Titanium etching solution, preparation method thereof and application of titanium etching solution in surface treatment of semiconductor ceramic plate

Abstract

The invention relates to a titanium etching solution, a preparation method thereof and application of the titanium etching solution in surface treatment of a semiconductor ceramic plate. The titanium etching solution comprises the following raw materials by weight: 1.8-3.0% of an inorganic base; 4.0 to 10.0% of hydrogen peroxide; 0.5%-1.0% of a stabilizing agent; 0.05 to 0.3 percent of a copper surface protective agent; 0.2 to 0.6 percent of an accelerator; and the balance of deionized water. The preparation method of the titanium etching liquid specifically comprises the following steps that the raw materials of the components are provided, and the deionized water, the inorganic base, the hydrogen peroxide, the stabilizer, the copper surface protective agent and the accelerator are sequentially added into an etching tank and stirred for 5-10 min. When the titanium etching solution provided by the invention is applied to surface treatment of a semiconductor ceramic plate, titanium is removed at a constant temperature of 50-60 DEG C during etching treatment, and the time of etching treatment is 30-100 seconds. The titanium etching solution provided by the invention is good in etching uniformity, high in etching rate and high in etching factor.

Description

Technical Field

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

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

[0003] However, in the later forming process of the ceramic plate, part of the copper and titanium metals must be etched away to form the circuit. At present, the semiconductor ceramic plate etching production line mainly adopts horizontal line and spray mode for etching. This equipment usually includes a tank filled with etching liquid and one or more nozzles for spraying the etching liquid onto the ceramic plate. During operation, the ceramic plate is placed horizontally on the conveyor belt, and the movement of the conveyor belt makes the ceramic plate pass through the spray area. The etching time of titanium is usually between 60-120 seconds.

[0004] There is a Chinese patent (application publication number CN117904632A) that discloses a semiconductor titanium etching solution, which is composed of: Hydrogen peroxide: 8-25 parts; Organic polyphosphonic acid and its derivatives: 1-20 parts; Polycarboxylic acid ammonium salt: 1-7 parts; Phosphate ether compounds: 0.5-2 parts; Ultrapure water: 40-65 parts.

[0005] However, the maximum etching rate of this etching solution in immersion mode is only 900 Å / min, which can only be used in semiconductor chip manufacturing processes and cannot meet the needs of semiconductor ceramic substrate production processes. In the horizontal production of ceramic substrates, this etching solution is difficult to meet production standards, which seriously affects production efficiency.

[0006] Therefore, an important issue facing the field of semiconductor ceramic substrate production 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 of the invention

[0007] In the prior art, there is an urgent need to provide a titanium etching solution that can improve production efficiency while ensuring etching quality. Therefore, the present invention provides a titanium etching solution and a preparation method thereof and an application in surface treatment of semiconductor ceramic plates to solve the above problems.

[0008] To achieve the above object, in a first aspect, the present invention provides a titanium etching solution comprising the following raw materials by weight: 1.8-3.0% inorganic alkali; 4.0-10.0% hydrogen peroxide; 0.5-1.0% stabilizer; 0.05-0.3% copper surface protective agent; 0.2-0.6% accelerator; and the balance is deionized water.

[0009] In one implementation, the inorganic base includes one or a combination of sodium hydroxide, potassium hydroxide and calcium hydroxide.

[0010] In one implementation, the stabilizer includes one or a combination of ethylenediamine, cyclohexylamine, n-octylamine, monoethanolamine, triethanolamine, disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, olefins and derivatives thereof.

[0011] In one implementation, the copper surface protective agent includes one or a combination of 4-aminotetrazolyl, benzotriazole, methylimidazole, mercapto-mercaptobenzimidazole and imidazole.

[0012] In one implementation, the accelerator includes one or a combination of tripropylene glycol methyl ether, diethylene glycol butyl ether, diethylene glycol methyl ether, methyl ether, ethyl ether, trisodium 1,6-diphosphate fructose and methyl ether eugenol.

[0013] In one implementation, the titanium etching solution includes the following raw materials by weight: 3.0% potassium hydroxide; 9.0% hydrogen peroxide; wherein the concentration of the hydrogen peroxide is 30%; 0.8% of a stabilizer; wherein the stabilizer is olefins and their derivatives and disodium ethylenediaminetetraacetate in a weight ratio of 1:1.5; 0.3% copper surface protective agent; wherein the copper surface protective agent is methylimidazole and imidazole in a weight ratio of 1:0.8; 0.6% accelerator; wherein the accelerator is diethylene glycol butyl ether and methyl ether eugenol in a weight ratio of 1:0.2; and the balance is deionized water.

[0014] In a second aspect, the present invention also provides a method for preparing a titanium etching solution, which specifically comprises the following steps: providing the raw material components of the titanium etching solution described in any one of the above items, sequentially adding the deionized water, inorganic base, hydrogen peroxide, stabilizer, copper surface protective agent and accelerator into an etching tank, and stirring for 5 to 10 minutes when adding the raw materials.

[0015] In a third aspect, the present invention further provides an application of a titanium etching solution in surface treatment of a semiconductor ceramic plate, wherein any one of the above-mentioned titanium etching solutions is used to etch a titanium layer on the surface of the semiconductor ceramic plate.

[0016] In one implementation, the etching process is performed at a temperature of 50 to 60° C. and the etching process lasts for 30 to 100 seconds.

[0017] Beneficial effects: The present invention provides a titanium etching solution and a preparation method thereof and an application in the surface treatment of semiconductor ceramic plates, thereby preparing an inorganic alkali-hydrogen peroxide system titanium etching solution, providing a titanium etching solution that can effectively and quickly remove the titanium layer on the surface of the semiconductor ceramic plate, while not corroding silicon nitride, aluminum nitride, silicon oxide, and aluminum oxide ceramic substrates, and will not corrode the copper layer. It has good etching uniformity, fast etching rate, and high etching factor, and can be suitable for etching treatment in the titanium surface treatment process of semiconductor ceramic plates. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. 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 invention. In this specification, the schematic representation of the above terms is not necessarily for the same embodiment or example. Moreover, the technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0019] The present invention provides a titanium etching solution, which comprises the following raw materials by weight: 1.8-3.0% inorganic alkali; 4.0-10.0% hydrogen peroxide; 0.5-1.0% stabilizer; 0.05-0.3% copper surface protective agent; 0.2-0.6% accelerator; and the balance is deionized water.

[0020] Among them, the inorganic alkali can adjust the liquid environment to alkaline, and the addition of hydrogen peroxide is the main oxidant for the titanium layer, which plays the main role in etching the titanium metal, and the alkaline liquid environment can enhance the bite of the titanium metal. The addition of the stabilizer can maintain the stability of the etching solution and prevent the decomposition or failure of hydrogen peroxide during use. The copper surface protective agent is to inhibit the corrosion of the copper metal by the liquid, and protect the copper metal from only biting the titanium metal. The accelerator is used to adjust the etching speed and etching depth of the etching solution to achieve uniform etching.

[0021] Specifically, the inorganic base includes one or a combination of sodium hydroxide, potassium hydroxide and calcium hydroxide. The concentration of the hydrogen peroxide is 30%. The hydrogen peroxide provided by the present invention is activated under alkaline conditions, and the presence of heavy metal ions will cause the hydrogen peroxide to catalytically decompose prematurely. The stabilizer can react with the active oxygen ions (O 2- ) to undergo a chemical reaction, thereby reducing the concentration of active oxygen ions and slowing down the decomposition rate of hydrogen peroxide.

[0022] Specifically, the stabilizer includes one or a combination of ethylenediamine, cyclohexylamine, n-octylamine, monoethanolamine, triethanolamine, disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, olefins and their derivatives.

[0023] Specifically, the copper surface protective agent includes one or a combination of 4-aminotetrazole, benzotriazole, methylimidazole, mercapto 2-mercaptobenzimidazole 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 corrosion of the copper surface.

[0024] Specifically, the accelerator includes one or a combination of tripropylene glycol methyl ether, diethylene glycol butyl ether, diethylene glycol methyl ether, methyl ether, ethyl ether, trisodium salt of 1,6-diphosphate fructose and methyl ether eugenol. The accelerator also has an amplification effect: it cleans dirt and contaminants on the surface of the plate, increases surface tension, improves the cleanliness of the plate, enhances the contact effect between the titanium etching solution and the surface of the plate, and improves the performance of the titanium etching solution.

[0025] Furthermore, the stabilizer and the copper surface protective agent can form a complex with these metal ions to prevent them from catalyzing the decomposition of hydrogen peroxide. The copper surface protective agent imidazole can react with the olefin and its derivatives in the stabilizer to generate 3-onium salt zwitterions, which then react with another molecule of dienophile nucleophilic addition to generate C-2 cyclized products, preventing the decomposition of hydrogen peroxide at high temperatures. The addition of an accelerator can increase the oxidation effect of hydrogen peroxide on titanium metal, achieving the effect of rapid corrosion of titanium.

[0026] The present invention also provides a method for preparing a titanium etching solution, which specifically comprises the following steps: providing the raw material components of the titanium etching solution described in any one of the above, sequentially adding the deionized water, inorganic alkali, hydrogen peroxide, stabilizer, copper surface protective agent and accelerator into an etching tank, and stirring for 5 to 10 minutes when adding the raw materials.

[0027] The present invention also provides an application of a titanium etching solution in the surface treatment of a semiconductor ceramic plate, wherein any of the titanium etching solutions described above is used to etch the titanium layer on the surface of the semiconductor ceramic plate. Specifically, during the etching treatment, the pH value of the titanium etching solution is 9.5 to 11.5, the etching treatment temperature is a constant temperature titanium stripping of 50 to 60° C., and the etching treatment time is 30 to 100 seconds.

[0028] Example 1 A titanium etching solution comprising the following raw materials by weight: 2.0% inorganic base; 5.0% hydrogen peroxide; 0.6% stabilizer; 0.1% copper surface protective agent; 0.3% accelerator; and the balance is deionized water.

[0029] Specifically, the inorganic base is sodium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is ethylenediamine and n-octylamine in a weight ratio of 0.5:1; the copper surface protective agent is 4-aminotetrazole; and the accelerator is tripropylene glycol methyl ether.

[0030] Wherein, the preparation method of the titanium etching solution specifically comprises: (1) Add 300~400ml of deionized water into the etching tank; (2) Add an inorganic base to the etching tank in step (1) and stir for 3 to 5 minutes; (3) Add 30% hydrogen peroxide into the etching tank in step (2) and stir for 5 to 10 minutes; (4) Add stabilizer to the etching tank in step (3) and stir for 5 to 10 minutes; (5) Add copper surface protective agent to the etching tank in step (4) and stir for 5 to 10 minutes; (6) Add accelerator to the etching tank in step (5) and stir for 5 to 10 minutes; (7) Finally, add deionized water to the etching tank to 1L and stir for 5-10 minutes; It should be noted that the preparation methods of the titanium etching solutions in the subsequent examples and comparative examples are the same as the preparation method of this example.

[0031] Example 2 A titanium etching solution comprising the following raw materials by weight: 2.2% inorganic base; 6.0% hydrogen peroxide; 0.7% stabilizer; 0.2% copper surface protective agent; 0.4% accelerator; and the balance is deionized water.

[0032] 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.

[0033] Example 3 A titanium etching solution comprising the following raw materials by weight: 2.5% inorganic base; 7.0% hydrogen peroxide; 0.7% stabilizer; 0.25% copper surface protective agent; 0.5% accelerator; and the balance is deionized water.

[0034] 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.

[0035] Example 4 A titanium etching solution comprising the following raw materials by weight: 3.0% inorganic alkali; 9.0% hydrogen peroxide; 0.8% stabilizer; 0.3% copper surface protective agent; 0.6% accelerator; and the balance is deionized water.

[0036] Specifically, the inorganic base is potassium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is olefins and their derivatives and disodium ethylenediaminetetraacetate in a weight ratio of 1:1.5; the copper surface protective agent is methylimidazole and imidazole in a weight ratio of 1:0.8; the accelerator is diethylene glycol butyl ether and methyl ether eugenol in a weight ratio of 1:0.2, and specifically, the olefins and their derivatives are furan-2-one type lactone.

[0037] Example 5 A titanium etching solution comprising the following raw materials by weight: 3.0% inorganic alkali; 10.0% hydrogen peroxide; 0.9% stabilizer; 0.3% copper surface protective agent; 0.6% accelerator; and the balance is deionized water.

[0038] Specifically, the inorganic base is sodium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is tetrasodium ethylenediaminetetraacetic acid; the copper surface protective agent is thiol 2-mercaptobenzimidazole and imidazole in a weight ratio of 1:0.2; the accelerator is trisodium fructose 1,6-diphosphate, and specifically, the accelerator is trisodium fructose 1,6-diphosphate 38099-82-0.

[0039] Comparative Example 1 A titanium etching solution comprising the following raw materials by weight: 1.8% inorganic base; 4.0% hydrogen peroxide; 0.5% stabilizer; 0.05% copper surface protective agent; 0.2% accelerator; and the balance is deionized water.

[0040] Specifically, the inorganic base is sodium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is diethylenetriamine; the copper surface protective agent is mercapto 2-mercaptobenzimidazole; and the accelerator is tetramethylammonium hydroxide.

[0041] Comparative Example 2 A titanium etching solution comprising the following raw materials by weight: 1.8% inorganic base; 4.0% hydrogen peroxide; 0.5% stabilizer; 0.05% copper surface protective agent; and the balance is deionized water.

[0042] Specifically, the inorganic base is sodium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is diethylenetriamine; and the copper surface protective agent is mercapto 2-mercaptobenzimidazole.

[0043] Comparative Example 3 A titanium etching solution comprising the following raw materials by weight: 1.8% inorganic base; 4.0% hydrogen peroxide; 0.5% stabilizer; 0.05% copper surface protective agent; 0.2% accelerator; and the balance is deionized water.

[0044] Specifically, the inorganic base is sodium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is ethylenediamine and n-octylamine in a weight ratio of 0.5:1; the copper surface protective agent is 4-aminotetrazole; and the accelerator is tripropylene glycol methyl ether.

[0045] Comparative Example 4 A titanium etching solution comprising the following raw materials by weight: 1.8% inorganic base; 4.0% hydrogen peroxide; 0.5% stabilizer; 0.05% copper surface protective agent; 0.2% accelerator; and the balance is deionized water.

[0046] Specifically, the inorganic base is potassium hydroxide; the concentration of the hydrogen peroxide is 30%; the stabilizer is disodium ethylenediaminetetraacetic acid; the copper surface protective agent is methylimidazole 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.

[0047] Etching rate determination: 1) Take a double-sided titanium plate, place it in an oven at 105±5℃ for 15 minutes, and cool it to room temperature in a desiccator; 2) Weigh G1 on a balance (unit: grams, please be accurate to 2 to 3 decimal places); 3) Pass the titanium plate through the etching tank at the set time or transmission speed, and record the processing time T (min); 4) After secondary water washing and drying, place in an oven at 105±5℃ for 15 minutes and cool to room temperature in a dryer; 5) Weigh G2 on a balance (unit: grams, please be accurate to 2 to 3 decimal places); 6) Measure the area S of the test board (the sum of the areas of both sides, unit: cm2) 7) Calculation: Etching rate (μm / min) = {(G1-G2) / (4.51×S×T)}×10000.

[0048] Etching factor determination: 1) Take a titanium sample that needs to be etched with circuits; 2) Pass through the titanium etching cylinder section, undergo secondary water washing, and take out from the drying section.

[0049] 3) Cut a piece of circuit board with length and width = 2cm × 3cm from the board mentioned in 2).

[0050] 4) Use a grinding and polishing machine to grind and polish the edges of the slices prepared in 3).

[0051] 5) Measure the values ​​of a, b, and h on the slices polished in 4) above under a 200x metallographic microscope.

[0052] 6) Calculation method: Etching factor = 2h / (ba), where etching factor a represents the bottom copper width, b represents the upper copper line width, and h represents the copper thickness.

[0053] Under the same conditions, the titanium etching solutions of Example 1 to the comparative example of the present invention respectively etched the titanium layer of ceramic plates of the same specifications.

[0054] The test results are shown in Table 1.

[0055] Table 1. Test results of Examples 1 to 5 and Comparative Examples As can be seen from Table 1, the titanium etching solution of the present invention can quickly etch the titanium layer by adding a stabilizer, a copper surface protective agent and an accelerator, and will not attack the copper surface and the ceramic substrate, has a good etching effect, an etching rate higher than 0.1μm / min (i.e., 1000Å / min), and a high etching factor. Specifically, compared with Examples 1 to 5, the comparative example 1 provided by the present invention shows that the ratio of its raw materials can meet the basic requirements of etching; at the same time, it can be obtained from the comparison between Comparative Example 1 and Comparative Example 2 that the addition of the accelerator has a greater impact on the etching efficiency of the titanium etching solution; by comparing the data of Example 1 and Comparative Example 3, and the comparison between Example 4 and Comparative Example 4, the etching efficiency and etching factor of the titanium etching solution can be changed by adjusting the raw material ratio, and the etching efficiency and etching factor of the titanium etching solution can be improved by appropriately increasing the raw material ratio. It can be seen from Examples 1 to 5 and Comparative Examples 1 to 4 that the titanium etching solution provided by the present invention, by selecting potassium hydroxide, olefins and their derivatives, disodium ethylenediaminetetraacetate, methylimidazole, imidazole, diethylene glycol butyl ether and methyl ether eugenol as raw materials, exerts its compounding effect to achieve the best etching effect. The etching process is gentle and controllable, the etching solution is easy to clean, the consumption is small, and the wastewater treatment of the present invention is easy, environmentally friendly, low cost, and fluorine-free. And Example 4 has the best etching effect on ceramic plates and meets various requirements.

[0056] In summary, the present invention provides a titanium etching solution and a preparation method thereof and an application in the surface treatment of semiconductor ceramic plates, thereby preparing an inorganic alkali-hydrogen peroxide system titanium etching solution, providing a titanium etching solution that can effectively and quickly remove the titanium layer on the surface of the semiconductor ceramic plate, while not corroding silicon nitride, aluminum nitride, silicon oxide, and aluminum oxide ceramic substrates, and not corroding the copper layer. The etching has good uniformity, fast etching rate, and high etching factor, and can be applied to the etching treatment of the titanium surface treatment process of semiconductor ceramic plates. The present invention provides a titanium etching solution to achieve mild etching conditions, reduce damage to the surface of the semiconductor ceramic plate, and ensure the performance and reliability of semiconductor devices.

[0057] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the specification of the present invention, or directly or indirectly applied in other related technical fields, is also included in the patent protection scope of the present invention.

Claims

1. A titanium etching solution, characterized in that: The raw materials include the following weight components: 1.8-3.0% inorganic alkali; 4.0-10.0% hydrogen peroxide; 0.5-1.0% stabilizer; 0.05-0.3% copper surface protective agent; 0.2-0.6% accelerator; and the balance is deionized water.

2. The titanium etching solution according to claim 1, characterized in that The inorganic base includes one or a combination of sodium hydroxide, potassium hydroxide and calcium hydroxide.

3. The titanium etching solution according to claim 1, characterized in that The stabilizer includes one or a combination of ethylenediamine, cyclohexylamine, n-octylamine, monoethanolamine, triethanolamine, disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, olefins and derivatives thereof.

4. The titanium etching solution according to claim 1, characterized in that The copper surface protective agent includes one or a combination of 4-aminotetrazolyl, benzotriazole, methylimidazole, 2-mercaptobenzimidazole and imidazole.

5. The titanium etching solution according to claim 1, characterized in that: The accelerator includes one or a combination of tripropylene glycol methyl ether, diethylene glycol butyl ether, diethylene glycol methyl ether, methyl ether, ethyl ether, trisodium 1,6-diphosphate fructose and methyl ether eugenol.

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

7. A method for preparing a titanium etching solution, characterized in that: The specific steps include: Provide the raw material components of the titanium etching solution according to any one of claims 1 to 6, add the deionized water, inorganic base, hydrogen peroxide, stabilizer, copper surface protective agent and accelerator into the etching tank in sequence, and stir for 5 to 10 minutes when adding the raw materials.

8. Application of titanium etching solution in surface treatment of semiconductor ceramic plates, characterized in that: The titanium etching solution according to any one of claims 1 to 5 is used to etch the titanium layer on the surface of the semiconductor ceramic plate.

9. The use of the titanium etching solution according to claim 7 in surface treatment of semiconductor ceramic plates, characterized in that: The temperature of the etching process is a constant temperature titanium stripping process at 50 to 60° C., and the time of the etching process is 30 to 100 seconds.

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