KR20060094487A - Etchant compositions for metal laminated films having titanium and aluminum layer - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a titanium and aluminum metal laminated film etching liquid composition, and more particularly, a layer made of titanium or titanium mainly formed by sputtering on an insulating film substrate such as glass, a silicon substrate, and a compound semiconductor substrate. And a metal laminated film containing a layer composed of aluminum or an alloy containing aluminum as its main component, and the concentration of the fluorine compound capable of collectively etching the laminated film by controlling the taper angle at 30 to 90 ° without damaging the substrate or the like. However, it is related with the etching liquid composition which is 0.01-5 mass% (except hydrofluoric acid) and 0.1-50 mass% of the density | concentration of a specific oxidizing agent.

Etching liquid composition, titanium, aluminum

Description

Etchant compositions for metal laminated films having titanium and aluminum layer

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the wiring process of the metal laminated | multilayer film containing the layer which consists of titanium or the titanium main alloy formed on the insulating substrate, and the layer which consists of aluminum or the aluminum main alloy.

<Description of the symbols for the main parts of the drawings>

1: glass substrate 2: titanium or titanium alloy film

3: aluminum or aluminum alloy film 4: resist

a: Gate electrode after etching with etching liquid of this invention (approximately uniform taper shape and taper shape of 40 degrees or less)

b: source or drain electrode (90 degree taper angle) after etching with the etching liquid of this invention

This invention relates to the etching liquid composition of the metal laminated film used for the gate, the source, and the drain electrode of a liquid crystal display.

Alloys in which impurities such as neodium, silicon, copper and the like are added to aluminum or aluminum are used for gate, source and drain electrode materials of liquid crystal displays because they are inexpensive and have very low resistance.

However, since aluminum or aluminum alloy is slightly poor in adhesion to a glass substrate, which is a base film, and is easily corroded by chemical liquids or heat, a molybdenum or molybdenum alloy film is used on and / or under the aluminum or aluminum alloy. Used as an electrode material as a laminated film, and has collectively etched the laminated film with an etchant using phosphoric acid or the like.

In recent years, the price of molybdenum or molybdenum alloys has risen, and titanium or a titanium alloy has attracted attention for the purpose of further improving the corrosion resistance by chemical liquids and heat. Phosphoric acid for molybdenum etching and the like cannot be used to etch titanium or a titanium alloy, and dry etching such as reactive ion etching (RIE) using a halogen-based gas is performed on a semiconductor substrate as a method of etching a titanium-aluminum metal laminate film. . Although RIE is controlled to have a tapered shape by anisotropic etching, it is disadvantageous in terms of cost because an expensive vacuum device or a high frequency generator is required, and therefore, it is desired to develop a batch etching solution that can reduce processing time at a lower cost. .

On the other hand, in the manufacturing process of a semiconductor device, when etching the metal thin film which has titanium as a main component, it is generally known to use hydrofluoric acid type etching liquid (for example, patent document 1: Unexamined-Japanese-Patent No. 59-). 124726). Moreover, it is also known that etching of titanium or a titanium alloy is possible with the etching liquid using ammonia water-hydrogen peroxide water (for example, patent document 2: Unexamined-Japanese-Patent No. 6-310492).

However, when a hydrofluoric acid etching solution is used, it cannot be used because it damages the underlying glass substrate, silicon substrate, and compound semiconductor substrate. In addition, when ammonia water-hydrogen peroxide water is used, bubbles are generated due to decomposition of the hydrogen peroxide water, bubbles are adhered to the substrate, so that etching is incomplete, or the life is shortened.

In addition, the present invention used for etching liquids such as glass substrates is different from the present invention. However, hydrogen peroxide, fluorides, inorganic acids and fluorine-based surfactants are used as etching liquids for the purpose of removing and smoothing the surface scale of titanium or titanium alloys used in ornaments and electronic parts. Although a composition containing as an essential component is disclosed (Patent Document 3: Japanese Patent Laid-Open No. 2004-43850), a composition comprising a layer made of titanium or an alloy containing titanium as a main component and a layer made of aluminum or an alloy containing aluminum as a main component It is not clear about etching a metal laminated film. Moreover, although the aqueous solution containing a persulfate and a fluoride is disclosed as a metal laminated film etching liquid which consists of a titanium layer and a copper layer (patent document 4: Unexamined-Japanese-Patent No. 2001-59191), the metal laminated body which consists of an aluminum layer and a titanium layer is disclosed. It is not etched into the film.

As such, no suitable means for collectively etching the titanium-aluminum metal laminate film has been developed.

Accordingly, the inventors of the present invention, while conducting research to solve the above problems, the etching solution of the fluorine compound and the oxidizing agent excluding hydrofluoric acid is composed of a layer composed of titanium or an alloy mainly composed of titanium and aluminum or aluminum as the main component It was found that a metal laminate film including a layer made of an alloy can be etched in a very suitable manner, and further research was conducted to complete the present invention.

An object of the present invention is to provide an etching solution capable of collectively etching a titanium-aluminum-based metal laminate film which has solved the above problems.

The present invention provides a fluorine compound (except hydrofluoric acid) and an oxidizing agent, which are used to collectively etch a metal laminated film comprising a layer composed of titanium or an alloy mainly composed of titanium and a layer composed of aluminum or an alloy composed mainly of aluminum. It provides an etching solution composition comprising a.

In the etching solution composition according to the present invention, the fluorine compound is at least one or two or more selected from hexafluorosilicate and a salt of hydrofluoric acid or silicic hexafluoride with a metal or ammonia.

In the etching liquid composition according to the present invention, the oxidizing agent is nitric acid, ammonium nitrate, ammonium sulfate, ammonium persulfate, potassium persulfate, perchloric acid, ammonium perchlorate, sodium perchlorate, potassium perchlorate, periodic acid, sodium periate, peroxide At least one selected from potassium iodide, methanesulfonic acid, hydrogen peroxide, sulfuric acid, and ethylenediamine sulfate.

In the etching liquid composition according to the present invention, the concentration of the fluorine compound is 0.01 to 5% by mass, and the concentration of the oxidant is 0.1 to 50% by mass.

In the etching liquid composition according to the present invention, the oxidizing agent is nitric acid or methanesulfonic acid.

Furthermore, in the etching solution composition according to the present invention, the oxidizing agent is ammonium nitrate, ammonium sulfate, ammonium persulfate, potassium persulfate, perchloric acid, ammonium perchlorate, sodium perchlorate, potassium perchlorate, periodic acid, sodium periate, peroxide At least one selected from potassium iodide, hydrogen peroxide, sulfuric acid, and ethylenediamine sulfate is further included.

The etching liquid composition according to the present invention further includes at least one selected from amid sulfuric acid, acetic acid and hydrochloric acid.

In the etching liquid composition according to the present invention, the base substrate of the metal laminate film is a glass substrate for liquid crystal display.

In the etching liquid composition according to the present invention, the base substrate is a silicon substrate or a compound semiconductor substrate for a semiconductor device.

Furthermore, the etching liquid composition according to the present invention has a taper angle of 30 to 90 ° after etching of a metal laminate film including a layer made of titanium or an alloy containing titanium as a main component and a layer made of aluminum or an alloy containing aluminum as its main component. Used to

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

The etching liquid composition of this invention makes it a summary that it consists of a fluorine compound (but except hydrofluoric acid), an oxidizing agent, and water.

The fluorine compound used in the etching solution of the present invention is considered to be mainly etched by dissolving the titanium oxide on the metal laminate film oxidized by the oxidizing agent which is a component of the etching solution. Any fluorine compound other than hydrofluoric acid may be used as the fluorine compound used in the etching solution of the present invention, but one or two or more selected from silicic acid hexafluoride or a salt of hydrofluoric acid or silicic acid hexafluoride with a metal or ammonia, for example For example, ammonium fluoride, potassium fluoride, calcium fluoride, ammonium hydrogen fluoride, potassium hydrogen fluoride, sodium fluoride, magnesium fluoride, lithium fluoride, silica hexafluoride, ammonium hexafluoride, sodium hexafluoride, potassium hexafluoride is preferable, and especially ammonium fluoride And ammonium hydrogen fluoride is preferred.

Moreover, the oxidizing agent used for the etching liquid of this invention plays a role as an etching initiator by oxidizing titanium or a titanium alloy on a metal laminated film. The oxidizing agent used in the etching solution of the present invention is nitric acid, ammonium nitrate, ammonium sulfate, ammonium persulfate, potassium persulfate, perchloric acid, ammonium perchlorate, sodium perchlorate, potassium perchlorate, periodic acid, sodium periodate, potassium periodate, It is 1 type, or 2 or more types chosen from methanesulfonic acid, hydrogen peroxide, sulfuric acid, and ethylenediamine sulfate, and nitric acid, ammonium persulfate, and methanesulfonic acid are preferable.

Nitrogen-containing organic compounds sulfates other than ammonium sulfate and ethylenediamine sulfate, for example, sulfates such as piperazine, 1- (2-aminoethyl) piperazine and 1-aminomethylpiperazine can be used as oxidizing agents, Ammonium sulfate and ethylene diamine are preferable at the point of (portability).

Nitric acid or methanesulfonic acid is particularly preferable because the taper angle can be made low even at low concentration, and for example, 40 ° or less. Although oxidizing agents other than nitric acid and methanesulfonic acid have a low effect of reducing the taper angle, they are preferable because the damage of the resist is small and the side etching amount can be controlled. The etching liquid containing the fluorine compound and nitric acid or methanesulfonic acid can control the taper angle to 40 ° or less, and further, at least one selected from oxidizing agents other than nitric acid and methanesulfonic acid, or amide sulfuric acid, acetic acid, and hydrochloric acid. By adding, a taper angle can be controlled between 30-90 degrees.

Preferred compositions of the etching liquid composition of the present invention include ammonium fluoride and nitric acid and perchloric acid, ammonium fluoride and nitric acid and sulfuric acid, ammonium fluoride and nitric acid in a combination using two or more oxidants in addition to ammonium fluoride and nitric acid, ammonium fluoride and methanesulfonic acid, Perchloric acid and methanesulfonic acid, ammonium fluoride and nitric acid, perchloric acid and sulfuric acid are preferred.

Moreover, in order to improve the substrate and wetting, you may add and use the surfactant and the organic solvent generally used for the said etching liquid.

The etching solution of the present invention comprises a metal comprising a layer made of titanium or titanium based alloys and a layer made of aluminum or an aluminum alloy as a main component formed on the insulating substrate made of a glass substrate or the like and sputtered on silicon or a compound semiconductor substrate. It is suitable for etching a laminated film, for example, a metal laminated film made of titanium / aluminum, aluminum / titanium, titanium / aluminum / titanium, and the concentration of the fluorine compound in the etching solution is 0.01 to 5% by mass, preferably 0.1 to 1 mass%, the concentration of the oxidizing agent is 0.1 to 50 mass%, preferably 0.5 to 10 mass%.

When the concentration of the fluorine compound is lower than 5% by mass, the side of the metal laminated film including a layer made of titanium or an alloy containing titanium as a main component and a layer made of aluminum or an alloy containing aluminum as a main component without damaging the underlying glass. When the amount of etching is suppressed and higher than 0.01% by mass, the etching nonuniformity of titanium or titanium alloy is reduced, and the shape after etching is good. When the content of the oxidizing agent is lower than 50% by mass, the side etching amount of the metal laminated film including the layer made of titanium or an alloy mainly composed of titanium and the layer made of aluminum or an alloy composed mainly of aluminum is suppressed, and also the damage of the resist occurs. If not higher than 0.1% by mass, the etching rate of titanium or titanium alloy is fast and efficient.

In addition, appropriately controlling the taper angle is carried out by using nitric acid or methanesulfonic acid alone and other oxidizing agents alone or in a suitable combination, in particular, in order to achieve 30 to 90 °. In this case, it is preferable that nitric acid or methanesulfonic acid is 0.1-30 mass%, especially 0.5-15 mass%, and other oxidizing agent is 0.1-20 mass%, especially 0.5-15 mass%.

In particular, in order to make a taper angle 40 degrees or less, it is preferable to use nitric acid or methanesulfonic acid.

In addition, when it contains further at least 1 sort (s) chosen from amid sulfuric acid, acetic acid, or hydrochloric acid, these concentration is preferably 0.01-10 mass%, especially 0.5-5 mass%.

Although the base substrate of the metal laminated film which the etching liquid of this invention etches is not restrict | limited, A glass substrate is preferable when titanium and an aluminum metal laminated film are used for a liquid crystal display, A silicon substrate and a compound semiconductor substrate are used for a semiconductor device. This is preferred.

Hereinafter, an Example and a comparative example demonstrate this invention further in detail. However, the following examples are merely to illustrate the content of the present invention, the present invention is not limited by the following examples.

< Example  1-25

As shown in FIG. 1, a substrate on which the titanium (700 ms) / aluminum (2500 ms) / titanium (200 ms) was formed by sputtering on the glass substrate 1 was prepared.

Next, it patterned on the titanium / aluminum / titanium metal laminated film using the resist 4, and was immersed in the etching liquid of Examples 1-25 of Table 1 (etching temperature 30 degreeC). Thereafter, the resultant was washed with ultrapure water and dried with nitrogen blow, and then the shape of the substrate was observed under an electron microscope. The results are shown in Table 1.

< Comparative example  1 ~ 2>

Titanium / aluminum / titanium formed on the glass substrate used in the above example by sputtering was immersed in an etching solution composed of the components of Comparative Examples 1 to 2 in Table 1, and was treated in the same manner as in the above example. The results are shown in Table 1 together.

 Etching Liquid Composition Taper Angle (°) Damage to glass substrate Damage to the resist Example 1 Ammonium fluoride: nitric acid = 0.2 mass%: 3 mass% 35 none none Example 2 Ammonium fluoride: 0.2 mass%: 10 mass% 30 none none Example 3 Silicate hexafluoride: nitric acid = 2.0 mass%: 10 mass% 30 none none Example 4 Ammonium fluoride: Ammonium persulfate = 0.5 mass%: 20 mass% 85 none none Example 5 Ammonium fluoride: Methane sulfonic acid = 0.5 mass%: 20 mass% 30 none none Example 6 Ammonium fluoride: Nitric acid: Ammonium persulfate = 0.3% by mass: 5% by mass: 10% by mass 40 none none Example 7 Ammonium fluoride: Nitric acid: Ammonium nitrate = 0.3 mass%: 5 mass%: 10 mass% 30 none none Example 8 Ammonium fluoride: Nitric acid: Ammonium persulfate = 0.3% by mass: 1% by mass: 5% by mass 80 none none Example 9 Ammonium fluoride: Nitric acid: Ammonium persulfate = 0.3% by mass: 3% by mass: 5% by mass 55 none none Example 10 Ammonium fluoride: Nitric acid: Ammonium persulfate = 0.3 mass%: 5 mass%: 5 mass% 40 none none Example 11 Ammonium fluoride: nitric acid: amide sulfuric acid = 0.55% by mass: 2% by mass: 0.75% by mass 35 none none Example 12 Ammonium fluoride: nitric acid: perchloric acid: amide sulfuric acid = 0.55% by mass: 1% by mass: 1% by mass: 0.5% by mass 35 none none Example 13 Ammonium fluoride: nitric acid: perchloric acid: amide sulfuric acid = 0.2% by mass: 1% by mass: 1% by mass: 0.75% by mass 40 none none Example 14 Ammonium fluoride: Nitric acid: Perchloric acid: Methanesulfonic acid = 0.2% by mass: 1% by mass: 1% by mass: 2% by mass 40 none none Example 15 Ammonium fluoride: Nitric acid: Perchloric acid: Methanesulfonic acid = 0.55% by mass: 0.5% by mass: 0.5% by mass: 1% by mass 45 none none Example 16 Ammonium fluoride: Perchloric acid: Methanesulfonic acid = 0.2 mass%: 4 mass%: 0.5 mass% 55 none none Example 17 Ammonium fluoride: Perchloric acid: Sulfuric acid = 0.2 mass%: 4 mass%: 1 mass% 50 none none Example 18 Ammonium fluoride: Nitric acid: Perchloric acid: Sulfuric acid = 0.2% by mass: 0.5% by mass: 4% by mass: 2% by mass 50 none none Example 19 Ammonium fluoride: nitric acid: perchloric acid: sulfuric acid = 0.3% by mass: 0.5% by mass: 5% by mass: 2% by mass 50 none none Example 20 Ammonium fluoride: nitric acid: sulfuric acid: acetic acid = 0.3% by mass: 2% by mass: 5% by mass: 5% by mass 30 none none Example 21 Ammonium fluoride: nitric acid: sulfuric acid: methanesulfonic acid = 0.3% by mass: 1% by mass: 4% by mass: 1% by mass 35 none none Example 22 Ammonium fluoride: Nitric acid: Ammonium sulfate = 0.55 mass%: 0.5 mass%: 0.5 mass% 45 none none Example 23 Ammonium fluoride: Nitric acid: Ethylene sulfate diamine = 0.2 mass%: 3.0 mass%: 0.5 mass% 40 none none Example 24 Ammonium fluoride: Nitric acid: Perchloric acid: Ethylene sulfate diamine = 0.2 mass%: 5.0 mass%: 1.0 mass%: 0.3 mass% 35 none none Example 25 Ammonium fluoride: Nitric acid: Perchloric acid: Ammonium sulfate = 0.2 mass%: 5.0 mass%: 2.0 mass%: 0.5 mass% 40 none none Comparative Example 1 Hydrofluoric acid salt: Nitric acid = 0.2 mass%: 3 mass% 25 has exist none Comparative Example 2 Ammonia water: Hydrogen peroxide = 5 mass%: 10 mass% * none has exist

 *: 3 layer shape becomes uneven

As apparent from Table 1, by using the etching solution of the present invention, the titanium / aluminum / titanium laminate film formed by the sputtering method could be collectively etched in a short time.

Etching liquid of the present invention does not adversely affect the substrate, and because it is possible to collectively etch a metal laminated film including a layer made of titanium or an alloy containing titanium as a main component and a layer made of aluminum or an alloy containing aluminum as its main component, economical efficiency Especially excellent. In addition, since the control of the taper angle can be easily performed, it is possible to manufacture a high quality product by improving the coating property of the gate electrode. Therefore, the etching liquid of this invention can be used as an etching liquid of a metal laminated film at the time of forming wiring, an electrode, etc. in the manufacturing process of electronic devices, such as a semiconductor device and a liquid crystal display.

Claims (10)

A fluorine compound (except hydrofluoric acid) and an oxidizing agent, which are used to collectively etch a metal laminate film comprising a layer composed of titanium or titanium based alloys and a layer composed of aluminum or aluminum based alloys. Etching liquid composition. The etching solution composition according to claim 1, wherein the fluorine compound is at least one selected from the group consisting of silicic hexafluoride, hydrofluoric acid or silicic hexafluoride, and a metal or ammonia. The method of claim 1, wherein the oxidizing agent is nitrate, ammonium nitrate, ammonium sulfate, ammonium persulfate, potassium persulfate, perchloric acid, ammonium perchlorate, sodium perchlorate, potassium perchlorate, periodic acid, sodium periodate, potassium periodate, The etching liquid composition which is at least 1 type, or 2 or more types chosen from methanesulfonic acid, hydrogen peroxide, sulfuric acid, and ethylenediamine sulfate. The etching liquid composition according to claim 1, wherein the concentration of the fluorine compound is 0.01 to 5% by mass and the concentration of the oxidant is 0.1 to 50% by mass. The etching solution composition of claim 1, wherein the oxidant is nitric acid or methanesulfonic acid. The method of claim 5, wherein the oxidizing agent is ammonium nitrate, ammonium sulfate, ammonium persulfate, potassium persulfate, perchloric acid, ammonium perchlorate, sodium perchlorate, potassium perchlorate, periodic acid, sodium periodate, potassium periodate, hydrogen peroxide , At least one selected from sulfuric acid and ethylenediamine sulfate. The etching liquid composition of Claim 1 which further contains at least 1 sort (s) chosen from amic-sulfuric acid, acetic acid, and hydrochloric acid. The etching liquid composition according to claim 1, wherein the base substrate of the metal laminate film is a glass substrate for liquid crystal display. The etching liquid composition according to claim 1, wherein the base substrate of the metal laminate film is a silicon substrate or a compound semiconductor substrate for a semiconductor device (except for hydrofluoric acid) and an oxidizing agent. The taper angle after etching of the metal laminated film as described in any one of Claims 1-9 containing the layer which consists of titanium or the alloy which has titanium as a main component, and the layer which consists of aluminum or the alloy which has aluminum as a main component, The etching liquid composition used to make it 90 degrees.

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