TW202043184A - Semiconductor bump process stripping liquid causing no damage on metals including dimethyl sulfoxide, ethylene glycol, tetramethyl ammonium hydroxide and a metal protective agent - Google Patents

Abstract

A semiconductor bump process stripping liquid causing no damage on metals mainly includes dimethyl sulfoxide with a concentration range of 65% to 85%; ethylene glycol with a concentration range of 0.5% to 30%; tetramethyl ammonium hydroxide with a concentration range of 1% to 3%; and a metal protective agent with a concentration range of 0.5% to 1.5%. Therefore, under the bath concentration of 100% (full solution), the operating temperature of 80 ± 5 DEG C, and the photoresist stripping time of 30 ± 10 min (strip), the stripping liquid can be added or replaced quantitatively according to the number of processed pieces, the thickness of the photoresist, and the area, so as to achieve a success rate of realizing good stripping of the semiconductor bump process without causing damages on metals including tin, copper, aluminum, etc.

Description

Metal-free semiconductor bumping process stripping liquid

The present invention relates to the technical field of film stripping liquid, and particularly refers to a film stripping liquid for semiconductor bump manufacturing processes that does not damage metal.

Semiconductor bumping manufacturing is a comprehensive industry integrating optics, electricity, chemistry, machinery, materials, and management science. A variety of chemicals and special raw materials must be used in its complex manufacturing process.

The film removal treatment is an important part of the related process. However, the composition of the existing conventional film removal solution is still not perfect. The film removal treatment time is long and the effect is poor when applied, and it will damage the semiconductor bumping process. Metal, which leads to a decrease in mass production yield, is its main disadvantage.

The purpose of the present invention is to provide a metal-free semiconductor bump process stripping solution, which mainly includes:

Dimethyl Sulfoxide (Dimethyl Sulfoxide), with a concentration range of 65% to 85%;

Ethylene Glycol, with a concentration range of 0.5% to 30%;

Tetra Methyl Ammonium Hydroxide (Tetra Methyl Ammonium Hydroxide), with a concentration range of 1% to 3%, and;

Metal Protective Agent (Metal Protective Agent) concentration range component percentage 0.5% to 1.5%;

In this way, the concentration of the bath under construction is 100% (full solution); the operating temperature is 80 ± 5°C; the stripping time is 30 ± 10min (strip);

The liquid medicine can be added or replaced quantitatively according to the number of slices, the thickness of the photoresist and the area.

When applied, the advantages of the present invention compared with the prior art are: the present invention is a kind of multifunctional stripping liquid with long liquid life and strong effect. It is specially designed for dry film (photoresist) stripping liquid. In addition to effectively speeding up the dry film stripping of the semiconductor bump process, it can also achieve the effect of cleaning the metal surface of the semiconductor bump process, especially under high temperature operation. It can attack and damage the metal on the semiconductor bumping process, so it can achieve a good stripping success rate for the semiconductor bumping process without damaging metals including tin, copper, aluminum, etc.

In order to have a further understanding and understanding of the composition and application functions of the present invention, examples are given in conjunction with the drawings, and the detailed description is as follows.

As shown in Figures 1 to 3, a non-damaging metal semiconductor bumping process stripping liquid provided by the present invention mainly includes:

Dimethyl Sulfoxide (Dimethyl Sulfoxide), with a concentration range of 65% to 85%;

Ethylene Glycol, with a concentration range of 0.5% to 30%;

Tetra Methyl Ammonium Hydroxide (Tetra Methyl Ammonium Hydroxide), with a concentration range of 1% to 3%, and;

Metal Protective Agent (Metal Protective Agent) concentration range component percentage 0.5% to 1.5%;

Therefore, the composition of the stripping liquid has a bath concentration of 100% (full solution); the operating temperature is at least 80 ± 5℃; the stripping time is at least 30 ± 10min (strip); and it can achieve good stripping for the semiconductor bump process The success rate, and can not harm the metal including tin, copper, aluminum and so on.

In a preferred implementation, the stripping liquid of the composition can be further quantitatively added or replaced according to the number of semiconductor bumps to be stripped, the thickness of the photoresist, and the area.

In a preferred implementation, the CAS NO. of the dimethyl sulfide is 67-68-5; the CAS NO. of the ethylene glycol is 107-11-1; the tetramethylammonium hydroxide The chemical registration number CAS NO. is 75-59-2, and the chemical registration number CAS NO. of the metal protective agent is 87-99-0.

For better implementation, when building the bath, a tank made of stainless steel or PP polypropylene can be used, together with a stainless steel, quartz or titanium heating tube, and an exhaust fan with an air volume of 100~500 CFM, and in the pipeline The air volume adjustment baffle can be installed to achieve the best peeling effect.

Traditionally, the removal liquid is easy to damage tin (metal): mainly because tin is an amphoteric metal, it is easy to form +2 and +4 oxidation states. The chemical properties of tin have the following characteristics:

(1) At room temperature, tin will not be oxidized by air or react with water, and is used to plate some metal surfaces to prevent corrosion.

(2) When heated at high temperature, tin reacts with oxygen, halogen, sulfur and other non-metals to form oxides, halides and sulfides.

Sn+2X2 → SnX4 (X=F, Cl, Br, I) Sn+S → SnS Sn+2S → SnS2 Sn+O2 → SnO2

(3) Tin can be dissolved in alkaline solution to generate stannous acid:

Sn+2NaOH+ 2H2O → Na2[Sn(OH)4″＞+H2

Generally, tin is slightly affected by water corrosion, but it is easily corroded by acids and alkalis. When oxygen is present in the solution, tin becomes a catalyst, accelerating chemical corrosion. Tin can form SnO2 after heating in the air, and SnO2 is weakly acidic. It can directly react with chlorine and oxygen. In dilute acid, it can replace hydrogen ions. Being in the middle of metal and non-metal, it has the characteristics of both.

As shown in Figure 1, the stripping liquid of the present invention has a metal protection principle, which is to add a special (tin) metal protection agent to the formula. It is mainly an alkyl compound. The basic principle is that the organic compound of the alkyl can form a coordination bond with the electron of the tin metal and form an alkyl-tin complex.

Among them, the chain alkyl groups are attracted to each other through Van der Waals force, thus forming a protective layer on the surface of tin. This protective layer has high heat resistance and high decomposition temperature, and is resistant to oxidation during high temperature operation. And thermal shock.

As shown in Figure 2, from the comparison of the etching of tin metal with the traditional stripping liquid of the present invention, it can be seen that the stripping liquid of the present invention does have a good protective effect and will not harm the tin metal.

Above, only the application of the present invention on tin metal testing is used as an example for description, but in fact, the present invention does not harm the type of metal and is not limited to this.

For example, as shown in Figure 3, the preferred implementation, wherein the stripping liquid of this composition is at a temperature of 80°C, and the metal etching rate Å/min is less than 3 for copper, less than 1, and less than 2 for aluminum.

As shown in Figure 4, it is a test diagram of the metal resistance of the stripping solution of the present invention to tin and copper. It was tested in a beaker at 80°C, soaked for 30 minutes and then deliberately picked up the wafer and left in the air for 3 minutes to confirm that it would not cause Copper is oxidized, tin metal is not attacked, only tin metal plating surface roughness problems, no other abnormalities were found. As shown in Figure 5, the aluminum pad product will not be damaged even if it is immersed for 120 minutes at 80°C for metal chemical resistance.

When applied, the advantages of the present invention compared with the prior art are: the present invention is a kind of multifunctional stripping liquid with long liquid life and strong effect. It is specially designed for dry film (photoresist) stripping liquid. In addition to effectively speeding up the dry film stripping of the semiconductor bump process, it can also achieve the effect of cleaning the metal surface of the semiconductor bump process, especially under high temperature operation. It can attack and damage the metal on the semiconductor bumping process, and can achieve a good stripping success rate for the semiconductor bumping process without damaging metals including but not limited to tin, copper, and aluminum.

However, the above are only preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention; therefore, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the description of the invention , Should still fall within the scope of the invention patent.

Figure 1 is a chemical reaction diagram of the stripping solution of the present invention to protect tin metal. Figure 2 is a comparison diagram of the etching of tin metal between the present invention and the traditional stripping liquid. Figure 3 is a comparison diagram of the etching of metal copper, tin, and aluminum by the stripping liquid of the present invention. Figure 4 is a test diagram of the metal resistance of the stripping liquid of the present invention to tin and copper. Figure 5 is a test diagram of the metal resistance of the stripping liquid of the present invention to the aluminum pad.

Claims (5)

A non-damaging semiconductor bumping process film stripping liquid mainly includes: Dimethyl sulfide, with a concentration range of 65% to 85%; Ethylene glycol, the concentration range of the component percentage is 0.5% to 30%; Tetramethylammonium hydroxide, with a concentration range of 1% to 3% component percentage, and; Metal protective agent, with a concentration range of 0.5% to 1.5%; Therefore, the bath concentration under construction is 100% (full solution); the operating temperature is at least 80 ± 5°C; the stripping time is at least 30 ± 10 minutes, and the semiconductor bumping process can be stripped well without harming tin , Copper, aluminum metal. For example, the metal-free semiconductor bumping process stripping liquid described in the first item of the scope of patent application, wherein the composition of the stripping liquid is further based on the number of semiconductor bumps to be stripped, the thickness and area of the photoresist Quantitative addition or replacement. As described in the first item of the scope of patent application, the metal-free semiconductor bumping process stripping liquid, in which the chemical registration number of the dimethyl sulfide, CAS NO. is 67-68-5; the chemical registration of the ethylene glycol The CAS NO. is 107-11-1; the CAS NO. of the tetramethylammonium hydroxide is 75-59-2, and the CAS NO. of the metal protective agent is 87-99-0 . For example, the non-damaging metal semiconductor bumping process stripping liquid described in the first item of the scope of patent application, in which the bath material is further used in the bath building, stainless steel or PP polypropylene, and is equipped with stainless steel, quartz or titanium The heating pipes, and the exhaust fan with air volume 100~500 CFM, and the air volume adjustment baffle is installed in the pipeline. As mentioned in the first item of the scope of patent application, the metal-free semiconductor bumping process stripping liquid, wherein the metal etch rate of the stripping liquid at a temperature of 80℃ is Å/min less than 3, tin less than 1, and aluminum less than 2.

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