An etching solution for copper / molybdenum (niobium) / IGZO film layer and its preparation method and application

Abstract

The present invention provides an etching solution for copper / molybdenum (niobium) / IGZO film layer and its preparation method and application, the etching solution comprises a main agent and an additive, and the metal corrosion inhibitors in the main agent and the additive are aminocarbazole metal corrosion inhibitors. The etching solution of the present invention can realize the synchronous etching of the metal source and drain electrode and the semiconductor layer IGZO film layer, can reduce the number of masks used, simplify the IGZO-TFT manufacturing process, improve the production efficiency of the enterprise, reduce the production cost, ensure the product quality, and at the same time, the copper ion load of the etching solution can reach 8000ppm, and the service life is higher.

Description

Technical Field

[0001] The invention belongs to the field of metal surface chemical treatment, and relates to an etching solution for copper / molybdenum (niobium) / IGZO film layers, and a preparation method and application thereof. Background Art

[0002] Thin Film Transistor (TFT) is the core component of flat panel display, controlling the switch and color change of the display panel. TFT devices are composed of multiple layers of film stacked together. Each functional film layer needs to go through multiple masking processes. Each masking process includes steps such as coating, photoresist coating, exposure, development, etching, and photoresist stripping, which consumes a lot of costs. Therefore, the number of masking processes directly determines the production cost of the display panel.

[0003] In the traditional basic TFT manufacturing process, the film layers that need to use the mask process are the gate, active layer, source / drain electrode (S / D) layer, pixel perforated electrode layer, and pixel electrode layer. At present, si-TFT can achieve a production process with at least 4 masks. The active layer and S / D layer share a halftone mask (halftone mask, HTM) mask. The S / D film layer is wet etched with chemical liquid, and the Si film layer is dry etched. The specific steps are: after the resist layer on the S / D is exposed and developed by HTM, (i) the S / D metal layer outside the channel is removed with a metal etching solution, (ii) the unnecessary Si layer is removed by dry etching, (iii) the photoresist above the channel is removed by ashing, (iiii) the metal in the channel is removed with a metal etching solution, and (iiiii) the photoresist is stripped. However, the highest-level process of IGZO-TFT still requires 5 mask processes, and its production cost is still high, which puts companies under huge cost pressure.

[0004] The chemical properties of IGZO and S / D metal film layers are quite different, and different etching solutions are required for etching respectively. Currently, there is no etching solution that has good etching properties for both S / D and IGZO, so 4mask-IGZO-TFT has not been mass-produced. If the common characteristics of S / D metal etching solution and IGZO etching solution can be combined to develop an etching solution, the 4mask-IGZO-TFT process can be realized. The 4mask-IGZO-TFT process is as follows: after the resist layer on the S / D is exposed and developed by HTM, (i) the S / D metal layer and IGZO layer outside the channel are removed by etching solution, (ii) the photoresist above the channel is removed by ashing, (iii) the metal in the channel is removed by S / D metal etching solution, and (iiii) the photoresist is stripped.

[0005] Therefore, in order to shorten the production process of IGZO-TFT and increase corporate benefits, it is urgent to develop an etching solution that can etch the IGZO active layer and S / D source and drain electrodes at the same time. In addition, in order to better control the etching direction and etching rate and obtain better wiring shapes, existing hydrogen peroxide-based etching solutions often add azole corrosion inhibitors, such as 5-aminotetrazole and 3-aminotriazole, but the price of such azole corrosion inhibitors is quite high (the unit price per kilogram is as high as 800 to 900 yuan), which affects the profit level of enterprises.

[0006] Therefore, on the basis of ensuring the etching characteristics of the solution and the electrical characteristics of the product (or even better), reducing the production cost of the solution is also an issue that each solution manufacturer needs to consider. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide an etching solution for copper / molybdenum (niobium) / IGZO film layers and a preparation method and application thereof.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] On the one hand, the present invention provides an etching solution for copper / molybdenum (niobium) / IGZO film layer, the etching solution comprises a main agent and an additive, and the metal corrosion inhibitors in the main agent and the additive are aminocarbazole metal corrosion inhibitors.

[0010] In the present invention, aminocarbazole metal corrosion inhibitors are selected as the main agent and the metal corrosion inhibitor in the additive, which reduces the product cost on the one hand, and on the other hand, the addition of such corrosion inhibitors can obtain good etching morphology and has no effect on the electrical properties of the product.

[0011] In order to ensure the etching rate, preferably, the main agent and the additives also include fluorine-containing ion compounds.

[0012] Preferably, the main agent, with its total mass being 100%, comprises the following components:

[0013]

[0014] In the present invention, the formula composition of the main agent is screened. By using such a combination of components, the cost can be reduced on the one hand, and the service life and etching stability of the etching solution can be improved on the other hand.

[0015] In the main agent of the present invention, the mass percentage of the hydrogen peroxide can be 1%, 3%, 5%, 8%, 10%, 12%, 14%, 16%, 18% or 20%.

[0016] In the main agent of the present invention, the mass percentage of the nitric acid (calculated as its solute HNO3) can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0017] In the main agent of the present invention, the mass percentage of the fluorine-containing ionic compound can be 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%.

[0018] In the main agent of the present invention, the mass percentage of the amine compound or ammonium salt can be 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0019] In the main agent of the present invention, the mass percentage of the hydrogen peroxide stabilizer can be 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4% or 5%.

[0020] In the main agent of the present invention, the mass percentage of the metal corrosion inhibitor can be 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8% or 2%.

[0021] As a preferred technical solution, the main agent, with its total mass as 100%, includes the following components:

[0022]

[0023] Preferably, the additive, with its total mass being 100%, comprises the following components:

[0024]

[0025] In the additive of the present invention, the mass percentage of the nitric acid (calculated as its solute HNO3) can be 1%, 3%, 5%, 8%, 10%, 12%, 14%, 16%, 18% or 20%.

[0026] In the additive of the present invention, the mass percentage of the fluorine-containing ionic compound can be 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0027] In the additive of the present invention, the mass percentage of the amine compound or ammonium salt can be 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18% or 20%.

[0028] In the additive of the present invention, the mass percentage of the metal corrosion inhibitor can be 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 1.8% or 2%.

[0029] As a preferred technical solution, the additive, with its total mass as 100%, includes the following components:

[0030]

[0031] The copper / molybdenum (niobium) / IGZO film layer in the present invention refers to a metal copper layer / metal molybdenum layer / IGZO film layer, or a metal copper layer / molybdenum-niobium alloy layer / IGZO film layer.

[0032] It should be noted that, in the present invention, the mass percentage of the hydrogen peroxide is calculated based on the hydrogen peroxide in the hydrogen peroxide, and the mass percentage of the nitric acid is calculated based on the solute HNO3 in the nitric acid.

[0033] According to the technical solution provided by the present invention, through the chemical and electrochemical effects between different compounds with different mass percentages and the etching target, the target film layer can be simultaneously converted into a free ionic compound and etched, with excellent etching morphology and high etching accuracy, and finally showing a CD loss <1μm, a slope angle of 35°<60°, and at the same time will not cause damage to the electrical properties of each film layer.

[0034] Specifically, the strong oxidant hydrogen peroxide in the etching solution of the present invention undergoes oxidation reaction with metallic copper, metallic molybdenum (niobium) and unoxidized indium, gallium and zinc in IGZO, and changes the film structure. Subsequently, the nitric acid in the system undergoes an acidification reaction with substances such as copper oxide and zinc oxide, causing them to change from a solid state to a free state. The amine or ammonium salt in the system cooperates with the oxides of molybdenum and niobium to dissolve them in the solution. The fluoride in the system reacts with gallium oxide, indium oxide, etc. to generate metal fluoride ions. Therefore, the etching solution of the present invention can achieve synchronous etching of copper / molybdenum (niobium) / IGZO film layers.

[0035] In addition, in order for the above components to have a suitable etching rate ratio for each film layer, the etching rate of the copper metal film is the highest, so a metal corrosion inhibitor needs to be added to the system. In order to increase the storage period of the etching solution, a hydrogen peroxide stabilizer needs to be added to the system to reduce the decomposition rate of hydrogen peroxide.

[0036] In addition to forming complexes with metal oxides, the above-mentioned amine compounds or ammonium salts can also form complexes with copper ions to reduce the catalytic decomposition of free copper ions on hydrogen peroxide, which is extremely important for the high copper ion loading capacity of the etching solution. At the same time, they can also play a role in regulating the pH value, preventing large fluctuations in pH caused by nitric acid consumption, and playing a role in stabilizing the etching characteristics of the etching solution.

[0037] Preferably, the hydrogen peroxide of the present invention is electronic grade hydrogen peroxide, which can oxidize metal elements into metal oxides.

[0038] Preferably, the fluorine-containing ionic compound is selected from, but not limited to, any one of hydrofluoric acid (when hydrofluoric acid is selected, its mass percentage is calculated based on the solute HF in hydrofluoric acid), ammonium fluoride, ammonium bifluoride or tetramethylammonium fluoride, or a combination of at least two thereof.

[0039] Preferably, the fluorine-containing ionic compound is hydrofluoric acid. More preferably, the main agent comprises 0.01 to 3% by mass of hydrofluoric acid.

[0040] The amine compound and ammonium salt of the present invention play a role of pH buffering, can stabilize the pH value of the solution and stabilize the etching effect, and can also complex with copper ions to weaken the catalytic decomposition effect of copper ions on hydrogen peroxide and increase the life of the etching solution.

[0041] Preferably, the amine compound is a polyamine or an alcoholamine compound.

[0042] Furthermore, the amine compound includes any one of ethylenediamine, propylenediamine, dimethylethanolamine, diethylaminopropylamine, diethylethanolamine, triethanolamine or isopropanolamine, or a combination of at least two thereof.

[0043] Preferably, the ammonium salt includes any one of tetramethylammonium hydroxide, trimethylammonium hydroxide, ammonium acetate, ammonium chloride, ammonium sulfate or ammonium nitrate, or a combination of at least two thereof.

[0044] Of course, the amine compound and the ammonium salt in the etching solution can be used alone or in combination. The present invention does not particularly limit the ratio between the two compounds when used in combination.

[0045] The hydrogen peroxide stabilizer of the present invention can be used to inhibit the catalytic decomposition of hydrogen peroxide by trace metal ions during the storage of the etching solution, reduce the decomposition rate of hydrogen peroxide, and extend the storage and service life of the etching solution. Specifically, the hydrogen peroxide stabilizer of the present invention is selected from urea and / or sulfonic acid compounds. Preferably, the urea compound includes but is not limited to any one of phenylurea, thiourea or urea or a combination of at least two thereof; preferably, the sulfonic acid compound includes but is not limited to p-hydroxybenzenesulfonic acid and / or p-aminobenzenesulfonic acid.

[0046] The metal corrosion inhibitor of the present invention is an aminonitrogen azole compound. Since the etching rate of copper metal is greater than that of molybdenum-niobium alloy, if the metal slow release agent is not added, it will cause serious tailing of the molybdenum-niobium layer, resulting in poor electrical properties.

[0047] Specifically, in order to obtain better copper loading capacity and improve the service life of the etching solution, the metal corrosion inhibitor of the present invention is selected from aminocarbazole compounds, preferably 9-aminocarbazole and / or 3,9-diaminocarbazole. If the metal corrosion inhibitor in the etching solution is two or more of the aminocarbazole compounds, the present invention does not particularly limit the ratio between the compounds.

[0048] The second aspect of the present invention is to provide a method for preparing the etching solution for the copper / molybdenum (niobium) / IGZO film layer as described above, comprising the following steps:

[0049] (1) mixing hydrogen peroxide, nitric acid, fluorine-containing ionic compounds, amine compounds and / or ammonium salts, hydrogen peroxide stabilizers, and metal corrosion inhibitors in water to obtain a main agent for an etching solution for a copper / molybdenum (niobium) / IGZO film layer;

[0050] (2) Nitric acid, fluorine-containing ionic compounds, amine compounds or ammonium salts, and metal corrosion inhibitors are mixed and stirred in water to obtain an etching solution additive for copper / molybdenum (niobium) / IGZO film layers, that is, the etching solution for copper / molybdenum (niobium) / IGZO film layers is obtained.

[0051] In the preparation method, the mass percentage of each component in the etching solution is the same as described above and will not be repeated here.

[0052] Specifically, in order to produce the etching solution main agent, nitric acid is first mixed with water and stirred, and the temperature is maintained below 45°C (for example, 45°C, 40°C, 38°C, 35°C, 30°C, 28°C, 25°C, 20°C, etc.). Then, fluorine-containing ion compounds, amine compounds and / or ammonium salts, hydrogen peroxide stabilizers, metal corrosion inhibitors and hydrogen peroxide are sequentially added to the mixed system, and it can be used after filtering through 0.5μm and 0.2μm filter elements. The temperature of the liquid system is maintained below 45°C to prevent the components of the liquid from decomposing or reacting with each other at higher temperatures.

[0053] Specifically, in order to produce etching solution additives, nitric acid is first mixed with water and stirred, and the temperature is maintained below 45°C (for example, 45°C, 40°C, 38°C, 35°C, 30°C, 28°C, 25°C, 20°C, etc.). Then, fluorine-containing ionic compounds, amine compounds and / or ammonium salts, and metal corrosion inhibitors are sequentially added to the mixed system, and the mixture can be used after filtering with 0.5μm and 0.2μm filter elements. The temperature of the liquid system is maintained below 45°C to prevent the components of the liquid from decomposing or reacting with each other at higher temperatures.

[0054] The preparation method of the etching solution of the present invention is simple, and can realize safe and large-scale production of the etching solution which can simultaneously etch the metal layer and the IGZO film layer and has excellent etching accuracy.

[0055] The third aspect of the present invention is to provide a method for etching a copper / molybdenum (niobium) / IGZO film layer, wherein the etching method uses the etching solution as described above for etching, and as the number of etching substrates increases, the copper ion concentration in the etching solution will continue to increase, and for every 100 ppm increase in the copper ion concentration, 0.05-0.15% by mass of an additive needs to be added to the system. The etching method can achieve synchronous etching of the metal layer and the IGZO film layer, and the etching characteristics are stable and uniform.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] 1. The etching solution for copper / molybdenum (niobium) / IGZO film layer of the present invention realizes the synchronous etching of the metal source and drain and the semiconductor layer IGZO film layer through electrochemical and chemical corrosion of different components and different film layers.

[0058] 2. The etching solution for copper / molybdenum (niobium) / IGZO film layer of the present invention stabilizes the etching rate ratio of copper / molybdenum (niobium) / IGZO film layer by adjusting the ratio of different components, and obtains electrical properties and etching morphology that meet product quality requirements, such as CD loss of less than 1μm on one side and a slope angle of 30-60 degrees.

[0059] 3. The etching solution for copper / molybdenum (niobium) / IGZO film layer of the present invention adopts a combination of a main agent and an auxiliary agent (i.e., an additive) to increase the copper ion loading capacity to 8000 ppm, and has the characteristic of a longer service life.

[0060] 4. The etching solution for copper / molybdenum (niobium) / IGZO film layer of the present invention has cheap and easily available raw materials, which can help enterprises reduce costs and increase efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1A The SEM images of the cross section and the etched surface of the etching solution of Example 1 of the present invention when the copper ion concentration is 0 ppm and the etching is performed for 125 seconds, and the scale is 1 μm;

[0062] Figure 1B This is a SEM image of the etched surface of the etching solution of Example 1 of the present invention when the copper ion concentration is 0 ppm and the etching time is 125 seconds, and the scale is 1 μm;

[0063] Figure 2A This is a SEM image of the cross section of the etching solution of Example 2 of the present invention when the copper ion concentration is 0 ppm and the etching time is 120 s, and the scale is 1 μm;

[0064] Figure 2B This is a SEM image of the etched surface of the etching solution of Example 2 of the present invention when the copper ion concentration is 0 ppm and the etching time is 120 seconds, and the scale is 1 μm;

[0065] Figure 3A This is a SEM image of the cross section of the etching solution of Comparative Example 1 of the present invention when the copper ion concentration is 0 ppm and the etching time is 300 s, and the scale is 1 μm;

[0066] Figure 3B This is a SEM image of the etching surface of the etching solution of Comparative Example 1 of the present invention when the copper ion concentration is 0 ppm and the etching time is 300 seconds, and the scale is 1 μm;

[0067] Figure 4A This is a SEM image of the cross section of the etching solution of Example 1 of the present invention when the copper ion concentration is 2000ppm and the etching is 125s, and the scale is 1μm;

[0068] Figure 4B This is a SEM image of the etched surface of the etching solution of Example 1 of the present invention when the copper ion concentration is 2000ppm and the etching time is 125s, and the scale is 1μm;

[0069] Figure 5A This is a SEM image of the cross section of the etching solution of Example 1 of the present invention when the copper ion concentration is 4000ppm and the etching is 125s, and the scale is 1μm;

[0070] Figure 5B This is a SEM image of the etched surface of the etching solution of Example 1 of the present invention when the copper ion concentration is 4000ppm and the etching time is 125s, and the scale is 1μm;

[0071] Fig. 6A This is a SEM image of the cross section of the etching solution of Example 1 of the present invention when the copper ion concentration is 6000ppm and the etching is 125s, and the scale is 1μm;

[0072] Figure 6B This is a SEM image of the etched surface of the etching solution of Example 1 of the present invention when the copper ion concentration is 6000ppm and the etching time is 125s, and the scale is 10μm;

[0073] Fig. 7AThis is a SEM image of the cross section of the etching solution of Example 1 of the present invention when the copper ion concentration is 8000ppm and the etching is 125s, and the scale is 1μm;

[0074] Figure 7B This is a SEM image of the etched surface of the etching solution of Example 1 of the present invention when the copper ion concentration is 8000ppm and the etching time is 125s, and the scale is 1μm;

[0075] Fig. 8A This is a SEM image of the cross section of the etching solution of Example 2 of the present invention when the copper ion concentration is 2000ppm and the etching is performed for 120s, and the scale is 1μm;

[0076] Figure 8B This is a SEM image of the etched surface of the etching solution of Example 2 of the present invention when the copper ion concentration is 2000ppm and the etching is performed for 120s, and the scale is 1μm;

[0077] Fig. 9A This is a SEM image of the cross section of the etching solution of Example 2 of the present invention when the copper ion concentration is 4000ppm and the etching is performed for 120s, and the scale is 1μm;

[0078] Fig. 9B This is a SEM image of the etched surface of the etching solution of Example 2 of the present invention when the copper ion concentration is 4000ppm and the etching is performed for 120s, and the scale is 1μm;

[0079] Fig. 10A This is a SEM image of the cross section of the etching solution of Example 2 of the present invention when the copper ion concentration is 6000ppm and the etching is performed for 120s, and the scale is 1μm;

[0080] Fig. 10B This is a SEM image of the etched surface of the etching solution of Example 2 of the present invention when the copper ion concentration is 6000ppm and the etching is performed for 120s, and the scale is 1μm;

[0081] Fig.11A This is a SEM image of the cross section of the etching solution of Example 2 of the present invention when the copper ion concentration is 8000ppm and the etching is performed for 120s, and the scale is 1μm;

[0082] Fig. 11B This is a SEM image of the etched surface of the etching solution of Example 2 of the present invention when the copper ion concentration is 8000 ppm and the etching is performed for 120 seconds, and the scale is 1 μm. DETAILED DESCRIPTION

[0083] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0084] Example 1

[0085] The etching solution A (i.e., main agent, the same below) for the copper / molybdenum (niobium) / IGZO film layer of this embodiment includes the following components according to the mass percentage:

[0086]

[0087] Mix the above nitric acid and water and stir, then add hydrofluoric acid, tetramethylammonium hydroxide, phenylurea, 9-aminocarbazole and hydrogen peroxide to the mixed system in sequence and stir. Filter through 0.5μm and 0.2μm filter cartridges in sequence before use. The pH value of the A agent is 3.1.

[0088] The temperature of the etching solution A system is maintained below 45° C. during the entire preparation process.

[0089] The etching solution B agent (i.e., additive, the same below) for the copper / molybdenum (niobium) / IGZO film layer of this embodiment includes the following components according to the percentage by mass:

[0090]

[0091] Mix the above nitric acid and water and stir, then add hydrofluoric acid, tetramethylammonium hydroxide and 9-aminocarbazole to the mixed system and stir. Filter through 0.5μm and 0.2μm filter cartridges in turn before use. The pH value of the B agent is 2.

[0092] The temperature of the etching solution B system is maintained below 45° C. during the entire preparation process.

[0093] Example 2

[0094] The etching solution A for the copper / molybdenum (niobium) / IGZO film layer of this embodiment includes the following components in terms of mass percentage:

[0095]

[0096] Mix the above nitric acid with water and stir, then add ammonium fluoride, tetramethylammonium hydroxide, phenylurea, 3,9-diaminocarbazole and hydrogen peroxide to the mixed system in sequence and stir. Filter through 0.5μm and 0.2μm filter cartridges in sequence before use. The pH value of the A agent is 3.1.

[0097] The temperature of the etching solution A system is maintained below 45° C. during the entire preparation process.

[0098] The etching solution B for the copper / molybdenum (niobium) / IGZO film layer of this embodiment includes the following components according to mass percentage:

[0099]

[0100] Mix the above nitric acid with water and stir, then add ammonium fluoride, tetramethylammonium hydroxide and 3,9-diaminocarbazole to the mixed system and stir. Filter through 0.5μm and 0.2μm filter cartridges in turn before use. The pH value of the B agent is 2.05.

[0101] The temperature of the etching solution B system is maintained below 45° C. during the entire preparation process.

[0102] Example 3

[0103] The etching solution A for the copper / molybdenum (niobium) / IGZO film layer of this embodiment includes the following components in terms of mass percentage:

[0104]

[0105] Mix the above nitric acid with water and stir, then add hydrofluoric acid, tetramethylammonium hydroxide, phenylurea, 3,9-diaminocarbazole and hydrogen peroxide to the mixed system in sequence and stir. Filter through 0.5μm and 0.2μm filter cartridges in sequence before use. The pH value of the A agent is 3.1.

[0106] The temperature of the etching solution A system is maintained below 45° C. during the entire preparation process.

[0107] The etching solution B for the copper / molybdenum (niobium) / IGZO film layer of this embodiment includes the following components according to mass percentage:

[0108]

[0109] Mix the above nitric acid and water and stir, then add hydrofluoric acid, tetramethylammonium hydroxide and 3,9-diaminocarbazole to the mixed system and stir. Filter through 0.5μm and 0.2μm filter cartridges in turn before use. The pH value of the B agent is 2.2.

[0110] The temperature of the etching solution B system is maintained below 45° C. during the entire preparation process.

[0111] Example 4

[0112] The etching solution A for the copper / molybdenum (niobium) / IGZO film layer of this embodiment includes the following components in terms of mass percentage:

[0113]

[0114]

[0115] Mix the above nitric acid with water and stir, then add hydrofluoric acid, tetramethylammonium hydroxide, phenylurea, 3,9-diaminocarbazole and hydrogen peroxide to the mixed system in sequence and stir. Filter through 0.5μm and 0.2μm filter cartridges in sequence before use. The pH value of the A agent is 3.

[0116] The temperature of the etching solution A system is maintained below 45° C. during the entire preparation process.

[0117] The etching solution B for the copper / molybdenum (niobium) / IGZO film layer of this embodiment includes the following components according to mass percentage:

[0118]

[0119] Mix the above nitric acid and water and stir, then add hydrofluoric acid, tetramethylammonium hydroxide and 3,9-diaminocarbazole to the mixed system and stir. Filter through 0.5μm and 0.2μm filter cartridges in turn before use. The pH value of the B agent is 2.

[0120] The temperature of the etching solution B system is maintained below 45° C. during the entire preparation process.

[0121] Comparative Example 1

[0122] The etching solution A for the copper / molybdenum (niobium) / IGZO film layer of this comparative example includes the following components according to the mass percentage:

[0123]

[0124]

[0125] Mix the above nitric acid with water and stir, then add tetramethylammonium hydroxide, phenylurea, 9-aminocarbazole and hydrogen peroxide to the mixed system in sequence and stir. Filter through 0.5μm and 0.2μm filter cartridges in sequence before use. The pH value of the A agent is 3.05.

[0126] The temperature of the etching solution A system is maintained below 45° C. during the entire preparation process.

[0127] The etching solution B for the copper / molybdenum (niobium) / IGZO film layer of this comparative example includes the following components according to the mass percentage:

[0128]

[0129] Mix the above nitric acid with water and stir, then add tetramethylammonium hydroxide and 9-aminocarbazole to the mixed system and stir. Filter through 0.5μm and 0.2μm filter cartridges in turn before use. The pH value of the B agent is 1.98.

[0130] The temperature of the etching solution B system is maintained below 45° C. during the entire preparation process.

[0131] Comparative Example 2

[0132] The etching solution A for the copper / molybdenum (niobium) / IGZO film layer of this comparative example includes the following components according to the mass percentage:

[0133]

[0134]

[0135] Mix the above nitric acid and water and stir, then add hydrofluoric acid, tetramethylammonium hydroxide, phenylurea, 9-aminocarbazole and hydrogen peroxide to the mixed system in sequence and stir. Filter through 0.5μm and 0.2μm filter cartridges in sequence before use. The pH value of the A agent is 2.9.

[0136] The temperature of the etching solution A system is maintained below 45° C. during the entire preparation process.

[0137] The etching solution B for the copper / molybdenum (niobium) / IGZO film layer of this comparative example includes the following components according to the mass percentage:

[0138]

[0139] Mix the above nitric acid and water and stir, then add hydrofluoric acid, tetramethylammonium hydroxide and 9-aminocarbazole to the mixed system and stir. Filter through 0.5μm and 0.2μm filter cartridges in turn before use. The pH value of the B agent is 2.05.

[0140] The temperature of the etching solution B system is maintained below 45° C. during the entire preparation process.

[0141] Comparative Example 3

[0142] The etching solution A for the copper / molybdenum (niobium) / IGZO film layer of this comparative example includes the following components according to the mass percentage:

[0143]

[0144]

[0145] Mix the above nitric acid with water and stir, then add ammonium fluoride, tetramethylammonium hydroxide, phenylurea, 3-aminotetrazole and hydrogen peroxide to the mixed system in sequence and stir. Filter through 0.5μm and 0.2μm filter cartridges in sequence before use. The pH value of the A agent is 2.98.

[0146] The temperature of the etching solution A system is maintained below 45° C. during the entire preparation process.

[0147] The etching solution B for the copper / molybdenum (niobium) / IGZO film layer of this comparative example includes the following components according to the mass percentage:

[0148]

[0149] Mix the above nitric acid with water and stir, then add ammonium fluoride, tetramethylammonium hydroxide and 3-aminotetrazole to the mixed system and stir. Filter through 0.5μm and 0.2μm filter cartridges in turn before use. The pH value of the B agent is 2.05.

[0150] The temperature of the etching solution B system is maintained below 45° C. during the entire preparation process.

[0151] Etching condition capture

[0152] A hand-cranked small etching machine was used to etch the metal copper layer / molybdenum alloy layer / IGZO film layer (4500A / 200A / 600A) on the surface of the glass substrate using the etching solutions of the above Examples 1-4 and Comparative Examples 1-3. For every 100 ppm increase in the copper ion concentration, 0.1% mass fraction of agent B was added to the system. The etching conditions and etching results are shown in Table 1.

[0153] From the perspective of production safety, the etching solution system containing hydrogen peroxide should adopt a relatively mild etching temperature, and the etching temperature is preferably below 35°C. Through condition grabbing experiments, it was determined that the etching temperatures corresponding to Examples 1-4 were 32°C, 34°C, 31°C and 32°C, respectively, and the optimal etching times were 125s, 120s, 122s and 135s, respectively. The SEM photos of the etching results corresponding to Examples 1 and 2 are shown in Figure 1A , Figure 1B and Figure 2A , Figure 2B (Measured using Hitachi's S-3400N scanning electron microscope). Comparative Example 1 does not have sufficient etching capability for the metal copper layer / molybdenum alloy layer / IGZO film layer even under the etching conditions of 34°C and 300s. The corresponding SEM photos of the etching results are shown in Figure 3A and Figure 3B .

[0154] Table 1

[0155]

[0156] According to Table 1, the etching solutions in Examples 1-4 can not only realize the synchronous etching of the metal layer and the IGZO film layer, but also have high etching accuracy, and can present CD loss (single-sided line width loss) and slope angle that meet the customer's process requirements, have good etching morphology, no chamfers are generated, and have excellent electrical properties. However, since no fluorine-containing ion reagent is added to the etching solution of Comparative Example 1, there is still no obvious corrosion of IGZO after etching for 300 seconds; the content of fluorine-containing ion reagent in Comparative Example 2 is high, the corrosion rate is too fast, and problems such as chamfering and poor electrical properties are prone to occur; from the comparison of Examples 1-4 and Comparative Example 3, it can be seen that aminocarbazole metal corrosion inhibitors are used in the etching solution of the present invention, and the etching rate and morphology level achieved are equivalent to the effects of the etching solution using aminonitrogen azole metal corrosion inhibitors commonly used in the prior art, but the unit price of aminocarbazole chemicals (less than 100 yuan per kilogram) is one order of magnitude lower than that of 5-aminotetrazole and 3-aminotriazole. Therefore, aminocarbazole corrosion inhibitors have obvious cost advantages over corrosion inhibitors such as 5-aminotetrazole and 3-aminotriazole.

[0157] Copper load capacity verification

[0158] Step 1: The etching solution A of Example 1 was heated to 32° C. After cyclic spraying and temperature stabilization, the sample was etched for 125 seconds, cleaned and dried to obtain sample 1*. The etching results were observed by SEM, and the etching results are shown in FIG1 .

[0159] Step 2: Add 2% mass fraction of agent B to the etching tank, and add copper powder to make the copper ion concentration in the etching solution 2000ppm. Raise the temperature to 32℃, after circulating spraying and temperature stabilization, take the sample and etch for 125s, clean and dry to obtain sample 2*. Observe the etching results with SEM, the etching results are shown in Figure 4A and Figure 4B .

[0160] Step 3: Add 2% mass fraction of agent B to the etching tank, and add copper powder to make the copper ion concentration in the etching solution 4000ppm. Raise the temperature to 32℃, after circulating spraying and temperature stabilization, take the sample and etch for 125s, clean and dry to obtain sample 3*. Observe the etching results with SEM, the etching results are shown in Figure 5A and Figure 5B .

[0161] Step 4: Add 2% mass fraction of agent B to the etching tank, and add copper powder to make the copper ion concentration in the etching solution 6000ppm. Raise the temperature to 32℃, after circulating spraying and temperature stabilization, take the sample and etch for 125s, clean and dry to obtain sample 4*. Observe the etching results with SEM, the etching results are shown in Fig. 6A and Figure 6B .

[0162] Step 5: Add 2% mass fraction of agent B to the etching tank, and add copper powder to make the copper ion concentration in the etching solution 8000ppm. Raise the temperature to 32℃, after circulating spraying and temperature stabilization, take the sample and etch for 125s, clean and dry to obtain sample 5*. Observe the etching results with SEM, the etching results are shown in Fig. 7A and Figure 7B .

[0163] The following Table 2 shows the etching characteristics of the etching solution of Example 1:

[0164] Table 2

[0165] Copper ion concentration (ppm) 0 2000 4000 6000 8000 Taper(°) 39 40 39 41 43 CD-loss(μm) 0.73 0.76 0.79 0.82 0.80 Residue none none none none none

[0166] Similarly, the etching solution of Example 2 is subjected to the same operation under the corresponding etching conditions according to the above method. Figures 8A to 11B The SEM cross-sectional photographs of the etching results when the copper concentration of the etching solution of Example 2 is 0-8000 ppm, wherein the copper concentration in FIG2 is 0 ppm, Fig. 8A and Figure 8B The copper concentration is 2000ppm, Fig. 9A and Fig. 9B The copper concentration is 4000ppm, Fig. 10A and Fig. 10B The copper concentration is 6000ppm, Fig.11A and Fig. 11B The copper concentration is 8000ppm. Table 3 below shows the etching characteristics of the etching solution of Example 2:

[0167] Table 3

[0168] Copper ion concentration (ppm) 0 2000 4000 6000 8000 Taper(°) 43 42 45 45 46 CD-loss(μm) 0.79 0.82 0.86 0.85 0.81 Residue none none none none none

[0169] Similarly, the etching solution of Example 3 is subjected to the same operation under the corresponding etching conditions according to the above method. The etching characteristics of the etching solution of Example 3 are shown in Table 4 below:

[0170] Table 4

[0171] Copper ion concentration (ppm) 0 2000 4000 6000 8000 Taper(°) 49 52 52 54 53 CD-loss(μm) 0.74 0.78 0.84 0.89 0.88 Residue none none none none none

[0172] Similarly, the etching solution of Comparative Example 3 is subjected to the same operation under the corresponding etching conditions according to the above method. The etching characteristics of the etching solution of Comparative Example 3 are shown in Table 5 below:

[0173] Table 5

[0174] Copper ion concentration (ppm) 0 2000 4000 6000 8000 Taper(°) 50 52 51 54 53 CD-loss(μm) 0.95 0.99 1.18 1.22 1.14 Residue none none none none none

[0175] From the comparison of Table 2-Table 5, it can be seen that the etching solutions of Examples 1-3 of the present invention can achieve synchronous etching of the metal layer and the IGZO film layer, and the etching effect is still stable and excellent under high copper load. However, the etching results of the etching solution of Comparative Example 3 show the shortcomings of the etching characteristics of the liquid. Under high copper load, CD-loss is difficult to control and cannot meet the production requirements of high precision and high resolution. Therefore, the etching solution containing aminocarbazole metal corrosion inhibitor of the present invention also has a higher copper loading capacity and a longer service life.

[0176] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the etching solution for copper / molybdenum (niobium) / IGZO film layer and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An etching solution for copper / molybdenum / IGZO film or copper / molybdenum-niobium alloy / IGZO film, characterized in that: The etching solution includes a main agent and an additive; The main agent, with its total mass as 100%, includes the following components: The additive, with its total mass being 100%, comprises the following components: The metal corrosion inhibitors in the main agent and the additive are 9-aminocarbazole and / or 3,9-diaminocarbazole.

2. The etching solution according to claim 1, characterized in that: The main agent, with its total mass as 100%, includes the following components:

3. The etching solution according to claim 1, characterized in that: The additive, with its total mass being 100%, comprises the following components:

4. The etching solution according to claim 1, characterized in that: The hydrogen peroxide is electronic grade hydrogen peroxide.

5. The etching solution according to claim 1, characterized in that: The fluorine-containing ionic compound is selected from any one of hydrofluoric acid, ammonium fluoride, ammonium bifluoride or tetramethylammonium fluoride, or a combination of at least two thereof.

6. The etching solution according to claim 5, characterized in that: The fluorine-containing ionic compound is hydrofluoric acid.

7. The etching solution according to claim 6, characterized in that: The main agent includes 0.01-3% by mass of hydrofluoric acid.

8. The etching solution according to claim 1, characterized in that: The amine compound is a polyamine or an alcohol amine compound.

9. The etching solution according to claim 8, characterized in that: The amine compound includes any one of ethylenediamine, propylenediamine, dimethylethanolamine, diethylaminopropylamine, diethylethanolamine, triethanolamine or isopropanolamine, or a combination of at least two thereof.

10. The etching solution according to claim 1, characterized in that: The ammonium salt includes any one of tetramethylammonium hydroxide, trimethylammonium hydroxide, ammonium acetate, ammonium chloride, ammonium sulfate or ammonium nitrate, or a combination of at least two thereof.

11. The etching solution according to claim 1, characterized in that: The hydrogen peroxide stabilizer is selected from urea and / or sulfonic acid compounds.

12. The etching solution according to claim 11, characterized in that: The urea compound includes any one of phenylurea, thiourea or urea, or a combination of at least two of them.

13. The etching solution according to claim 12, characterized in that: The sulfonic acid compounds include p-hydroxybenzenesulfonic acid and / or p-aminobenzenesulfonic acid.

14. The method for preparing an etching solution according to any one of claims 1 to 13, characterized in that: The method comprises the following steps: (1) mixing hydrogen peroxide, nitric acid, fluorine-containing ion compounds, amine compounds and / or ammonium salts, hydrogen peroxide stabilizers, and metal corrosion inhibitors in water to obtain an etching solution main agent; (2) Nitric acid, fluorine-containing ion compounds, amine compounds or ammonium salts, and metal corrosion inhibitors are mixed and stirred in water to obtain an etching solution additive, that is, the etching solution for the copper / molybdenum (niobium) / IGZO film layer is obtained.

15. The preparation method according to claim 14, characterized in that: The mixing temperature in step (1) and step (2) is maintained below 45°C.

16. A method for etching a copper / molybdenum / IGZO film layer or a copper / molybdenum-niobium alloy / IGZO film layer, characterized in that: The etching method uses the etching solution as described in any one of claims 1 to 13 to perform etching.

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