There are numerous ways and techniques to clean a thin silicon wafer. Cleaning guarantees that a wafer is free from contaminants and other foreign materials as it goes through the wafer production process. Because there are different types of contaminants with different properties, wafers need to go through different kinds of wafer cleaning. Here are some different types of thin silicon wafer cleaning:
Resist Stripping
Photoresist stripping is the elimination of unwanted photoresist layers from the thin silicon wafer. This has to be done quickly to avoid the chemical used in the process from harming the wafer. There are three types of resists stripping:
Organic Stripping- uses organic chemicals to disintegrate the structure of the resist layer. The most common type of organic strippers is the phenol-based type. But because phenol has a short shelf life and is difficult to dispose of, phenol-free organic strippers are now the preferred type.
Inorganic Stripping- Also known as oxidizing-type strippers are used to eliminate photoresist from non-metalized wafers and other stubborn resists.
Dry Stripping- Dry stripping involves the use of a plasma etching equipment to dry etch or eliminate photoresist. What’s good about dry stripping is that it’s safer; there are no metal-ion contamination, fewer pollution issues, and a decreased chance of attachment for underlying substrate layers.
Insoluble particulates that contaminate the wafers are also one of the common problems. There are two types of techniques frequently used to eliminate particulates in wafers:
Mechanical Scrubbing- The process involves a rotating brush, hydroplanes, and solvent applied on the wafer. The solvent displaces the particles on the wafer surface.
Ultrasonic Scrubbing- This technique focuses on the ultrasonic energy that loosens and evicts particles. This technique is great except that it causes mechanical damage to the substrate layers.
Where to Buy a Thin Silicon Wafer?
Wafer cleaning is so important to produce a high-quality thin silicon wafer. At Wafer World, you can get high-quality wafers at the best price possible! Call us for inquiries or purchase wafers online!
