CN113278975A

CN113278975A - Copper-molybdenum etchant composition, etching method of copper-molybdenum film and display panel

Info

Publication number: CN113278975A
Application number: CN202110507286.2A
Authority: CN
Inventors: 何毅烽
Original assignee: TCL China Star Optoelectronics Technology Co Ltd
Current assignee: TCL China Star Optoelectronics Technology Co Ltd
Priority date: 2021-05-10
Filing date: 2021-05-10
Publication date: 2021-08-20

Abstract

The invention provides a copper-molybdenum etchant composition, an etching method of a copper-molybdenum film layer and a display panel, wherein the copper-molybdenum etchant composition comprises the following components in parts by weight: the copper-molybdenum etching agent composition comprises hydrogen peroxide, water and an etching auxiliary agent, wherein the etching auxiliary agent accounts for 4 wt% -20 wt% of the copper-molybdenum etching agent composition by mass, and the etching auxiliary agent comprises a hydrogen peroxide stabilizer, an etching inhibitor, an etching additive and a pH regulator. In the copper-molybdenum etchant, except for the necessary etching components of hydrogen peroxide and water, the content of other added etching auxiliary agents is low, so that the production and manufacturing cost is greatly reduced, and meanwhile, the copper-molybdenum etchant still has good etching performance, can effectively avoid the occurrence of poor molybdenum residue and has longer service life.

Description

Copper-molybdenum etchant composition, etching method of copper-molybdenum film and display panel

Technical Field

The application relates to the technical field of display, in particular to a copper-molybdenum etchant composition, an etching method of a copper-molybdenum film layer and a display panel.

Background

In the production process of advanced liquid crystal displays, copper/molybdenum film wiring is generally used instead of aluminum film wiring in order to reduce impedance and improve electrical characteristics. Copper metal is much less reactive (reducing) than aluminum and therefore is much more difficult to etch than aluminum. Compared with the simple combination of an aluminum etchant as an oxidant and acid (nitric acid + acetic acid + phosphoric acid), the copper-molybdenum etchant is complex in composition, the components of the copper-molybdenum etchant are in proper proportion, and the material and etching characteristics can meet the specification. Due to the complex composition, the copper-molybdenum etchant always encounters various problems in the development process, such as molybdenum residue, low cutting, hollowing and other morphological defects and low service life.

At present, in order to increase on-state current and reduce off-state current, the narrower the channel between the source electrode and the drain electrode in the source and drain metal layers of the thin film transistor is within an allowable range, the better the channel is, that is, the line width of the copper/molybdenum film layer needs to be as long as possible. Under such conditions, the etching time of the copper/molybdenum film layer by the copper etchant is reduced, so that molybdenum residue is easily caused. The existence of molybdenum residue is likely to cause problems such as short circuit between electrodes or abnormal discharge, and therefore, a higher requirement is put on the etching performance of the copper-molybdenum etchant, and here, the molybdenum residue is referred to fig. 1, and compared with the surface morphology of the copper-molybdenum etchant shown in fig. 2, which does not have the molybdenum residue after etching, it can be observed that in the region without the copper-molybdenum film, a pockmark-like foreign matter exists on the surface, that is, the residue is caused by incomplete etching of the bottom molybdenum film. In addition, a large amount of etchant is consumed in the wet etching process, and the etching characteristics of the etchant are changed to waste liquid when the etchant reaches the end of the service life, so that it is important to increase the service life of the copper molybdenum etchant in terms of cost effectiveness or environmental protection. According to research and discovery, the market can consider the condition of good molybdenum residue, and the copper etchant with low additive content and long service life is few, so the development of the copper etchant for improving the molybdenum residue, low additive and long service life is significant.

Disclosure of Invention

The invention provides a copper-molybdenum etchant composition, an etching method of a copper-molybdenum film layer and a display panel.

In order to solve the above problems, in a first aspect, the present invention provides a copper molybdenum etchant composition comprising: the copper-molybdenum etching agent composition comprises hydrogen peroxide, water and an etching auxiliary agent, wherein the etching auxiliary agent accounts for 4 wt% -20 wt% of the copper-molybdenum etching agent composition by mass, and the etching auxiliary agent comprises a hydrogen peroxide stabilizer, an etching inhibitor, an etching additive and a pH regulator.

In the copper-molybdenum etchant composition provided by the embodiment of the invention, the hydrogen peroxide is 10 wt% -20 wt%, the hydrogen peroxide stabilizer is 0.1 wt% -2 wt%, the etching inhibitor is 0.1 wt% -1 wt%, the etching additive is 2 wt% -10 wt%, and the pH regulator is 0.1 wt% -5 wt%.

In the copper-molybdenum etchant composition provided by the embodiment of the invention, the hydrogen peroxide stabilizer is at least one selected from urea compounds, phosphate salts or alcohol compounds.

In the copper-molybdenum etchant composition provided by the embodiment of the invention, the etching inhibitor is at least one selected from azole compounds, thiophene compounds, indole compounds, purine compounds, pyrimidine compounds and pyrrole compounds.

In the copper-molybdenum etchant composition provided by the embodiment of the invention, the etching additive is selected from at least two of amine compounds, organic acids and inorganic acids.

In the copper-molybdenum etchant composition provided by the embodiment of the invention, the pH regulator is at least one selected from inorganic acid or inorganic base.

In the copper-molybdenum etchant composition provided by the embodiment of the invention, the pH value of the copper-molybdenum etchant composition is 2-4.

In a second aspect, the present invention further provides an etching method for a copper molybdenum film layer, where the etching method includes the following steps:

providing a substrate, and forming a copper molybdenum film layer on the substrate;

forming a light resistance layer on the copper molybdenum film layer;

etching the copper-molybdenum film layer by using the copper-molybdenum etchant composition under the shielding of the photoresist layer; and

and stripping off the photoresist layer.

In the etching method of the copper-molybdenum film layer provided by the embodiment of the invention, the temperature of the copper-molybdenum etchant composition is 30-35 ℃.

In a third aspect, the present invention further provides a display panel, where the display panel includes a metal layer, and the metal layer is formed by etching the copper molybdenum film layer by the etching method.

Has the advantages that: the invention provides a copper-molybdenum etchant composition, an etching method of a copper-molybdenum film layer and a display panel, wherein the copper-molybdenum etchant composition comprises the following components in parts by weight: the copper-molybdenum etching agent composition comprises hydrogen peroxide, water and an etching auxiliary agent, wherein the etching auxiliary agent accounts for 4 wt% -20 wt% of the copper-molybdenum etching agent composition by mass, and the etching auxiliary agent comprises a hydrogen peroxide stabilizer, an etching inhibitor, an etching additive and a pH regulator. In the copper-molybdenum etchant, except for the necessary etching components of hydrogen peroxide and water, the content of other added etching auxiliary agents is low, so that the production and manufacturing cost is greatly reduced, and meanwhile, the copper-molybdenum etchant still has good etching performance, can effectively avoid the occurrence of poor molybdenum residue and has longer service life.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a surface topography of a copper molybdenum film layer characterized by a scanning electron microscope after etching to generate molybdenum residue according to the prior art;

fig. 2 is a surface topography map of a copper molybdenum film layer characterized by a scanning electron microscope without molybdenum residue after etching according to the prior art.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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 invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In this application, the word "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the invention. In the following description, details are set forth for the purpose of explanation. It will be apparent to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known structures and processes are not shown in detail to avoid obscuring the description of the invention with unnecessary detail. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

The embodiment of the invention provides a copper-molybdenum etchant composition, which comprises the following components in part by weight: the copper-molybdenum etching agent composition comprises hydrogen peroxide, water and an etching auxiliary agent, wherein the etching auxiliary agent accounts for 4 wt% -20 wt% of the copper-molybdenum etching agent composition by mass, and the etching auxiliary agent comprises a hydrogen peroxide stabilizer, an etching inhibitor, an etching additive and a pH regulator.

In the copper molybdenum etchant provided by the embodiment, except for the necessary etching components of hydrogen peroxide and water, the content of other added etching auxiliary agents is low, so that the production and manufacturing cost is greatly reduced, and meanwhile, the copper molybdenum etchant still has good etching performance, can effectively avoid the occurrence of poor molybdenum residue, and has a long service life.

Further preferably, in the copper-molybdenum etchant composition, the etching assistant is present in an amount of 4 wt% to 10 wt%, for example, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, or 9 wt%.

In some embodiments, the weight percentage of hydrogen peroxide in the copper molybdenum etchant composition is 10 wt% to 20 wt%, and may be, for example, 12 wt%, 14 wt%, 16 wt%, or 18 wt%;

the hydrogen peroxide stabilizer is 0.1 wt% to 2 wt%, preferably 0.1 wt% to 1 wt%, for example, 0.2 wt%, 0.4 wt%, 0.6 wt% or 0.8 wt%;

the mass percentage of the etching inhibitor is 0.1 wt% to 1 wt%, preferably, the mass percentage of the etching inhibitor is 0.1 wt% to 0.6 wt%, for example, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt% or 0.6 wt%;

the etching additive accounts for 2 wt% to 10 wt%, preferably 4 wt% to 8 wt%, for example, 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt% or 7 wt%;

the content of the pH regulator is 0.1 wt% to 5 wt%, and preferably, the content of the etching additive is 0.5 wt% to 3 wt%, for example, may be 1 wt%, 1.5 wt%, 2 wt%, or 2.5 wt%.

In some embodiments, the hydrogen peroxide stabilizer is selected from at least one of a urea compound, such as, for example, a phosphate salt, or an alcohol compound, such as, for example, ethylene glycol, illustratively, the urea compound may be N-phenyl urea, 4-methylthiosemicarbazide, diphenylsemicarbazide, and the alcohol compound may be ethylene glycol. The hydrogen peroxide stabilizer can inhibit hydrogen peroxide from being rapidly decomposed, so that the hydrogen peroxide can be stably and fully exerted, meanwhile, the hydrogen peroxide can be combined with free radicals generated by the hydrogen peroxide, the hydrogen peroxide can be protected through the action of hydrogen bonds, and the hydrogen peroxide can be attached to the surface of a copper-molybdenum film layer so that etching is stably carried out.

In some embodiments, the etching inhibitor is selected from at least one of azole compounds, thiophene compounds, indole compounds, purine compounds, pyrimidine compounds, and pyrrole compounds, preferably, the etching inhibitor is selected from azole compounds, such as benzotriazole, 5-amino tetrazole, aminotetrazole, and the like, and the etching inhibitor is used for adjusting an etching rate, maintaining etching stability, and thereby improving uniformity of etching.

In some embodiments, the etching additive is selected from at least two of amine compounds, organic acids and inorganic acids, for example, the amine compounds may be isopropanolamine, ethanolamine, triethylamine, N-ethylethanolamine, etc., the organic acids may be malonic acid, succinic acid, tartaric acid, sulfanilic acid, sulfamic acid, succinic acid, malic acid, benzoic acid, citric acid, sulfosalicylic acid, alanine salicylate, glycine, arginine, iminodiacetic acid, etc., and the inorganic acids may be boric acid, hydrofluoric acid, phosphoric acid, etc., and the etching additive has various effects, namely, the proportion thereof is adjusted to adjust the Taper (Taper angle) after etching; secondly, the etching rate of the etching solution can be effectively regulated and controlled, and the etching of copper and molybdenum is promoted; thirdly, the molybdenum residue can be removed by controlling the pH value under the coordination of the pH regulator, thereby ensuring the etching effect.

In some embodiments, the pH adjuster is selected from at least one of inorganic acid or inorganic base, and may be selected from sodium hydroxide, potassium hydroxide, ammonia water, sulfuric acid, nitric acid, and hydrochloric acid, for example, and by controlling the pH of the copper molybdenum etchant to be 2 to 4, the moderate acidity may stabilize the decomposition of hydrogen peroxide, and simultaneously, the etching rates of copper and molybdenum metal film layers are matched, resulting in a pattern with good wiring shape.

Another embodiment of the present invention further provides an etching method of a copper molybdenum film layer, including the following steps:

providing a substrate, and forming a copper-molybdenum film layer on the substrate, wherein the copper-molybdenum film layer is a film layer structure formed by stacking a molybdenum film layer and a copper film layer and is generally formed by sequential sputtering through a physical vapor deposition process;

forming a light resistance layer on the copper molybdenum film layer;

etching the copper molybdenum film layer by using the copper molybdenum etchant composition provided by the previous embodiment under the shielding of the photoresist layer, and etching to remove the part which is not shielded by the photoresist layer so as to form a predetermined pattern; and

and stripping off the photoresist layer.

Here, with the copper molybdenum etchant composition provided in the foregoing embodiment, because the etching components, other than hydrogen peroxide and water, are less in the content of the etching auxiliary agent added, the production cost is greatly reduced, and meanwhile, the copper molybdenum etchant still has good etching performance, can effectively avoid the occurrence of molybdenum residue, and has a long service life, and avoids the need of frequently switching the etchant in the etching process, thereby increasing the etching efficiency.

In some embodiments, the temperature of the copper molybdenum etchant composition is 30-35 ℃.

Specific examples are given below for further illustration.

Firstly, N-phenylurea is used as a hydrogen peroxide stabilizer, 5-amino-tetrazole is used as an etching inhibitor, a mixture of isopropanolamine, malonic acid, sulfamic acid and phosphoric acid is used as an etching additive, and sodium hydroxide is used as a pH regulator, and different copper-molybdenum etchants are prepared according to a certain proportion, and are specifically shown in the following table 1:

TABLE 1

Ingredient (wt%)	Etching agent 1	Etchant 2	Etchant 3	Etching agent 4	Etching agent 5	Etching agent 6
							H2O2	18.7	18.7	18.7	18.7	18.7	18.7
H₂O₂Stabilizer	0.2	0	0.4	0.2	0.2	0.4
							Etching inhibitor	0.5	0.1	0.5	0.5	0.5	0.5
Etching additive	6.5	6.5	6.5	5.5	5	5
							pH regulator	2.5	2.5	2.5	1.5	1	1
Deionized water	71.6	72.2	71.4	73.6	74.6	74.4
							Etching assistant	9.7	9.1	9.9	7.7	6.7	6.9

The provided etchant is used for etching the copper molybdenum film layer (the laminated film layer formed by the 300 angstrom molybdenum film layer and the 7000 angstrom copper film layer, the molybdenum film layer is below the copper film layer) under different service lives of the etchant, and then the shape after etching is observed through a scanning electron microscope, and the CD loss, the Taper, whether molybdenum residue exists and whether the etching shape is good are sequentially evaluated, and the results are summarized as follows:

the test data after etching with etchant 1 are shown in table 2 below:

TABLE 2

The test data after etching with etchant 2 are shown in table 3 below:

TABLE 3

The test data after etching with etchant 3 are shown in table 4 below:

TABLE 4

The test data after etching with etchant 4 are given in table 5 below:

TABLE 5

The test data after etching using etchant 5 is shown in table 6 below:

TABLE 6

The test data after etching using etchant 6 are shown in table 7 below:

TABLE 7

From the above experimental data, it can be seen that, under the condition that the content of the etching auxiliary agent in the etchant is low, especially under the condition that the total amount of the etching auxiliary agent in the etchant 4 is only 7.7 wt%, a good etching effect can be obtained, on one hand, under the etching state that the CD loss is less than or equal to 0.7 micron, no molybdenum remains and a good etching morphology can be obtained, and meanwhile, the etching Taper can be controlled between 60 and 70 ℃ to meet the control specification of 65 ± 10 ℃, on the other hand, the etchant can maintain the stability of the etching performance when the lifetime reaches 7000ppm, thereby having a long service life.

The above-mentioned etchant life is the sum of the copper ion concentration and the molybdenum ion concentration in the etchant; CD loss refers to the distance that the edge of the patterned copper molybdenum metal layer formed after etching is retracted compared with the edge of the upper photoresist layer; taper refers to the angle of a Taper angle formed at the edge of the patterned copper-molybdenum metal layer formed after etching; the good etching morphology means that the patterned copper-molybdenum metal layer formed after etching does not have morphology defects such as molybdenum undercutting, film layer holes and the like.

In another embodiment of the present invention, a display panel is further provided, where the display panel includes a metal layer, the metal layer is made of a copper-molybdenum film and is formed by etching the copper-molybdenum film according to the etching method of the claim, where the metal layer may be a gate metal layer, a source/drain metal layer, or another metal layer that needs copper as a material to achieve low impedance, and this implementation does not limit this.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and parts that are not described in detail in a certain embodiment may refer to the above detailed descriptions of other embodiments, and are not described herein again.

The copper-molybdenum etchant composition, the etching method of the copper-molybdenum film layer and the display panel provided by the embodiment of the invention are described in detail, and the principle and the implementation mode of the invention are explained by applying specific examples, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for those skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A copper molybdenum etchant composition, comprising: the copper-molybdenum etching agent composition comprises hydrogen peroxide, water and an etching auxiliary agent, wherein the etching auxiliary agent accounts for 4 wt% -20 wt% of the copper-molybdenum etching agent composition by mass, and the etching auxiliary agent comprises a hydrogen peroxide stabilizer, an etching inhibitor, an etching additive and a pH regulator.

2. The copper-molybdenum etchant composition of claim 1, wherein the hydrogen peroxide is 10 wt% to 20 wt%, the hydrogen peroxide stabilizer is 0.1 wt% to 2 wt%, the etching inhibitor is 0.1 wt% to 1 wt%, the etching additive is 2 wt% to 10 wt%, and the pH adjuster is 0.1 wt% to 5 wt% in the copper-molybdenum etchant composition.

3. The copper molybdenum etchant composition of claim 1, wherein the hydrogen peroxide stabilizer is selected from at least one of urea compounds, phosphate salts, or alcohol compounds.

4. The copper molybdenum etchant composition of claim 1, wherein the etching inhibitor is at least one selected from the group consisting of azole compounds, thiophene compounds, indole compounds, purine compounds, pyrimidine compounds, and pyrrole compounds.

5. The copper molybdenum etchant composition of claim 1, wherein the etching additive is selected from at least two of an amine compound, an organic acid, and an inorganic acid.

6. The copper molybdenum etchant composition of claim 1, wherein the pH adjuster is at least one selected from the group consisting of an inorganic acid and an inorganic base.

7. The copper molybdenum etchant composition of claim 1, wherein the pH of the copper molybdenum etchant composition is from 2 to 4.

8. The etching method of the copper molybdenum film layer is characterized by comprising the following steps:

forming a light resistance layer on the copper molybdenum film layer;

etching the copper-molybdenum film layer by using the copper-molybdenum etchant composition of any one of claims 1 to 7 under the shielding of the photoresist layer; and

and stripping off the photoresist layer.

9. The method of claim 8, wherein the copper molybdenum etchant composition is at a temperature of 30-35 ℃.

10. A display panel, comprising a metal layer, wherein the metal layer is formed by etching the copper-molybdenum film according to any one of claims 8 and 9.