG dipropylene glycol

2-5 etch test with addition of Water-soluble organic solvent

An etching test was performed using a composition obtained by adding DPG and a composition without DPG to an etching composition (table 16) obtained by mixing (a) hydrogen peroxide, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (E) tetramethylammonium hydroxide (TMAH), (F) phosphoric acid, (G) phenylurea and water. An etching test was performed using a Cu/Ti substrate. The etching test was performed under the same test conditions as described above with o.e. set to 50%.

[ Table 16]

The results of the Cu/Ti substrates are summarized in Table 17. Comparative example 13 refers to a Cu/Ti substrate to which no DPG was added to the etching composition of table 16 and subjected to an etching test, and example 33 refers to a Cu/Ti substrate to which 30 wt% of DPG was added to the etching composition of table 16 and subjected to an etching test. The results show that the addition of DPG controls JET and S/E, T/A suppresses the disappearance of the resist pattern, smoothes the edge of the resist pattern, and makes the cross-sectional shape a right circular cone. This confirmed that the Cu single-layer film also had an effect of adding a water-soluble organic solvent.

As described above, Mo and Ti are generally used as barrier metals used for Cu laminated films, and Ta, another metal, an alloy of a plurality of metals, or the like may be used depending on the application. In such a case, it is shown that if the etching composition of the present invention is used, only a single-layer film of Cu can be selectively etched with respect to the laminated film. This suggests that if selective etching in which only Cu is dissolved can be achieved as in the etching composition of the present invention when the barrier metal layer is treated with another etching composition, the laminated film can be treated to S/E or T/a within a predetermined range by combining the other etching compositions and performing two kinds of easy two-stage etching. It is also shown that when a substrate containing titanium is etched at once, it can be performed by an etching composition containing fluorine or a fluorine compound, and when a substrate containing titanium is selectively etched, it can be performed by an etching composition containing no fluorine or fluorine compound.

[ Table 17]

Cu/Ti substrate

50％O.E.

Selective etching of Cu (etching Cu only, not Ti)

DPG dipropylene glycol

2-6 etch test with additive addition

The etching tests were carried out using a composition obtained by adding an additive to an etching composition (table 18) obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ) and water, and a composition obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (H) DPG and water, and a composition to which no additive was added. Etching tests were performed using a Cu/Ti substrate and a Cu/Mo substrate. The etching test was performed under the same test conditions as described above with o.e. set to 50%. Malonic acid used as an additive was added for the purpose of improving the buffer effect of the solution and the solubility of Cu or Mo, and tetramethylammonium hydroxide (TMAH) was used for controlling the pH.

[ Table 18]

Investigation of pH Range

[ Table 19]

Investigation of pH Range

DPG dipropylene glycol

The results of the Cu/Ti substrates are summarized in tables 20 and 21. Comparative examples 14 to 18 are Cu/Ti substrates subjected to an etching test in which 0/2, 2/2, 2/3, 2/4 and 2/5 wt% of malonic acid/TMAH was added to the etching compositions shown in Table 18, respectively (Table 20). Examples 34 to 36 are Cu/Ti substrates prepared by adding 0/0, 2/2, and 2/3 wt% malonic acid/TMAH to the etching compositions shown in Table 19, respectively, and subjecting the substrates to an etching test (Table 21). The results show that the smoothness of the resist pattern end portions is improved by adding DPG. Since the solubility of Ti is greatly lowered at a pH of 5 or more, the Cu/Ti substrate is preferably at a pH of 4 or less.

[ Table 20]

Cu/Ti substrate

50％O.E.

TMAH tetramethylammonium hydroxide

[ Table 21]

Cu/Ti substrate

50％O.E.

TMAH tetramethylammonium hydroxide

The results of the Cu/Mo substrates are summarized in tables 22 and 23. Comparative examples 19 to 24 are Cu/Mo substrates subjected to an etching test in which 0/2, 2/2, 2/3, 2/4, 2/5 and 2/6 wt% of malonic acid/TMAH was added to the etching compositions shown in table 18, respectively (table 22). Examples 37 to 39 are Cu/Mo substrates prepared by adding 2/2, 2/3, and 2/4 wt% malonic acid/TMAH to the etching compositions shown in Table 19, respectively, and subjecting the substrates to an etching test (Table 23). The results show that the composition containing DPG suppressed the undercut of Mo, and therefore had a wider pH range than the composition containing no DPG, and also had an excellent effect of improving the S/E and the cross-sectional shape. Table 23 shows that no Mo undercut occurred at a pH below 4. However, table 22 and table 23 show that if the composition of pH4 is compared, the substrate etched with DPG added has very small S/E compared to the substrate without DPG added, so by adjusting the composition ratio, Mo undercut can be suppressed even with the composition of pH5 or pH 6. Since decomposition of hydrogen peroxide may be promoted at a pH of 7 or more, it is considered that a composition having a pH lower than 7 is effective. In addition, the SEM photograph of comparative example 21 is shown in fig. 7, and the SEM photograph of comparative example 22 is shown in fig. 13.

[ Table 22]

Cu/Mo substrate

50％O.E.

TMAH tetramethylammonium hydroxide

[ Table 23]

Cu/Mo substrate

50％O.E.

TMAH tetramethylammonium hydroxide

Next, comparative examples 25 to 30 shown below refer to Cu/Mo substrates prepared by separately preparing an etching composition not mixed with acidic ammonium fluoride (i.e., the etching composition shown by mixing (a) hydrogen peroxide, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ) and water) and subjecting the etching composition to an etching test by adding 0/2, 2/2, 2/3, 2/4, 2/4.5, and 2/5.5 wt% malonic acid/TMAH, respectively (table 24). The results of comparative examples 25 to 30 showed that the cross-sectional shape was good only at pH2 to 3, and Cu or Mo did not dissolve or Mo undercut at other pH's. Further, it was revealed that the acidic ammonium fluoride has an effect of suppressing the undercut of Mo, and that the effect of suppressing the undercut of Mo is further improved by adding DPG as a water-soluble organic solvent, as compared with comparative examples 19 to 24 treated with an etching composition containing the acidic ammonium fluoride.

[ Table 24]

Cu/Mo substrate

50％O.E.

TMAH tetramethylammonium hydroxide

2-7 etch test based on pH dependence

Etching tests were carried out using an etching composition (table 25) obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ) and water, and an etching composition (table 26) obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (H) DPG and water. An etching test was performed using a Cu/Ti substrate. The etching test was performed under the same test conditions as described above with o.e. set to 50%. Malonic acid used as an additive was added for the purpose of improving the buffer action of the solution and the solubility of Cu or Ti, and TMAH was used for controlling the pH.

[ Table 25]

[ Table 26]

The results of the Cu/Ti substrates are summarized in tables 27 and 28. Comparative examples 31 to 33 are Cu/Ti substrates subjected to the etching test with 10/2, 10/3, and 10/8 wt% of citric acid/TMAH added to the etching composition of table 25 (table 27), and examples 40 to 42 are Cu/Ti substrates subjected to the etching test with 10/2, 10/3, and 10/8 wt% of citric acid/TMAH added to the etching composition of table 26 (table 28). As a result, the S/E becomes larger with an increase in pH. However, the substrate to which DPG is added can suppress the increase in S/E more than the substrate to which DPG is not added. Further, the resist pattern end portion of the substrate to which no DPG is added is uneven, and the substrate to which DPG is added can be formed into a smooth end portion.

[ Table 27]

Cu/Ti substrate

50％O.E.

TMAH tetramethylammonium hydroxide

[ Table 28]

Cu/Ti substrate

50％O.E.

TMAH tetramethylammonium hydroxide

The results of the Cu/Mo substrates are summarized in tables 29 and 30. Comparative examples 36 to 39 are Cu/Ti substrates to which 10/2, 10/3, 10/8, and 10/10 wt% of citric acid/TMAH was added to the etching composition of table 25 and subjected to an etching test (table 29), and examples 43 to 46 are Cu/Mo substrates to which 10/2, 10/3, 10/8, and 10/10 wt% of citric acid/TMAH was added to the etching composition of table 26 and subjected to an etching test (table 30). The result was that the substrates treated with the compositions of table 25 all underwent undercut of Mo. However, when the S/E ratio is compared, the S/E ratio of the substrate to which no DPG is added is greatly increased with an increase in pH, and the S/E ratio of the substrate to which DPG is added is suppressed. Further, the resist pattern end portion of the substrate to which no DPG is added is uneven, and the substrate to which DPG is added can be smooth. The substrates of table 29 all underwent undercut of Mo. However, it is suggested that the same can be suppressed by adjusting the composition ratio as in the case of using malonic acid. In addition, it was also suggested that S/E could be inhibited by the addition of DPG. Since decomposition of hydrogen peroxide may be promoted at a pH of 7 or more, as in the case of using malonic acid instead of citric acid, a pH range lower than 7 is effective.

[ Table 29]

Cu/Mo substrate

50％O.E.

TMAH tetramethylammonium hydroxide

[ Table 30]

Cu/Mo substrate

50％O.E.

TMAH tetramethylammonium hydroxide

2-8 etch test with addition of Water-soluble organic solvent

An etching test was performed by adding a composition of 2-propanol (IPA), diethylene glycol (DEG), dimethyl sulfoxide (DMSO), 1, 3-Butanediol (BD), 1, 3-dimethyl-2-imidazolidinone (DMI), N-methyl-2-pyrrolidone (NMP), glycerol (Gly), N-dimethylacetamide (DMAc), and a composition not added to an etching composition (table 31) obtained by mixing (a) hydrogen peroxide, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (E) tetramethylammonium hydroxide (TMAH), (G) phenylurea, and water, respectively. An etching test was performed using a CuNi/Cu/Ti substrate. The etching test was performed under the same test conditions as described above with o.e. set to 50%.

[ Table 31]

The results of etching CuNi/Cu/Ti substrates with IPA as the water-soluble organic solvent are summarized in Table 32. Comparative example 40 is a CuNi/Cu/Ti substrate to which IPA was not added to the etching composition of Table 31 and which was subjected to an etching test, and examples 47 to 49 are CuNi/Cu/Ti substrates to which IPA was added in an amount of 10, 20, 30 wt% to the etching composition of Table 31 and which was subjected to an etching test. The results show that IPA can control JET and S/E, T/A, and smooth the resist pattern edge, and the cross-sectional shape can be a right circular cone, compared with the substrate without IPA.

[ Table 32]

CuNi/Cu/Ti substrate

50％O.E.

IPA 2-propanol

The results of etching the CuNi/Cu/Ti substrate using DEG and DMSO as the water-soluble organic solvents are summarized in table 33. Examples 50 to 52 refer to CuNi/Cu/Ti substrates to which 10, 20, and 30 wt% of DEG was added to the etching composition shown in Table 31 and subjected to the etching test, and examples 53 to 55 refer to CuNi/Cu/Ti substrates to which 10, 20, and 30 wt% of DMSO was added to the etching composition shown in Table 31 and subjected to the etching test. The results show that DEG and DMSO control JET and S/E, T/A, and smooth the resist pattern ends, and the cross-sectional shape is a right circular cone, compared with the substrate without DEG and DMSO.

[ Table 33]

CuNi/Cu/Ti substrate

50％O.E.

DEG diethylene glycol, DMSO dimethyl sulfoxide

The results of etching CuNi/Cu/Ti substrates using BD and DMI as water-soluble organic solvents are summarized in Table 34. Examples 56 to 58 are CuNi/Cu/Ti substrates prepared by adding BD in an amount of 10, 20, and 30 wt% to the etching composition shown in Table 31 and subjected to an etching test, and examples 59 to 61 are CuNi/Cu/Ti substrates prepared by adding DMI in an amount of 10, 20, and 30 wt% to the etching composition shown in Table 31 and subjected to an etching test. The results show that the BD and the DMI can control JET and S/E, T/A, make the end of the resist pattern smooth, and make the cross-sectional shape to be a right circular cone, compared with the substrate without addition.

[ Table 34]

CuNi/Cu/Ti substrate

50％O.E.

1, 3-butanediol as BD, 1, 3-dimethyl-2-imidazolidinone as DMI

The results of etching a CuNi/Cu/Ti substrate using NMP or Gly as a water-soluble organic solvent are summarized in table 35. Examples 62 to 64 are CuNi/Cu/Ti substrates prepared by adding NMP in an amount of 10, 20, and 30 wt% to the etching compositions in Table 31 and subjecting the substrates to an etching test, and examples 65 to 67 are CuNi/Cu/Ti substrates prepared by adding Gly in an amount of 10, 20, and 30 wt% to the etching compositions in Table 31 and subjecting the substrates to an etching test. The results showed that NMP and Gly also controlled JET and S/E, T/A, and smoothed the resist pattern ends, compared with the substrate without the addition of the additive, and the cross-sectional shape was a right circular cone.

[ Table 35]

CuNi/Cu/Ti substrate

50％O.E.

NMP N-methyl-2-pyrrolidone, Gly glycerol

The results of etching CuNi/Cu/Ti substrates using DMAc as a water-soluble organic solvent are summarized in Table 36. Examples 68 to 70 are CuNi/Cu/Ti substrates prepared by adding 10, 20 and 30 wt% DMAc to the etching compositions in Table 31 and subjected to an etching test. As a result, DMAc was also found to control JET and S/E, T/A, and to smooth the resist pattern edge and to make the cross-sectional shape a right circular cone, as compared with the substrate without DMAc.

[ Table 36]

CuNi/Cu/Ti substrate

50％O.E.

DMAc N, N-Dimethylacetamide

The above results show that by using a water-soluble organic solvent, JET and S/E, T/A can be controlled, and the resist pattern can be made smooth at the edge and the cross-sectional shape can be made to be a right circular cone.

2-9 etch test with peroxide

Etching tests were carried out using an etching composition (table 37) obtained by mixing (a) ammonium peroxodisulfate, (B) acidic ammonium fluoride, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (G) phenylurea and water. An etching test was performed using a CuNi/Cu/Ti substrate. The etching test was performed under the same test conditions as described above with o.e. set to 50%.

[ Table 37]

The results for the CuNi/Cu/Ti substrates are summarized in Table 38. Comparative example 41 refers to a CuNi/Cu/Ti substrate to which DPG was not added to the etching composition of table 37 and subjected to an etching test, and examples 71 and 72 refer to CuNi/Cu/Ti substrates to which 10, 20 wt% of DPG was added to the etching composition of table 37 and subjected to an etching test, respectively. The results show that the substrate with DPG added can control JET and S/E, T/A and can have a right circular cone shape in cross section, compared with the substrate without DPG added. This shows that ammonium peroxodisulfate can replace hydrogen peroxide because it can achieve almost the same effect as hydrogen peroxide even when it is a peroxide such as ammonium peroxodisulfate.

[ Table 38]

Cu/Ti substrate

50％O.E.

DPG dipropylene glycol

3. Solution life and replenishment test

3-1 solution Life evaluation test

An etching test was performed using an etching composition (table 39) obtained by mixing (a) hydrogen peroxide, (B) hydrofluoric acid, (C) nitric acid, (D) 5-amino-1H-tetrazole (ATZ), (E) TMAH, (G) phenylurea, (H) DPG, and water. The solution life evaluation test is a test for confirming a change in performance when the amount of copper dissolved increases. In addition, for the dissolution of copper, a test was performed in which copper powder was dissolved instead of the copper substrate. The substrates used for the tests were subjected to an etching test using a CuNi/Cu/Ti substrate. The etching test was performed under the same test conditions as described above with o.e. set to 50%.

[ Table 39]

DPG dipropylene glycol

The results for the CuNi/Cu/Ti substrates are summarized in Table 40. Example 74 refers to a CuNi/Cu/Ti substrate treated with an etching composition to which copper was not added to the etching composition of table 39, and examples 75 to 77 refer to CuNi/Cu/Ti substrates treated with etching compositions to which 1000, 2000, and 3000ppm of each of the etching compositions of table 39 were dissolved. Comparative examples 75 to 77 treated with an etching composition in which 0ppm to 2000ppm of copper was dissolved showed a gradual decrease in performance. In addition, comparative example 77, which was treated with an etching composition in which 3000ppm of copper was dissolved, showed a significant decrease in performance, resulting in generation of Ti residues. Not shown in the table below, copper itself is not completely dissolved into the etching composition if up to 4000ppm of copper is added.

[ Table 40]

CuNi/Cu/Ti substrate

50％O.E.

3-2 replenishment test of solution Life

Next, an etching composition obtained by mixing (a) hydrogen peroxide, (B) hydrofluoric acid, (C) nitric acid, (D) TMAH, and water was added as a replenishment solution to the etching composition in table 39 (table 41), and a replenishment test of the solution life was performed. The replenishment solution was added in a manner such that the etching composition was added in an amount of 1.8 vol% or 2.0 vol% per 1000ppm of the copper dissolved therein. The substrates used for the tests were subjected to an etching test using a CuNi/Cu/Ti substrate. The etching test was performed under the same test conditions as described above with o.e. set to 50%.

[ Table 41]

Supply liquid

DPG dipropylene glycol

The results for the CuNi/Cu/Ti substrates are summarized in Table 42. Example 78 refers to a CuNi/Cu/Ti substrate treated with an etching composition to which no additional copper powder and no make-up solution were added to the etching composition of table 39, and examples 79 to 82 refer to a CuNi/Cu/Ti substrate treated with an etching composition to which 8000, 16000, 24000, 32000ppm of copper powder and 14.4, 32.0, 46.8, and 62.4 vol% of the make-up solution of table 14 were added to the etching composition of table 39, respectively. The results showed that in example 77, a Ti residue was produced when the amount of copper dissolved was 3000ppm, whereas in example 82, no Ti residue was produced even when 32000ppm of copper was dissolved. Further, it was also shown that the performance was substantially equal to the initial performance. It was thus confirmed that the addition of a composition containing a peroxide, nitric acid, fluorine and/or a fluorine compound, TMAH, a water-soluble organic solvent, or the like to the used etching composition of the present invention as a supply solution can prolong the solution life.

[ Table 42]

CuNi/Cu/Ti substrate

50％O.E.

Possibility of industrial utilization

When etching is performed using the etching composition of the present invention, a single-layer film and/or a laminated film can be etched at a time, a complicated and delicate substrate can be manufactured, and high productivity can be achieved. In addition, a substrate manufactured by an etching method using the etching composition can be used for higher performance flat panel displays and the like. Further, by using the replenishment solution, the solution life is prolonged, which contributes to cost reduction in substrate production and can improve safety.

Claims

1. A method for etching a single-layer film made of titanium, a single-layer film made of an alloy containing 80 wt% or more of titanium, or a laminated film containing 1 or 2 or more of the single-layer films, which comprises a step of etching with an etching composition containing oxazole, nitric acid, a peroxide and a water-soluble organic solvent.

2. The method according to claim 1, wherein the vapor pressure of the water-soluble organic solvent at 25 ℃ is 2kPa or less.

3. The method of claim 1, wherein the water soluble organic solvent is selected from the group consisting of alcohols, glycols, diols, triols, ketones, carbonates, sulfoxides.

4. The method according to claim 1, wherein the water-soluble organic solvent is selected from the group consisting of ethylene glycol, diethylene glycol and dipropylene glycol.

5. The method of claim 1, wherein the peroxide is selected from the group consisting of hydrogen peroxide, ammonium peroxysulfate, sodium peroxysulfate, and potassium peroxysulfate.

6. The method of claim 1, wherein the etching composition further comprises phosphoric acid or a phosphate.

7. The method of claim 1 or 6, wherein the etching composition further comprises a compound selected from the group consisting of ammonium hydroxide and ammonia.

8. The method of claim 1 or 6, wherein the etching composition further comprises fluorine or a fluorine compound.

9. The method of claim 8, wherein the fluorine compound is selected from the group consisting of ammonium fluoride, acidic ammonium fluoride, and hydrofluoric acid.

10. The method of claim 1 or 6, wherein the etching composition further comprises a urea compound.

11. The method of claim 10, wherein the urea compound is selected from the group consisting of phenylurea, allylurea, 1, 3-dimethylurea, and thiourea.

12. The method of claim 1 or 6, wherein the etching composition further comprises an organic acid.

13. The method of claim 12, wherein the organic acid is malonic acid or citric acid.

14. The method according to claim 1 or 6, wherein the etching composition comprises 1 to 15 mass% of the peroxide, 1 to 10 mass% of the nitric acid, 0.005 to 0.2 mass% of the azole, 0.05 to 1.00 mass% of the fluorine compound, and 1 to 50 mass% of the water-soluble organic solvent.

15. The method of claim 1 or 6, wherein the laminate film is a titanium/copper/titanium layer.

16. The method of claim 1 or 6, wherein the etching composition has a pH below 7.0.

17. The method according to claim 1 or 6, which is used in a manufacturing process or a packaging process of a liquid crystal display, a color film, a touch panel, an organic EL display, electronic paper, MEMS, or IC.