JPH06302691A - Processing method for semiconductor wafer - Google Patents

Abstract

PURPOSE:To avoid contamination of a wafer due to adhesive of an adhesive tape and an environmental contamination due to processing. CONSTITUTION:The method for processing a semiconductor wafer comprises the steps of bonding an adhesive tape formed by combining a base material 1 of a water soluble film for back grinding, dicing the wafer and/or water soluble adhesive layer 2 to the wafer 4, mixing it, after the previous step is finished, with water to clean it, thereby dissolving or dispersing the material 1 and the layer 2 to be removed, and completely removing contaminant remaining on the surface of the wafer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a process for back grinding and dicing of a semiconductor wafer,
The present invention relates to a processing method using an adhesive tape for the purpose of protecting and / or fixing the wafer, or for both purposes.

[0002]

2. Description of the Related Art Conventionally, in the dicing process of a semiconductor wafer, as a pretreatment, a back grinding process for polishing the back surface of the wafer is performed, and then a "dicing" process for cutting the wafer into chips is performed, followed by expanding and picking up. Although a series of finishing processes such as cleaning, drying, and mounting are performed, the present situation is that the adhesive tape is used for supporting the wafer in this process. For example, in the back grinding step, the other surface is polished while fixing and protecting the surface not to be polished with an adhesive tape, and the tape is peeled off after the step is completed. In the dicing process, chips are cut while the back surface is fixed with an adhesive tape, expanded, and then picked up from the tape for mounting. In particular, when using an adhesive tape that uses a general-purpose adhesive, there is a problem that it remains on the surface of the wafer and causes contamination. To avoid this, in the expanding process,
At present, adhesives that can be cured by UV treatment are also used.

[0003]

[Problems to be Solved by the Invention]
After peeling, the wafer is cleaned, or after it is made into chips, it is cleaned using CFCs, chlorine-based organic solvents, and other various organic solvents. However, the use of these solvents causes problems such as destruction of the ozone layer, water pollution, and environmental pollution such as acid rain. Also, when UV curing is used, a UV irradiation device is required during the manufacturing process, which increases equipment costs and maintenance costs.Therefore, it is not possible to omit the cleaning process at all, which increases the cost burden. there were.

In view of the above problems, the present invention provides a safe and environmentally-unfriendly process by using only water washing so that the technology for treating wash drainage can be as simple as conventional techniques. The purpose is to

[0005]

In order to achieve the above object, in the method for processing a semiconductor wafer according to the present invention, one side of the semiconductor wafer is covered with an adhesive tape and peeled off in the back grinding step and the dicing step. However, a water-soluble material is used for the pressure-sensitive adhesive tape instead of the conventionally used material.

The adhesive tape used in the process of dicing a semiconductor wafer is generally used to form an adhesive layer 2 on one surface of a substrate 1 as shown in FIG. 1 and to protect the exposed surface of the adhesive layer 2. Until the last minute, the structure with the release film 3 attached is used. When using this for dicing,
First, the release film 3 is removed, and then the wafer 4 for dicing is fixed to the exposed surface of the adhesive layer 2 as shown in FIG. 2, and the exposed surface of the base material 1 is fixed to the jig 5. When using an adhesive tape for back grinding, work with a similar structure fixed in the same manner.

In order to impart water solubility to the pressure-sensitive adhesive tape having the above structure, it is necessary to use a water-soluble material for the base material 1 and the pressure-sensitive adhesive layer 2.

[0008] Generally, as a result of actual tests by the inventor as a water-soluble material that can be used as the substrate 1, synthetic resin-based materials such as polyvinyl alcohol and polyalkylene ether (polyalkylene oxide), gelatin, and polysaccharides. It was found that it can be used by making a film belonging to the category such as.

A water-soluble or water-dispersible adhesive is also applied to the adhesive formed on one side of the base material 1. The water-soluble adhesive is a category of adhesive known in the art and is widely used. You can use what you have.

[0010]

According to the present invention, in order to stick and use the adhesive tape having the above-described structure on one side of a semiconductor wafer, it is possible to perform back grinding or dicing and then mix and wash with water. Since both the base material and the adhesive layer can be easily dissolved or dispersed and removed, contaminants remaining on the wafer surface can be completely removed, and there is no need to give special consideration to wastewater treatment. .

[0011]

[Examples] Polyvinyl alcohol (Denka Popearl B-05 manufactured by Denki Kagaku Kogyo Co., Ltd.) was made into a liquid using water as a solvent, and a sheet having a thickness of 80 μ was formed by a casting method. Water-soluble adhesive on one side (Daicel Chemical Industry Co., Ltd.)
(Manufactured by Sebian A-886) was applied to obtain a pressure-sensitive adhesive sheet of this example. On the other hand, a radiation-curable pressure-sensitive adhesive was applied to a vinyl chloride film having a thickness of 80 μm to form a pressure-sensitive adhesive layer having a thickness of 25 μm to obtain a conventional pressure-sensitive adhesive sheet.

Next, a silicone wafer having a diameter of 15 cm was placed in the frame of a stainless steel frame, and the wafer and the frame were simultaneously attached and picked up from the pressure-sensitive adhesive sheet by a procedure such as dicing, expanding, etc., which is an ordinary process.

In this case, traces of the adhered matter remaining after the adhesive transfer from the adhesive sheet were seen on the wafer surface in both the example and the conventional type. However, by immersing the chips in water at 20 ° C. for 3 minutes. In the example, contaminants could be completely removed. However, in the case of the conventional type, there was almost no change from before washing with water, and the contaminants could not be removed.

Further, the pressure-sensitive adhesive sheet of this embodiment is 220 mm × 22
It was cut into 0 mm pieces, immersed in 500 cc of water, and slowly stirred at 20 ° C. for 3 minutes. As a result, it was completely dissolved and no residual solid matter was observed.

[0015]

Since the present invention employs the above-described processing method, it has the following effects.

In the method of processing a semiconductor wafer of the present invention, one side of the semiconductor wafer is covered with an adhesive tape and then peeled off in the back grinding step and the dicing step, which is conventionally used for the adhesive tape. Since a method of using a water-soluble material instead of the existing material has been introduced, it can be operated safely even after peeling the tape or without peeling, so safe operation and environmental damage can be done. Can be prevented. Since the cleaning wastewater generated by this process can be processed by the conventional treatment technology such as the activated sludge method, it is extremely advantageous in terms of production labor and cost burden.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a structure of an adhesive tape product used for processing a semiconductor wafer.

FIG. 2 is a vertical cross-sectional view showing a state where the adhesive tape product is fixedly used together with a wafer on a jig in the case of dicing.

[Explanation of symbols]

 1 Base material 2 Adhesive layer 3 Release film 4 Wafer 5 Jig

Claims (1)

[Claims] 1. A surface of a semiconductor wafer is covered with a pressure-sensitive adhesive tape, which is a combination of a water-soluble film and / or a water-soluble pressure-sensitive adhesive, in a processing step from surface treatment of a semiconductor wafer held by a pressure-sensitive adhesive tape to dicing. A method of processing a semiconductor wafer, which comprises performing a back grinding step and / or a dicing step by peeling.