The Process of Cleaning a Wafer

A double side polish wafer is in demand for applications that have specific flatness requirements. Examples are microelectronics, MEMS, and semiconductor applications. Double side polish wafers are also thinner compared to regular wafers. Therefore, they are faster, more powerful, and advantageous to chip stack technology.One of the main reasons why double side polish wafers are thinner is because they go through several polishing processes. However, these processes can cause contaminants and unwanted materials to accumulate on the surface of the wafer, compromising their quality. Cleaning the wafers will help get rid of the unwanted materials and guarantee high-quality wafers.

What is the Process of Cleaning Double Side Polish Wafers?

Resist Stripping

Resist stripping or photoresist stripping removes unwanted photoresist layers on the surface of a double side polish wafer. Its goal is to get rid of any photoresist material present on the wafer as fast as possible. Quickly doing it will prevent the chemicals used in the process from damaging the resist's surface materials.Resist Stripping can be categorized into the following:

• Organic Stripping – this method uses organic strippers to break down the form of the resist layer. Phenol-free or low-phenol organic strippers are the most widely-used organic strippers available today.
• Inorganic Stripping – this method uses an oxidizing-type stripper to remove photoresist layers from non-metalized wafers. It is also suitable for eliminating hard-to-remove resists.
• Dry Stripping – this method uses plasma etching equipment to remove the photoresist. It is considered a safer approach than wet etching since it does not cause any metal ion contamination. Therefore, it also causes fewer pollution issues.

Chemical Removal of Film Contaminants

Chemical cleaning is the most effective way of removing contaminant material films that are chemically bonded on the surface of the wafer. There are several forms of chemical cleaning, depending on the type of film contaminants that need to remove and from which kind of surface. Typically, chemical cleaning involves a series of acid and rinse baths.

Looking for a Double Side Polish Wafer?

These are just a few of the methods used to clean wafers. Furthermore, there are several others that you need to know about! Wafer cleaning plays an essential role in ensuring a high-quality double side polish wafer. So, at Wafer World, we offer a wide range of good-quality wafers at a reasonable price. Contact us for inquiries!