CN110846663A

CN110846663A - Etching solution composition and method for forming metal circuit

Info

Publication number: CN110846663A
Application number: CN201911110338.1A
Authority: CN
Inventors: 秦文
Original assignee: TCL Huaxing Photoelectric Technology Co Ltd
Current assignee: TCL China Star Optoelectronics Technology Co Ltd; TCL Huaxing Photoelectric Technology Co Ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-02-28

Abstract

An etching solution composition and a method for forming a metal circuit, wherein the etching solution composition comprises 10-20 wt% of hydrogen peroxide; 4-13 wt% of an organic acid; 1-5 wt% hydrogen peroxide stabilizer; 2-10% by weight of an organic base; 0.001 to 1 wt% of a corrosion inhibitor; 2-5 wt% of a PH buffer; and 47-80 wt% deionized water; the method uses the etching solution composition to etch the copper-containing metal film so as to pattern the copper-containing metal film and form the metal circuit.

Description

Etching solution composition and method for forming metal circuit

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of display panels, in particular to an etching solution composition and a method for forming a metal circuit.

[ background of the invention ]

Copper lines used for gate and data metal lines of large displays have an advantage of low impedance compared to aluminum lines in the prior art, but copper has poor adhesion to glass substrates, and therefore molybdenum or molybdenum alloys are generally used as transition layers.

The copper/molybdenum metal structure widely used in the industry is prone to cause an undercut (undercut) phenomenon due to galvanic corrosion (galvanic corrosion) in the etching process, and the undercut phenomenon may cause light leakage to affect the contrast and generate problems such as electrical offset of a Thin Film Transistor (TFT), which affect the display effect. However, the titanium in the molybdenum-titanium alloy has a passivation effect, so that the relative etching rate is relatively consistent, and undercuts are less prone to be generated, and the display effect of the display can be improved.

At present, because the molybdenum titanium layer is difficult to etch, the used etching solution basically contains fluoride, although the fluoride has a certain beneficial effect on removing the molybdenum layer residue in the etching process, the fluoride can react with the substrate glass to generate fluoride ions (F)^-) With silicon dioxide (SiO)₂) Chemical reaction occurs, so that the substrate glass is damaged, the back-end process is influenced, and the fluoride belongs to an environment-friendly substance, thereby causing adverse effect on the health of personnel and improving the treatment cost of wastewater.

[ summary of the invention ]

In order to solve the problems of the prior fluorine-containing etching solution composition, the invention provides an etching solution composition, which comprises 10-20 wt% of hydrogen peroxide; 4-13 wt% of an organic acid; 1-5 wt% hydrogen peroxide stabilizer; 2-10% by weight of an organic base; 0.001 to 1 wt% of a corrosion inhibitor; 2-5 wt% of a PH buffer; and 47-80 wt% deionized water.

In the etching solution composition of the present invention, the hydrogen peroxide serves as a main oxidizing agent for the copper-molybdenum alloy. When the amount of the hydrogen peroxide is less than 10 wt% based on the total weight of the etching solution composition, the molybdenum alloy is insufficiently oxidized, and etching cannot be performed; when the amount exceeds 20% by weight, the etching rate is too high, and it is difficult to control the progress of the process.

Preferably, the organic acid is selected from the group consisting of: succinic acid, malic acid, glycolic acid, citric acid, phthalic acid, salicylic acid, alanine, asparagine, arginine.

In the etching solution composition, the organic acid is used for regulating the etching rate of the etching solution, is beneficial to etching copper and molybdenum titanium, and is coordinated with the pH regulator to control the pH value so as to remove molybdenum titanium residues and ensure the etching effect.

Preferably, the hydrogen peroxide stabilizer is selected from the group consisting of: n-phenylurea, 1, 3-diethyl-1, 3-diphenylurea, 4-methylthiosemicarbazide, diphenylsemicarbazide.

In the etching solution composition, the hydrogen peroxide stabilizer is used for preventing violent chain reaction of hydrogen peroxide and avoiding quick decomposition of the hydrogen peroxide, so that the hydrogen peroxide can play a role stably and fully.

Preferably, the corrosion inhibitor is selected from the group consisting of: 6-nitrobenzimidazole, 2-aminothiazole, 2-amino-5-nitrothiazole, 5-aminotetrazole, 3-amino-1, 2, 4-triazole, benzotriazole, sodium triazole and mercaptobenzotriazole.

In the etching solution composition, the etching corrosion inhibitor is mainly used for adjusting the etching rate and enabling the reaction to be carried out stably, thereby improving the etching uniformity.

Preferably, the PH buffer is selected from the group consisting of: phosphate, hydrogen phosphate, hypophosphite.

Preferably, the pH buffer controls the pH value of the etching solution composition to be 3-6.

In the etching solution composition, the pH buffer agent controls the pH range of the etching solution composition to be 3-6, the moderate acidity can stabilize the decomposition of hydrogen peroxide, and simultaneously, the etching rates of copper and a molybdenum-titanium metal film layer are matched, so that a pattern with a good wiring shape is obtained.

Preferably, the phosphate is ammonium phosphate, the hydrogen phosphate is diammonium hydrogen phosphate, and the hypophosphite is ammonium dihydrogen phosphate or potassium dihydrogen phosphate.

Preferably, the organic base is selected from the group consisting of: diisopropanolamine, polyacrylamide, m-phenylenediamine, p-chloroaniline, isopropanolamine and 2-amino-2-methyl-1-propanol.

In the etching solution composition of the present invention, the organic base is used as an etching shape control agent in addition to PH adjustment, and is mainly used for adjusting an etching angle.

The invention also provides a method for forming a metal circuit of a display, which comprises the step of etching the copper-containing metal film by using the etching solution composition to pattern the copper-containing metal film to form the metal circuit.

Preferably, the etching solution composition is used to etch the copper-containing metal film at 30-35 ℃, wherein the copper-containing metal film comprises the following group: molybdenum titanium/copper/molybdenum titanium (MoTi/Cu/MoTi) and copper/molybdenum titanium (Cu/MoTi).

The invention focuses on the development of the fluoride-free environment-friendly etching solution, can obtain a good wiring structure, has stable etching process and moderate etching rate, and cannot damage the substrate glass.

[ description of the drawings ]

FIG. 1 is a schematic view illustrating a display panel of the present embodiment entering an etching tool;

FIG. 2a is a schematic cross-sectional view of a display panel of the present embodiment;

FIG. 2b is a schematic cross-sectional view of the display panel of this embodiment after exposure and development;

FIG. 2c is a schematic cross-sectional view of the display panel of the present embodiment after etching;

FIG. 3 is a schematic view illustrating the display panel of the present embodiment entering an etching tool;

FIGS. 4a and 4b are cross-sectional and top-view photographs of a test piece observed by a scanning electron microscope after etching a copper-molybdenum-titanium alloy film layer with the etchant composition according to an embodiment of the present invention; and

fig. 5a and 5b are cross-sectional and top-view photographs of a test piece observed by a scanning electron microscope after etching a molybdenum-titanium alloy, copper, or molybdenum-titanium alloy film layer with the etchant composition according to the embodiment of the present invention.

[ detailed description ] embodiments

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Example one

FIG. 1 is a schematic diagram illustrating the display panel 10 of the present embodiment entering an etching machine 50, wherein the etching temperature of the etching machine 50 is set to 32 ℃ and the plate speed is 2 m/min;

fig. 2a is a schematic cross-sectional view of the display panel 10 of the present embodiment, which includes a glass substrate 100, a copper/molybdenum titanium (Cu/MoTi) alloy film 200 coated on the glass substrate 100, and a photoresist layer 300 coated on the copper/molybdenum titanium (Cu/MoTi) alloy film 200, wherein after exposure through a mask and development with a developer, as shown in fig. 2b, the area not covered by the photoresist layer 300 is the area to be etched.

The etching solution composition used had a pH of 4.7 and the contents were as shown in the following Table one:

watch 1

Fig. 3 is a schematic diagram illustrating the discharging of the display panel 10 after the etching process is performed by the etching machine 50, at this time, the copper/molybdenum titanium (Cu/MoTi) alloy film layer 200 of the display panel 10 has been etched to form a desired pattern, and as shown in fig. 2c, the copper/molybdenum titanium (Cu/MoTi) alloy film layer 200 not covered by the photoresist layer 300 has been etched and removed.

FIGS. 4a and 4b show the cross section and plan view of a test piece observed by a scanning electron microscope after etching a Cu/Mo-Ti alloy film and before stripping, respectively, using the etchant composition of this example, and it is clear that the etching performance is good, no undercut (undercut) occurs, and the glass surface of the substrate is not damaged.

Example two

FIG. 1 is a schematic diagram illustrating the display panel 10 of the present embodiment entering an etching machine 50, wherein the etching temperature of the etching machine 50 is set to 34 ℃ and the plate speed is 1.8 m/min;

fig. 2a is a schematic cross-sectional view of the display panel 10 of the present embodiment, which includes a glass substrate 100, a molybdenum titanium/copper/molybdenum titanium (MoTi/Cu/MoTi) alloy film 200 coated on the glass substrate 100, and a photoresist layer 300 coated on the molybdenum titanium/copper/molybdenum titanium (MoTi/Cu/MoTi) alloy film 200, wherein after exposure through a mask and development with a developer, as shown in fig. 2b, a region not covered by the photoresist layer 300 is a region to be etched.

The etching solution composition used had a pH of 5.8 and the contents were as shown in Table II below:

watch two

Fig. 3 is a schematic diagram illustrating a discharging process of the display panel 10 after the display panel 10 is etched by the etching machine 50, where the mo-ti/Cu/mo-ti (MoTi/Cu/MoTi) alloy film 200 of the display panel 10 is etched to form a desired pattern, and as shown in fig. 2c, the mo-ti/Cu/MoTi (MoTi/Cu/MoTi) alloy film 200 not covered by the photoresist layer 300 is etched and removed.

Fig. 5a and 5b show the cross section and plan view of the test piece observed by using a scanning electron microscope after the mo-ti/cu-mo-ti alloy film is etched and before the film is stripped using the etchant composition of the present example, respectively, and it is clear that the etching performance is good, no undercut (undercut) occurs, and the glass surface of the substrate is not damaged.

The invention provides the fluorine-free copper/molybdenum titanium etching solution composition which is environment-friendly, can obtain a wiring structure with a good shape, has stable etching process and moderate etching rate, and cannot generate chemical reaction with substrate glass to damage the substrate glass. In order to be compatible with different film structure designs, the invention has good etching performance on both MoTi/Cu/MoTi structures and Cu/MoTi structures.

In summary, although the present invention has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so that the scope of the present invention shall be determined by the appended claims.

Claims

1. An etching solution composition, comprising:

10-20% by weight of hydrogen peroxide;

4-13 wt% of an organic acid;

1-5 wt% hydrogen peroxide stabilizer;

2-10% by weight of an organic base;

0.001 to 1 wt% of a corrosion inhibitor;

2-5 wt% of a PH buffer; and

47-80% by weight of deionized water.

2. The etching solution composition as claimed in claim 1, wherein the organic acid is selected from the group consisting of: succinic acid, malic acid, glycolic acid, citric acid, phthalic acid, salicylic acid, alanine, asparagine, and arginine.

3. The etching solution composition as claimed in claim 1, wherein the hydrogen peroxide stabilizer is selected from the group consisting of: n-phenylurea, 1, 3-diethyl-1, 3-diphenylurea, 4-methylthiosemicarbazide, and diphenylsemicarbazide.

4. The etching solution composition as claimed in claim 1, wherein the corrosion inhibitor is selected from the group consisting of: 6-nitrobenzimidazole, 2-aminothiazole, 2-amino-5-nitrothiazole, 5-aminotetrazole, 3-amino-1, 2, 4-triazole, benzotriazole, sodium triazole and mercaptobenzotriazole.

5. The etchant composition of claim 1, wherein the PH buffer is selected from the group consisting of: phosphates, hydrogenphosphates, and hypophosphites.

6. The etching solution composition as claimed in claim 5, wherein the pH buffer controls the pH of the etching solution composition to be 3 to 6.

7. The etching solution composition according to claim 5, wherein the phosphate is ammonium phosphate, the hydrogen phosphate is diamine hydrogen phosphate, and the hypophosphite is ammonium dihydrogen phosphate or potassium dihydrogen phosphate.

8. The etching solution composition as claimed in claim 1, wherein the organic base is selected from the group consisting of: diisopropanolamine, polyacrylamide, m-phenylenediamine, p-chloroaniline, isopropanolamine, and 2-amino-2-methyl-1-propanol.

9. A method for forming a metal wiring, comprising etching a copper-containing metal thin film using the etchant composition of claim 1 to pattern the copper-containing metal thin film to form the metal wiring.

10. The method of claim 9, wherein the copper-containing metal film is etched using the etchant composition at a temperature of 30-35 ℃, wherein the copper-containing metal film comprises a group consisting of: molybdenum titanium/copper/molybdenum titanium and copper/molybdenum titanium.