Double-agent type copper etching liquid

Abstract

The invention belongs to the technical field of electronic chemicals, and particularly discloses a double-dosage-form copper etching solution which comprises a solution A and a solution B. The solution A comprises, by mass, 1-5% of copper salt, 2-16% of inorganic acid, 2-18% of organic alkali, 0.01-2% of surfactant and the balance water. Compared with the solution A, the solution B only replaces the copper salt with the organic acid with the corresponding molar content, other raw materials are consistent, and organic alkali is added to adjust the pH to 6.2-6.8; in the etching process, only the solution A is used, and when the etching life of the solution A reaches the limit, the solution B is repeatedly added to prolong the etching life. According to the double-dosage-form copper etching solution containing the solution A and the solution B, the etching life of the solution A is continuously updated by adding the solution B, the service life of the etching solution is prolonged, and redundant technological processes are reduced, so that the production cost is saved, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductors, and in particular relates to a double-dosage type copper etching solution. Background Art

[0002] Metal interconnects in semiconductor manufacturing, advanced packaging, and display panels are generally formed by etching the photoresist pattern after the mask pattern is developed using the corresponding copper etching solution. Currently, the most commonly used copper etching solution in semiconductor manufacturing, advanced packaging, and display panels is the hydrogen peroxide series single-dose copper etching solution. However, hydrogen peroxide is easy to decompose to produce flammable gas oxygen, and it is accompanied by a large amount of heat during decomposition, which can easily cause accidents such as combustion or even explosion. The single-dose solution also needs to be replaced during use, which is not conducive to the company's safe production and continuous production. At the same time, the hydrogen peroxide series etching solution has a short service life and a high production cost. Therefore, it is very important to develop a safe, stable, efficient, and long-etching dual-dose copper etching solution.

[0003] In order to formulate a dual-type copper etching solution with high safety, stability and service life, and to make the copper etching solution adapt to the development of semiconductor manufacturing, advanced packaging and display industries and meet process requirements, it is urgent to develop a safe, efficient and long-life dual-type copper etching solution. Summary of the invention

[0004] The invention provides a dual-type copper etching solution, which comprises a dual-type copper etching solution containing a solution A and a solution B, and continuously updates the etching life of the solution A by adding the solution B, thereby extending the service life of the etching solution, reducing redundant process flows, thereby saving production costs and improving production efficiency.

[0005] The technical solution of the present invention is to provide a double-type copper etching solution, which includes a solution A and a solution B; Liquid A contains the following ingredients by mass percentage: 1-5% copper salt, 2-16% inorganic acid, 2-18% organic base and 0.01-2% surfactant, and the balance is water; Compared with solution A, solution B only replaces copper salt with organic acid of corresponding molar content, and the other raw materials are the same, and an organic base consistent with solution A is added to adjust the pH to 6.2-6.8; During the etching process, only liquid A is used first. When the etching life of liquid A reaches its limit, liquid B is repeatedly added to extend its etching life.

[0006] Furthermore, the copper salt is one or more of copper oxalate, copper tartrate, and copper glycinate.

[0007] Furthermore, the inorganic acid is nitric acid, phosphoric acid and / or sulfuric acid, and its mass content is 2-16%.

[0008] Furthermore, the organic base is prepared by mixing a pyrazole compound and an amino alcohol compound in a mass ratio of 1 to 5:1.

[0009] Furthermore, the pyrazole compound is one or more of 3-aminopyrazole, 4-methylpyrazole and N-methyl-3-aminopyrazole.

[0010] Furthermore, the amino alcohol compound is one or more of 3-aminopropanol, 3-(methylamino)-1-propanol or 1,3-diamino-2-propanol.

[0011] Furthermore, the surfactant is one or more of fatty acid methyl ester ethoxylate sodium sulfonate, lauryl sulfate ammonium salt and hydroxyethyl sulfonate ammonium salt.

[0012] Furthermore, the organic acid is oxalic acid, tartaric acid and / or glycine corresponding to the copper salt.

[0013] Furthermore, after the Cu ion concentration of solution A reaches 12000 ppm, solution B is added to adjust the Cu ion concentration in the copper etching solution to 8000-12000 ppm.

[0014] The present invention has the following beneficial effects: The copper etching solution of the present invention is composed of a solution A and a solution B, wherein the solution A is composed of a copper salt, an inorganic acid, a surfactant, an organic base and deionized water, and the solution B is composed of an organic acid, an inorganic acid, a surfactant, an organic base and deionized water. In the process of etching copper and its alloys by using the etching solution, after the etching life of the solution A reaches a limit, the solution B can be added to continuously update the etching life of the solution A, thereby extending the service life of the etching solution, reducing redundant process flows, thereby saving production costs and improving production efficiency. DETAILED DESCRIPTION

[0015] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0016] A dual-agent copper etching solution, the etching solution comprising liquid A and liquid B, during the etching process, only liquid A is used first, and when the etching life of liquid A reaches a limit, liquid B is repeatedly added to extend its etching life; Specifically, liquid A contains the following ingredients by mass percentage: 1-5% copper salt, 2-16% inorganic acid, 2-18% organic base and 0.01-2% surfactant, and the balance is water; Compared with solution A, solution B has only copper salt replaced by organic acid with corresponding molar content, and the other raw materials are the same, and an organic base is added to adjust the pH to 6.2-6.8.

[0017] In some cases, the copper salt content is preferably 1-2%, and the copper salt may be one or more of copper oxalate, copper tartrate, and copper glycinate.

[0018] In some cases, the amount of inorganic acid is preferably 2-8%; the inorganic acid is nitric acid, phosphoric acid and / or sulfuric acid, and more preferably a mixture of nitric acid and phosphoric acid / or sulfuric acid in a mass ratio of 1-3.

[0019] In some cases, the amount of organic base is preferably 5-14%; the organic base is prepared by mixing a pyrazole compound and an amino alcohol compound in a mass ratio of 1 to 5:1. A more preferred mass ratio is 3:1 to 5:1.

[0020] In some cases, the dosage of the pyrazole compound is preferably 6-12%; the pyrazole compound is one or more of 3-aminopyrazole, 4-methylpyrazole and N-methyl-3-aminopyrazole.

[0021] In some cases, the amount of the amino alcohol compound is preferably 1-5%; the amino alcohol compound is one or more of 3-aminopropanol, 3-(methylamino)-1-propanol or 1,3-diamino-2-propanol.

[0022] In some cases, the amount of surfactant used is preferably 0.1-1%; the surfactant is one or more of sodium fatty acid methyl ester ethoxylate sulfonate, ammonium lauryl sulfate and ammonium hydroxyethyl sulfonate.

[0023] In some cases, the organic acid is oxalic acid, tartaric acid and / or glycine corresponding to the copper salt.

[0024] The following provides specific examples and comparative examples for detailed description. The specific formula is shown in Table 1, where % is mass percentage.

[0025] Table 1

[0026] When preparing the etching solution in the above embodiments and comparative examples, deionized water is first added, and magnetic stirring is turned on (500r / min), and inorganic acid and copper salt are added in sequence and fully mixed, and then a surfactant is added, and finally an organic base is added, and the temperature of the solution is controlled below 25°C, and the copper etching solution is obtained by mixing (the steps for preparing solution B are the same as those for solution A, and finally an organic base is added to adjust the pH to 6.2 to 6.8).

[0027] The obtained etching solution was used for etching test: Take 1000ml of copper etching solution in each beaker and heat it to stabilize at 35±0.2℃. Then cut the structure to be etched into 20*20mm size and immerse it completely in the etching solution and shake it slightly until the metal copper on the structure is etched away and the structure becomes partially transparent. Record the time required for the structure to become transparent, which is the etching endpoint time, and calculate the etching rate accordingly. Subsequently, gradually add copper powder with a diameter of 80-100nm to the etching solution, turn on magnetic stirring (speed 500r / min), wait for it to react for 1h, and the copper powder in the solution is completely dissolved, then etch the structure, and record the etching rate and experimental phenomena of the etching solution on copper at different copper ion concentrations. When the Cu ion concentration in solution A reaches 12000ppm, solution B is added to reduce the Cu ion concentration in the copper etching solution to 8000ppm. Then it is etched to 12000ppm, and then solution B is added. This cycle is repeated until the etching solution fails (precipitation occurs in the solution or the etching rate changes by more than 20%) or the cycle exceeds 30 times. The number of cycles in which solution B is updated is recorded.

[0028] The data obtained from the above test are shown in Table 2 below.

[0029] Table 2

[0030] In Comparative Examples 1 and 2, the oxalic acid in solution B is not the molar amount corresponding to the copper salt in solution A, but is added less or more accordingly, resulting in unstable pH of the etching solution after solution B is added to solution A, and the number of cycles is only 5 and 2 times.

[0031] In Comparative Example 3, the pH value of Solution B was adjusted without using an organic base. After Solution B was circulated and renewed 8 times, the etching rate of the solution decreased by more than 20%.

[0032] The acid concentration in Example 4 is too low, and the ratio of the pyrazole compound to the amino alcohol compound in Examples 9 and 10 is too low or too high, which will affect the effect of the etching solution, and the initial life of the etching solution cannot reach 12000ppm.

[0033] The above embodiments describe the preferred implementation of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other manner. These simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims. .

Claims

1. A dual-type copper etching solution, characterized in that: The etching solution includes liquid A and liquid B; Liquid A contains the following ingredients by mass percentage: 1-5% copper salt, 2-16% inorganic acid, 2-18% organic base and 0.01-2% surfactant, and the balance is water; Compared with solution A, solution B only replaces copper salt with organic acid of corresponding molar content, and the other raw materials are the same, and an organic base consistent with solution A is added to adjust the pH to 6.2-6.8; During the etching process, only liquid A is used first. When the etching life of liquid A reaches its limit, liquid B is repeatedly added to extend its etching life.

2. The double-component copper etching solution according to claim 1, characterized in that: The copper salt is one or more of copper oxalate, copper tartrate and copper glycinate.

3. The double-component copper etching solution according to claim 1, characterized in that: The inorganic acid is nitric acid, phosphoric acid and / or sulfuric acid, and the mass content thereof is 2-16%.

4. The double-component copper etching solution according to claim 1, characterized in that: The organic base is prepared by mixing pyrazole compounds and amino alcohol compounds in a mass ratio of 1 to 5:

1.

5. The double-component copper etching solution according to claim 4, characterized in that: The pyrazole compound is one or more of 3-aminopyrazole, 4-methylpyrazole and N-methyl-3-aminopyrazole.

6. The double-component copper etching solution according to claim 4, characterized in that: The amino alcohol compound is one or more of 3-aminopropanol, 3-(methylamino)-1-propanol or 1,3-diamino-2-propanol.

7. The dual-component copper etching solution according to any one of claim 1, characterized in that: The surfactant is one or more of fatty acid methyl ester ethoxylate sodium sulfonate, lauryl alcohol sulfate ammonium salt and hydroxyethyl sulfonate ammonium salt.

8. The dual-component copper etching solution according to any one of claims 1 to 7, characterized in that: The organic acid is oxalic acid, tartaric acid and / or glycine corresponding to the copper salt.

9. The dual-component copper etching solution according to any one of claims 1 to 7, characterized in that: When the Cu ion concentration of solution A reaches 12000ppm, solution B is added to adjust the Cu ion concentration in the copper etching solution to 8000-12000ppm.

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