Why Quartz Baths Are Used in the Wafer Cleaning Process

The cleaning of silicon wafers during semiconductor manufacturing uses harsh chemicals to remove deposits from the silicon’s surface.

The semiconductor manufacturing process includes multiple steps, each of which may require cleaning the silicon wafer before or after the production process segment. Highly corrosive chemicals (like sulfuric acid and hydrogen peroxide) are used to remove impurities.

For effective cleaning of the silicon wafer:

·   The contaminants and impurities should be completely removed.
·         The container used should be of an impervious nature.
·         There needs to be tight control of the bath temperature.

Without controlling these three factors during the wafer cleaning process, manufacturing such as diffusion will be affected. Even the smallest remaining particle of contaminant can obstruct an electrical connection and affect electrical characteristics. The resulting semiconductor device will be unreliable or defective.

Baths made from high purity quartz don’t react with the corrosive chemicals used in semiconductor manufacturing and are inert as a source of contamination. Thus, a high-quality quartz bath is an ideal container for the semiconductor wafer cleaning process.

During the cleaning process, the silicon wafers are immersed in a chemical within the quartz bath. The baths may be heated depending on the cleaning process, to a given temperature for a certain time period, and chemicals may be re-circulated. The chemicals in the quartz bath remove organic impurities from the surface of the wafers. Then the step of rinsing and drying the wafers will follow. The wafers are then immersed in a mixture of hydrochloric acid and hydrogen peroxide, where the metallic impurities are removed. After that, the wafers will be subjected to processing steps.

Quartz baths, such as Modutek series QFa re-circulating baths, facilitate reliable cleaning of silicon wafers.

If you have questions about how quartz baths are used in the wafer cleaning process, please read the complete article “Why Quartz Baths Are Used in the Wafer Cleaning Process”. Contact Modutek at 866-803-1533 to discuss your specific wafer cleaning needs.