WO2021134916A1

WO2021134916A1 - Etching solution composition and method for etching copper-molybdenum film layer

Info

Publication number: WO2021134916A1
Application number: PCT/CN2020/078689
Authority: WO
Inventors: 吴豪旭
Original assignee: 深圳市华星光电半导体显示技术有限公司
Priority date: 2020-01-03
Filing date: 2020-03-11
Publication date: 2021-07-08
Also published as: CN111074278A

Abstract

Disclosed are an etching solution composition and a method for etching a copper-molybdenum film layer. The etching solution composition comprises: hydrogen peroxide, a hydrogen peroxide stabilizer, an etching additive, a pH regulator and deionized water.

Description

Etching solution composition and copper-molybdenum film layer etching method

Technical field

This application relates to the field of display technology, in particular to an etching solution composition and a copper-molybdenum film layer etching method.

Background technique

In the current high-generation thin film transistor-liquid crystal display production process, thin film transistors are most commonly used amorphous silicon thin film transistors. In this kind of thin film transistor, if the resistance of the metal trace is too high, the RC-Delay effect is likely to have a greater impact on the display effect, thereby affecting the display effect of the panel. The copper material has a lower resistivity, which can To meet the wiring requirements of large-size panels, the copper/molybdenum film layer has become the main gate, source and drain metal layer structure of this type of thin film transistor. Therefore, the development of the corresponding etching solution is also particularly important.

At present, the popular copper/molybdenum etching solutions on the market basically contain fluoride. On the one hand, it is not conducive to the health of the operators. On the other hand, due to its strong corrosive ability, it often causes corrosion of the glass substrate. As a result, the reliability of the display panel is affected, and the waste water generated by etching will contain a large amount of fluoride, resulting in higher waste liquid treatment costs.

technical problem

The present application provides an etching solution composition and a copper-molybdenum film layer etching method. The etching solution composition does not contain fluoride and can meet the current conventional copper/molybdenum film etching requirements.

Technical solutions

In a first aspect, the present invention provides an etching solution composition, the etching solution composition comprising: hydrogen peroxide, hydrogen peroxide stabilizer, etching additive, pH adjuster, and deionized water.

In the etching solution composition provided by the embodiment of the present application, the content of the hydrogen peroxide is 4-10wt%, the content of the hydrogen peroxide stabilizer is 0.1-5wt%, and the content of the etching additive is 5 -35wt%, the content of the pH adjuster is 0.2-5wt%, and the remaining content is deionized water.

In the etching solution composition provided by the embodiment of the present application, the etching solution composition further includes an inorganic acid, and the content of the inorganic acid is 0.1-4 wt%.

In the etching solution composition provided by the embodiment of the present application, the inorganic acid is selected from at least one of phosphoric acid, nitric acid, and sulfuric acid.

In the etching solution composition provided by the embodiment of the present application, the hydrogen peroxide stabilizer is selected from N-phenylurea, N,N'-diphenylurea, 1,3-diethyl-1,3 -At least one of diphenylurea, 4-methylthiosemicarbazide and diphenylsemicarbazide.

In the etching solution composition provided by the embodiment of the present application, the etching additive includes at least one organic acid and at least one alcohol amine compound.

In the etching solution composition provided by the embodiment of the present application, the organic acid is selected from tartaric acid, malonic acid, benzoic acid, diglycolic acid, maleic acid, hydroxybutyric acid, lactic acid, malic acid, and succinic acid.

In the etching solution composition provided by the embodiment of the present application, the alcohol amine compound is selected from isopropanolamine, diethanolamine, triisopropanolamine, and monoethanolamine.

In the etching solution composition provided by the embodiment of the present application, the pH adjusting agent is selected from at least one of phosphate or hydrogen phosphate.

In the etching solution composition provided by the embodiment of the present application, the pH adjusting agent is selected from at least one of ammonium phosphate, diammonium hydrogen phosphate, potassium dihydrogen phosphate, and diammonium hydrogen phosphate.

In the etching solution composition provided by the embodiment of the present application, the pH adjusting agent makes the pH value of the etching solution composition control at 3-6.

On the other hand, the present invention also provides a copper-molybdenum film layer etching method, which uses the aforementioned etching solution composition to wet-etch the copper-molybdenum film layer.

In the copper-molybdenum film layer etching method provided by the embodiment of the present application, the thickness of the copper-molybdenum film layer is 2000-8000 angstroms.

In the copper-molybdenum film layer etching method provided in the embodiment of the present application, during the etching process, the temperature of the etching solution composition is 30-40°C.

Beneficial effect

Compared with the prior art, the present invention provides an etching solution composition that does not contain fluoride and has simple components. On the one hand, it is friendly to production line operators and the environment, and the etching waste liquid treatment The cost is greatly reduced. On the other hand, it can meet the current conventional copper/molybdenum film etching requirements. The etching process is stable, the etching rate is moderate, the etching angle is low, and the etching angle is stable at 20~45°, and it will not cause corrosion to the glass substrate. .

Description of the drawings

In order to explain the technical solutions in the embodiments of the present invention more clearly, the following will briefly introduce the drawings needed in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

1 is a schematic diagram of a cross-sectional morphology of a film formed after etching a copper-molybdenum film layer by an etching solution composition according to an embodiment of the present invention;

2 is a schematic diagram of a cross-sectional morphology of a copper-molybdenum film formed by etching another etching solution composition according to an embodiment of the present invention.

Embodiments of the present invention

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the protection scope of the present invention.

In the following description, the details are listed for the purpose of explanation. It should be understood that those of ordinary skill in the art can realize that the present invention can also be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid unnecessary details to obscure the description of the present invention. Therefore, the present invention is not intended to be limited to the illustrated embodiments, but is consistent with the widest scope that conforms to the principles and features disclosed in this application.

An embodiment of the present invention provides an etching solution composition, the etching solution composition comprising: hydrogen peroxide, hydrogen peroxide stabilizer, etching additive, pH regulator, and deionized water.

In some embodiments, the content of the hydrogen peroxide is 4-10 wt%, and further, the content of the hydrogen peroxide is 5-9 wt%;

The content of the hydrogen peroxide stabilizer is 0.1-5wt%, and further, the content of the hydrogen peroxide stabilizer is 0.5-2wt%;

The content of the etching additive is 5-35wt%, and further, the content of the etching additive is 10-25wt%;

The content of the pH regulator is 0.2-5wt%, and further, the content of the pH regulator is 0.2-2wt%;

Among other substances, the remaining content is deionized water.

In some embodiments, the etching solution composition further includes an inorganic acid, and the content of the inorganic acid is 0.1-4 wt%, and further, the content of the inorganic acid is 0.5-2 wt%.

In some embodiments, the inorganic acid may generally be phosphoric acid, nitric acid or sulfuric acid. The inorganic acid has an oxidizing effect and can oxidize molybdenum to a high valence state, making it easier for molybdenum to be chelated, thereby avoiding molybdenum residues after etching. This leads to the occurrence of related defects of the display panel.

In some embodiments, the hydrogen peroxide stabilizer is selected from N-phenylurea, N,N'-diphenylurea, 1,3-diethyl-1,3-diphenylurea, 4- At least one of methyl thiosemicarbazide and diphenyl semicarbazide. The hydrogen peroxide stabilizer can prevent the violent chain reaction of hydrogen peroxide, and prevent the hydrogen peroxide ions from the excessive decomposition of hydrogen peroxide, so that the hydrogen peroxide can function smoothly and fully.

In some embodiments, the etching additives include at least one organic acid and at least one alcohol amine compound. The etching additives can effectively control the etching rate of the etching solution, contribute to the stable etching of copper and molybdenum, and remove residues derived from molybdenum to obtain a good wiring cross-sectional shape.

In some embodiments, the organic acid is selected from tartaric acid, malonic acid, benzoic acid, diglycolic acid, maleic acid, hydroxybutyric acid, lactic acid, malic acid and succinic acid, and the alcohol amine compound is selected from Isopropanolamine, diethanolamine, triisopropanolamine, monoethanolamine.

In some embodiments, the pH adjusting agent is selected from at least one of phosphate or hydrogen phosphate. Specifically, the pH adjusting agent may be selected from ammonium phosphate, diammonium hydrogen phosphate, potassium dihydrogen phosphate, and At least one of diammonium hydrogen phosphate.

In some embodiments, the pH adjuster makes the pH value of the etching solution composition controlled at 3-6, and further, the pH value of the etching solution composition is controlled at 4.5-5.5, which is too low pH It will cause excessive acidity, which will damage other film layers during the etching process. Excessive pH will cause the decomposition of hydrogen peroxide, which is not conducive to the smooth progress of the reaction.

The etching solution composition provided by the present invention does not contain the fluoride present in the traditional etching solution, the etching process is stable, the etching rate is moderate, the etching angle is low, and it will not damage the substrate glass, and its hydrogen peroxide content is extremely low. , No high-risk chemicals, low cost, convenient for industrial application.

In another embodiment of the present invention, there is also provided a copper-molybdenum film layer etching method, using the aforementioned etching solution composition to treat the copper-molybdenum film layer (ie a stacked film layer of a copper film layer and a molybdenum film layer) Perform wet etching.

In some embodiments, the thickness of the copper-molybdenum film layer is 2000-8000 angstroms.

In some embodiments, during the etching process, the temperature of the etchant composition is 30-40°C.

A number of examples are listed below to further illustrate the implementation of the present invention:

Example 1

An etching solution composition comprising the following components by weight percentage: hydrogen peroxide 5.3wt%, N-phenylurea 0.8wt%, tartaric acid 8wt%, isopropanolamine 6.5wt%, diammonium hydrogen phosphate 0.4wt%, deionized water 79wt%, the pH of the etching solution composition is 4.9.

Example 2

An etching solution composition comprising the following components by weight percentage: hydrogen peroxide 8.6wt%, N,N'-diphenylurea 0.8wt%, benzoic acid 5.5wt%, triisopropanolamine 5wt% %, ammonium phosphate 0.4wt%, phosphoric acid 1.2wt%, deionized water 78.1wt%, and the pH of the etching solution composition is 4.9.

In order to verify the etching effect of the etching solution composition provided in the foregoing embodiment, the following operations are performed:

A copper-molybdenum laminate film layer is formed on the substrate, specifically, a 300 angstrom molybdenum film layer is formed on the substrate, and then a 7000 angstrom copper film layer is formed on the molybdenum film layer, and then the copper-molybdenum laminate film Coat a layer of photoresist on the layer, expose and develop the photoresist to form a specific shape, and then use the etching solution composition provided in Example 1 to perform wet etching. The temperature of the etching solution composition during the etching process is Maintain a constant temperature of 35°C. After the etching is completed, take a random spot of the etched film and observe the cross-sectional shape under a scanning electron microscope. See Figure 1 for the formation of the microscopic topography. It can be seen from the figure that the film is complete after etching and the formed The etched cone angle has a good shape, the angle is 41.9°, and the smaller slope is conducive to the stacking of the upper layer. Compared with the over-etching size of the upper layer photoresist, which is 0.8295um, it meets the conventional control standards for this size (usually 0.6-1.2um) ), and there is no molybdenum residue after etching.

Similarly, using the above steps to verify the etching effect of the etching solution composition provided in Example 2, please refer to Figure 2 for the obtained cross-sectional morphology after etching. It can be seen from the figure that the film layer after etching is complete and the formed etching The cone angle has a good shape, the angle is 38.7°, and the small slope is conducive to the stacking of the upper layer. Compared with the over-etching size of the upper layer photoresist, which is 0.8830um, it meets the conventional control standards for this size (usually 0.6-1.2um) At the same time, there is no molybdenum residue after etching.

In the above-mentioned embodiments, the description of each embodiment has its own focus. For a part that is not described in detail in an embodiment, please refer to the detailed description of other embodiments above, which will not be repeated here.

The above describes in detail an etching solution composition and a copper-molybdenum film etching method provided by the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementations of the present invention. The description of the above embodiments It is only used to help understand the method and the core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and the scope of application. In summary, this The contents of the description should not be construed as limiting the present invention.

Claims

An etching solution composition, wherein the etching solution composition includes: hydrogen peroxide, hydrogen peroxide stabilizer, etching additive, pH regulator and deionized water.
The etching solution composition of claim 1, wherein the content of the hydrogen peroxide is 4-10 wt%, the content of the hydrogen peroxide stabilizer is 0.1-5 wt%, and the content of the etching additive is 5 -35wt%, the content of the pH adjuster is 0.2-5wt%, and the remaining content is deionized water.
3. The etching solution composition of claim 2, wherein the etching solution composition further comprises an inorganic acid, and the content of the inorganic acid is 0.1-4 wt%.
The etching solution composition of claim 3, wherein the inorganic acid is at least one selected from phosphoric acid, nitric acid, and sulfuric acid.
The etching solution composition of claim 1, wherein the hydrogen peroxide stabilizer is selected from the group consisting of N-phenylurea, N,N'-diphenylurea, 1,3-diethyl-1,3 -At least one of diphenylurea, 4-methylthiosemicarbazide and diphenylsemicarbazide.
8. The etching solution composition of claim 1, wherein the etching additive comprises at least one organic acid and at least one alcohol amine compound.
The etching solution composition of claim 6, wherein the organic acid is selected from the group consisting of tartaric acid, malonic acid, benzoic acid, diglycolic acid, maleic acid, hydroxybutyric acid, lactic acid, malic acid and succinic acid.
8. The etching solution composition of claim 6, wherein the alcohol amine compound is selected from the group consisting of isopropanolamine, diethanolamine, triisopropanolamine, and monoethanolamine.
The etching solution composition of claim 1, wherein the pH adjusting agent is selected from at least one of phosphate and hydrogen phosphate.
The etching solution composition of claim 9, wherein the pH adjusting agent is selected from at least one of ammonium phosphate, diammonium hydrogen phosphate, potassium dihydrogen phosphate, and diammonium hydrogen phosphate.
8. The etching solution composition of claim 1, wherein the pH adjusting agent makes the pH value of the etching solution composition control 3-6.
A copper-molybdenum film layer etching method, wherein the copper-molybdenum film layer is wet-etched using the etching solution composition of claim 1.
13. The copper-molybdenum film layer etching method of claim 12, wherein the thickness of the copper-molybdenum film layer is 2000-8000 angstroms.
The method for etching a copper-molybdenum film layer according to claim 12, wherein, during the etching process, the temperature of the etching solution composition is 30-40°C.