Titanium etching solution, method of making and use in surface treatment of semiconductor ceramic plates

Abstract

The application relates to a titanium etching solution, a preparation method thereof and application of the titanium etching solution to surface treatment of a semiconductor ceramic plate. The titanium etching solution comprises raw materials with the following weight components: 1.8-3.0% of inorganic alkali; 4.0-10.0% of hydrogen peroxide; 0.5-1.0% of a stabilizer; 0.05-0.3% of a copper surface protective agent; 0.2-0.6% of an accelerator; and the balance of deionized water. The preparation method of the titanium etching solution specifically comprises the following steps: providing the raw materials of the above components, adding the deionized water, the inorganic alkali, the hydrogen peroxide, the stabilizer, the copper surface protective agent and the accelerator into an etching tank in sequence and stirring for 5-10 min. When the titanium etching solution is applied to surface treatment of the semiconductor ceramic plate, the temperature of etching treatment is constant titanium removal at 50-60 DEG C, and the time of etching treatment is 30-100 s. The application provides the titanium etching solution with good etching uniformity, high etching rate and high etching factor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor ceramic plate surface treatment, in particular to a titanium etching solution, a preparation method thereof and application thereof in semiconductor ceramic plate surface treatment. BACKGROUND

[0002] Semiconductor ceramic parts can achieve conductive performance through electroplating, in which the titanium layer plays a key role. Specifically, by sputtering a thin film of metallic titanium as an adhesion layer, the bonding strength between the metal and the ceramic substrate can be improved. This increase in bonding strength helps to optimize the overall performance and stability of the semiconductor ceramic plate. At the same time, it also reduces the thermal stress of the ceramic substrate during operation.

[0003] However, during the later forming process of the ceramic plate, part of the copper and titanium metal must be etched away to form the circuit. Currently, the semiconductor ceramic plate etching production line mainly uses horizontal lines and spray modes for etching. Such equipment usually includes a tank containing etching solution and one or more nozzles for spraying etching solution onto the ceramic plate. During operation, the ceramic plate is placed horizontally on a conveyor belt, and by moving the conveyor belt, the ceramic plate passes through the spray area. The etching time of titanium is usually between 60-120 seconds.

[0004] A Chinese patent (application publication number CN117904632A) discloses a semiconductor titanium etching solution, the composition of which is as follows:

[0005] Hydrogen peroxide: 8-25 parts;

[0006] Organic polyphosphonic acid and its derivatives: 1-20 parts;

[0007] Ammonium polycarboxylate: 1-7 parts;

[0008] Phosphoric acid ester ether compound: 0.5-2 parts;

[0009] Ultra-pure water: 40-65 parts.

[0010] However, the highest etching rate of this etching solution in immersion mode is only 900 Å / min, which can only be applied to semiconductor chip manufacturing processes and cannot meet the needs of semiconductor ceramic substrate production processes. In ceramic substrate horizontal line production, this etching solution is difficult to meet production standards, seriously affecting production efficiency.

[0011] Therefore, an important problem faced by the semiconductor ceramic substrate production field is how to improve production efficiency while ensuring etching quality. This requires the development of more efficient etching solutions and the optimization of production processes. SUMMARY

[0012] The prior art is in urgent need of a titanium etching solution which can improve production efficiency while ensuring etching quality, and therefore the application provides a titanium etching solution, a preparation method thereof and application in surface treatment of semiconductor ceramic plates to solve the above problems.

[0013] To achieve the above-mentioned purpose, in a first aspect, the application provides a titanium etching solution comprising the following raw materials by weight:

[0014] 1.8-3.0% of inorganic alkali;

[0015] 4.0-10.0% of hydrogen peroxide;

[0016] 0.5-1.0% of stabilizer;

[0017] 0.05-0.3% of copper surface protective agent;

[0018] 0.2-0.6% of accelerator;

[0019] and the balance of deionized water.

[0020] In an implementation manner, the inorganic alkali comprises one or a combination of sodium hydroxide, potassium hydroxide and calcium hydroxide.

[0021] In an implementation manner, the stabilizer comprises one or a combination of ethylenediamine, cyclohexylamine, n-octylamine, monoethanolamine, triethanolamine, disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, olefin and derivatives thereof.

[0022] In an implementation manner, the copper surface protective agent comprises one or a combination of 4-amino tetrazole, benzotriazole, methyl imidazole, mercapto-alkyl benzimidazole and imidazole.

[0023] In an implementation manner, the accelerator comprises one or a combination of tripropylene glycol methyl ether, diethylene glycol butyl ether, diethylene glycol methyl ether, methyl ether, ethyl ether, 1,6-fructose disodium phosphate and methyl ether eugenol.

[0024] In an implementation manner, the titanium etching solution comprises the following raw materials by weight:

[0025] 3.0% of potassium hydroxide;

[0026] 9.0% of hydrogen peroxide; wherein the concentration of the hydrogen peroxide is 30%;

[0027] 0.8% of stabilizer; wherein the stabilizer is olefin and derivatives thereof and disodium ethylenediaminetetraacetate in a weight ratio of 1:1.5;

[0028] 0.3% of copper surface protective agent; wherein the copper surface protective agent is methyl imidazole and imidazole in a weight ratio of 1:0.8;

[0029] 0.6% of accelerator; wherein the accelerator is diethylene glycol butyl ether and methyl ether eugenol in a weight ratio of 1:0.2;

[0030] and a balance of deionized water.

[0031] In a second aspect, the present application further provides a preparation method of the titanium etching liquid, which specifically comprises the following steps: providing the raw material components of the titanium etching liquid according to any one of the above embodiments, and adding the deionized water, the inorganic base, the hydrogen peroxide, the stabilizer, the copper surface protective agent and the accelerator into an etching tank in sequence, and stirring for 5-10 minutes when adding the raw materials.

[0032] In a third aspect, the present application further provides an application of the titanium etching liquid in the surface treatment of a semiconductor ceramic plate, which uses the titanium etching liquid according to any one of the above embodiments to perform etching treatment on the titanium layer on the surface of the semiconductor ceramic plate.

[0033] In an implementation manner, the temperature of the etching treatment is constant temperature titanium removal at 50-60°C, and the time of the etching treatment is 30-100s.

[0034] Beneficial effects: The present application provides a titanium etching liquid, a preparation method thereof and an application thereof in the surface treatment of a semiconductor ceramic plate. The inorganic base-hydrogen peroxide system titanium etching liquid is prepared, which can effectively and quickly remove the titanium layer on the surface of the semiconductor ceramic plate, does not corrode the silicon nitride, aluminum nitride, silicon oxide and aluminum oxide ceramic substrate, does not erode the copper layer, has good etching uniformity, fast etching rate, high etching factor, and can be applied to the etching treatment of the titanium surface treatment process of the semiconductor ceramic plate. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below with examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application. In addition, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" described below means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the technical features involved in each embodiment of the present application can be combined with each other as long as they do not conflict with each other.

[0036] The present application provides a titanium etching liquid, which comprises the following raw materials by weight:

[0037] 1.8-3.0% of inorganic base;

[0038] 4.0-10.0% of hydrogen peroxide;

[0039] 0.5-1.0% of stabilizer;

[0040] 0.05-0.3% of copper surface protective agent;

[0041] 0.2-0.6% of accelerator;

[0042] and the balance of deionized water.

[0043] The inorganic base can adjust the environment of the liquid to be alkaline, and the addition of hydrogen peroxide is the main oxidizing agent for the titanium layer, which plays a main etching role on the titanium metal, and the alkaline liquid environment can enhance the etching of the titanium metal. The addition of stabilizer can maintain the stability of the etching liquid and prevent the decomposition or failure of hydrogen peroxide during use. The copper surface protective agent is used to inhibit the corrosion of the liquid to the copper metal, and to protect the copper metal from etching titanium metal. The accelerator is used to adjust the etching speed and etching depth of the etching liquid to achieve uniform etching.

[0044] Specifically, the inorganic base includes one or a combination of sodium hydroxide, potassium hydroxide and calcium hydroxide. The concentration of hydrogen peroxide is 30%. The titanium etching liquid provided by the present application is activated under alkaline conditions, and the presence of heavy metal ions can cause hydrogen peroxide to be catalytically decomposed prematurely. The stabilizer can react with active oxygen ions (O 2- ) in hydrogen peroxide, thereby reducing the concentration of active oxygen ions and delaying the decomposition rate of hydrogen peroxide.

[0045] Specifically, the stabilizer includes one or a combination of ethylenediamine, cyclohexylamine, n-octylamine, monoethanolamine, triethanolamine, disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, olefins and derivatives thereof.

[0046] Specifically, the copper surface protective agent includes one or a combination of 4-amino tetrazole, benzotriazole, methyl imidazole, mercapto 2-sulfur benzimidazole and imidazole. The addition of azole and imidazole in the copper surface protective agent can form an adsorption layer on the copper surface to achieve the effect of protecting the copper surface, thereby reducing the oxidation and etching of the copper surface.

[0047] Specifically, the accelerator comprises one or a combination of the following: tripropylene glycol methyl ether, diethylene glycol butyl ether, diethylene glycol methyl ether, methyl ether, ethyl ether, 1,6-fructose disodium phosphate, and methyl ether eugenol. The accelerator also has an amplification effect: cleaning the dirt and stains on the surface of the plate, increasing the surface tension, improving the cleanliness of the plate, enhancing the contact effect of the titanium etching solution on the surface of the plate, and improving the performance of the titanium etching solution.

[0048] Further, the stabilizer and the copper surface protective agent can form a complex with these metal ions to prevent their catalytic decomposition of hydrogen peroxide. The imidazole compound in the copper surface protective agent can add to the olefins and their derivatives in the stabilizer to generate a 3-onium salt zwitterion, which then undergoes nucleophilic addition with another molecule of the dieneophile to generate a C-2 cyclized product, preventing the decomposition of hydrogen peroxide at high temperatures. The addition of the accelerator can increase the oxidation effect of hydrogen peroxide on titanium metal, achieving the effect of rapid titanium etching.

[0049] The application also provides a preparation method of the titanium etching solution, which specifically comprises the following steps: providing the raw material components of the titanium etching solution according to any one of the above embodiments, and sequentially adding the deionized water, the inorganic base, the hydrogen peroxide, the stabilizer, the copper surface protective agent, and the accelerator in the etching tank, and stirring for 5-10 min when adding the raw materials.

[0050] The application also provides an application of the titanium etching solution in the surface treatment of a semiconductor ceramic plate, which uses the titanium etching solution according to any one of the above embodiments to perform etching treatment on the titanium layer on the surface of the semiconductor ceramic plate. Specifically, the pH value of the titanium etching solution during the etching treatment is 9.5-11.5, the temperature of the etching treatment is constant temperature titanium removal at 50-60℃, and the time of the etching treatment is 30-100 s.

[0051] Example 1

[0052] A titanium etching solution comprises the following raw materials by weight:

[0053] 2.0% of an inorganic base;

[0054] 5.0% of hydrogen peroxide;

[0055] 0.6% of a stabilizer;

[0056] 0.1% of a copper surface protective agent;

[0057] 0.3% of an accelerator;

[0058] and the balance of deionized water.

[0059] Specifically, the inorganic base is sodium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is ethylenediamine and n-octylamine at a weight ratio of 0.5:1; the copper surface protective agent is 4-amino tetrazole; and the accelerator is tripropylene glycol methyl ether.

[0060] The preparation method of the titanium etching solution specifically comprises the following steps:

[0061] (1) adding 300-400 ml of deionized water into an etching tank;

[0062] (2) adding an inorganic base into the etching tank in step (1) and stirring for 3-5 min;

[0063] (3) adding hydrogen peroxide with a concentration of 30% into the etching tank in step (2) and stirring for 5-10 min;

[0064] (4) adding a stabilizer into the etching tank in step (3) and stirring for 5-10 min;

[0065] (5) adding a copper surface protective agent into the etching tank in step (4) and stirring for 5-10 min;

[0066] (6) adding an accelerator into the etching tank in step (5) and stirring for 5-10 min;

[0067] (7) finally, adding deionized water into the etching tank until 1 L and stirring for 5-10 min;

[0068] It should be noted that the preparation method of the titanium etching solution in the subsequent examples and comparative examples is the same as that in the present example.

[0069] Example 2

[0070] A titanium etching solution comprises the following raw materials by weight:

[0071] 2.2% of an inorganic base;

[0072] 6.0% of hydrogen peroxide;

[0073] 0.7% of a stabilizer;

[0074] 0.2% of a copper surface protective agent;

[0075] 0.4% of an accelerator; and

[0076] the balance of deionized water.

[0077] Specifically, the inorganic base is potassium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is cyclohexylamine; the copper surface protective agent is benzotriazole; and the accelerator is diethylene glycol methyl ether.

[0078] Example 3

[0079] A titanium etching solution comprising raw materials of the following weight components:

[0080] 2.5% of inorganic base;

[0081] 7.0% of hydrogen peroxide;

[0082] 0.7% of stabilizer;

[0083] 0.25% of copper surface protective agent;

[0084] 0.5% of accelerator;

[0085] and the balance of deionized water.

[0086] Specifically, the inorganic base is calcium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is n-octylamine and cyclohexylamine in a weight ratio of 1:1.2; the copper surface protective agent is benzotriazole and imidazole in a weight ratio of 08:0.2; and the accelerator is diethylene glycol methyl ether.

[0087] Example 4

[0088] A titanium etching solution comprising raw materials of the following weight components:

[0089] 3.0% of inorganic base;

[0090] 9.0% of hydrogen peroxide;

[0091] 0.8% of stabilizer;

[0092] 0.3% of copper surface protective agent;

[0093] 0.6% of accelerator;

[0094] and the balance of deionized water.

[0095] Specifically, the inorganic base is potassium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is olefin and its derivative and disodium ethylenediaminetetraacetate in a weight ratio of 1:1.5; the copper surface protective agent is methyl imidazole and imidazole in a weight ratio of 1:0.8; and the accelerator is diethylene glycol butyl ether and methyl ether eugenol in a weight ratio of 1:0.2, and specifically, the olefin and its derivative is furan-2-ketone type lactone.

[0096] Example 5

[0097] A titanium etching solution comprising raw materials of the following weight components:

[0098] 3.0% of inorganic base;

[0099] 10.0% of hydrogen peroxide;

[0100] 0.9% of stabilizer;

[0101] 0.3% of copper surface protective agent;

[0102] 0.6% of accelerator;

[0103] and the balance of deionized water.

[0104] Specifically, the inorganic base is sodium hydroxide; the concentration of hydrogen peroxide is 30%; the stabilizer is tetrasodium ethylenediaminetetraacetate; the copper surface protective agent is mercapto 2-mercapto benzimidazole and imidazole in a weight ratio of 1:0.2; the accelerator is 1,6-fructose diphosphate trisodium salt, and specifically, the accelerator is 1,6-fructose diphosphate trisodium salt 38099-82-0.

[0105] Comparative Example 1

[0106] A titanium etching solution includes the following raw materials by weight:

[0107] 1.8% of inorganic base;

[0108] 4.0% of hydrogen peroxide;

[0109] 0.5% of stabilizer;

[0110] 0.05% of copper surface protective agent;

[0111] 0.2% of accelerator;

[0112] and the balance of deionized water.

[0113] Specifically, the inorganic base is sodium hydroxide; the concentration of hydrogen peroxide is 30%; the stabilizer is diethylenetriamine; the copper surface protective agent is mercapto 2-mercapto benzimidazole; and the accelerator is tetramethylammonium hydroxide.

[0114] Comparative Example 2

[0115] A titanium etching solution includes the following raw materials by weight:

[0116] 1.8% of inorganic base;

[0117] 4.0% of hydrogen peroxide;

[0118] 0.5% of stabilizer;

[0119] 0.05% of copper surface protective agent;

[0120] and the balance of deionized water.

[0121] Specifically, the inorganic base is sodium hydroxide; the concentration of hydrogen peroxide is 30%; the stabilizer is diethylene triamine; the copper surface protective agent is mercapto 2-mercapto benzimidazole.

[0122] Comparative Example 3

[0123] A titanium etching solution includes the following raw materials by weight:

[0124] 1.8% of inorganic base;

[0125] 4.0% of hydrogen peroxide;

[0126] 0.5% of stabilizer;

[0127] 0.05% of copper surface protective agent;

[0128] 0.2% of accelerator;

[0129] and the balance of deionized water.

[0130] Specifically, the inorganic base is potassium hydroxide; the concentration of hydrogen peroxide is 30%; the stabilizer is ethylenediaminetetraacetic acid disodium; the copper surface protective agent is methyl imidazole and imidazole in a weight ratio of 1:0.8; and the accelerator is diethylene glycol butyl ether and methyl ether eugenol in a weight ratio of 1:0.2.

[0131] Comparative Example 4

[0132] A titanium etching solution includes the following raw materials by weight:

[0133] 1.8% of inorganic base;

[0134] 4.0% of hydrogen peroxide;

[0135] 0.5% of stabilizer;

[0136] 0.05% of copper surface protective agent;

[0137] 0.2% of accelerator;

[0138] and the balance of deionized water.

[0139] Specifically, the inorganic base is potassium hydroxide; the concentration of hydrogen peroxide is 30%; the stabilizer is ethylenediaminetetraacetic acid disodium; the copper surface protective agent is methyl imidazole and imidazole in a weight ratio of 1:0.8; and the accelerator is diethylene glycol butyl ether and methyl ether eugenol in a weight ratio of 1:0.2.

[0140] Etching rate determination:

[0141] 1) Take a piece of double-sided titanium plate, place it in an oven at 105±5°C for 15 minutes, and cool it to room temperature in a desiccator;

[0142] 2) Weighing G1 (unit: gram, accurate to 2-3 decimal places) by balance;

[0143] 3) Passing the above titanium plate through the etching tank according to the set time or transmission speed, and recording the processing time T (min);

[0144] 4) Washing with secondary water, drying, and then placing in an oven at 105±5℃ for 15 minutes, and cooling to room temperature in a dryer;

[0145] 5) Weighing G2 (unit: gram, accurate to 2-3 decimal places) by balance;

[0146] 6) Measuring the area S of the test plate (the sum of the areas of both sides, unit: cm2)

[0147] 7) Calculation: etching rate (μm / min) = {(G1-G2) / (4.51×S×T)}×10000.

[0148] Etching factor determination:

[0149] 1) Taking a titanium sample plate that needs to be etched to form a circuit;

[0150] 2) Passing through the titanium etching tank section, washing with secondary water, and taking out from the drying section.

[0151] 3) Cutting a 2cm×3cm slice with a circuit from the plate in 2) above.

[0152] 4) Polishing the slice in 3) above using a grinding and polishing machine to polish the circuit edge surface.

[0153] 5) Measuring the values of a, b, and h under a 200x metallographic microscope.

[0154] 6) Calculation method: etching factor = 2h / (b-a), wherein the etching factor a represents the bottom copper width, b represents the upper copper line width, and h represents the copper thickness.

[0155] Under the same conditions, the titanium etching solution of the present application examples 1-5 and the comparative examples respectively etches the titanium layer of ceramic plates of the same specification.

[0156] The test results are shown in Table 1.

[0157] Table 1, test result data table of examples 1-5 and comparative examples

[0158]

[0159] As shown in Table 1, the titanium etching liquid of the present application can quickly etch the titanium layer by adding stabilizers, copper surface protectants and accelerators, and will not attack the copper surface and the ceramic substrate, has good etching effect, etching rate is higher than 0.1 μm / min (i.e. 1000 Å / min), and has high etching factor. Specifically, the comparison of the comparative example 1 and the examples 1-5 shows that the raw material ratio of the present application can meet the basic requirements of etching; the comparison of the comparative example 1 and the comparative example 2 shows that the addition of the accelerator has a great influence on the etching efficiency of the titanium etching liquid; the comparison of the data of the example 1 and the comparative example 3, and the comparison of the example 4 and the comparative example 4 show that the etching efficiency and the etching factor of the titanium etching liquid can be changed by adjusting the raw material ratio, and the etching efficiency and the etching factor of the titanium etching liquid can be improved by appropriately increasing the raw material ratio. As can be seen from the examples 1-5 and the comparative examples 1-4, the titanium etching liquid of the present application uses potassium hydroxide, olefin and its derivatives, disodium ethylenediaminetetraacetate, methyl imidazole, imidazole, diethylene glycol butyl ether and methyl ether eugenol as raw materials, and has the best etching effect by virtue of the compounding effect. The etching process is mild and controllable, the etching liquid is easy to clean, the consumption is small, the wastewater treatment of the present application is easy, the present application is friendly to the environment, the cost is low, and the present application does not contain fluorine. The etching effect of the example 4 on the ceramic plate is the best, and meets various requirements.

[0160] In summary, the present application provides a titanium etching liquid, a preparation method thereof and application in the surface treatment of a semiconductor ceramic plate, and an inorganic alkali-hydrogen peroxide system titanium etching liquid is prepared, which can effectively and quickly remove the titanium layer on the surface of a semiconductor ceramic plate, does not corrode the silicon nitride, aluminum nitride, silicon oxide and aluminum oxide ceramic substrate, does not erode the copper layer, has good etching uniformity, fast etching rate and high etching factor, and can be applied to the etching treatment of the titanium surface treatment process of a semiconductor ceramic plate. The present application provides a titanium etching liquid, realizes mild etching conditions, reduces the damage to the surface of a semiconductor ceramic plate, and ensures the performance and reliability of a semiconductor device.

[0161] The above description is only the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation in the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A titanium etching solution, characterized in that the titanium etching solution comprises the following raw materials by weight components: 3.0% of potassium hydroxide; 9.0% of hydrogen peroxide; wherein the concentration of the hydrogen peroxide is 30%; 0.8% of a stabilizer; wherein the stabilizer is 1:1 by weight ratio of: 1.5 olefins and derivatives thereof and disodium ethylenediaminetetraacetate; 0.3% of a copper surface protectant; wherein, The copper surface protective agent is methyl imidazole and imidazole in a weight ratio of 1:0.8; 0.6% of an accelerator; wherein the accelerator is diethylene glycol butyl ether and methyl ether eugenol in a weight ratio of 1:0.2; and a balance of deionized water.

2. A method for preparing a titanium etching solution, characterized by, Specifically comprising the following steps: Providing raw material components of the titanium etching solution of claim 1, sequentially adding the deionized water, inorganic base, hydrogen peroxide, stabilizer, copper surface protective agent and accelerator in the etching tank, and stirring for 5-10 min when adding the raw materials.

3. Use of a titanium etching solution for surface treatment of a semiconductor ceramic plate, characterized in that, Using the titanium etching solution of claim 1 to perform etching treatment of the titanium layer on the surface of the semiconductor ceramic plate.

4. The use of the titanium etching solution according to claim 3 in the surface treatment of a semiconductor ceramic plate, characterized in that, The temperature of the etching treatment is constant temperature titanium removal at 50-60°C, and the time of the etching treatment is 30-100 s.

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