In-Situ Chemical Monitoring in Semiconductor Fabrication Chemical Supplies

Abstract

Problem 

In-coming chemical quality has been left to the chemical suppliers. Semiconductor fabricators have very limited or no capability to detect problems with process chemistries from their suppliers. This is to say that poor chemical quality is discovered through in line test data or poor e-sort performance. Chemical quality is assumed to be what has been sent from the supplier and is typically documented through a certificate of analysis. Changes than can and do occur during in-house handling are disregarded and not monitored Historically speaking the risk from suppliers is low. Documented mishaps for out of spec material shipments are extremely rare. In fact the semiconductor industry in general insists on suppliers with a superior quality history and a robust quality program. However, these quality programs are not perfect and there have been isolated events. Events that resulted from human error within the fabrication facility are not very well documented, but those that have been have resulted in significant losses in product, production time and in some cases process equipment damage. Once the chemical has been containerized and shipped there is very little quality control. Factors such as human error in container handling and equipment failure at the distribution point are not accounted for.

Objective 

Therefore, the product (the wafers) is exposed to any potential chemical related problems. It became obvious ...