The Sulfide Contamination Management in Circuit Probing FAB Clean Room Environment

Abstract Sulfur corrodes silver metal in a continuous reaction. This corrosion is also found in semiconductor industry processes for the application of silver into Backside Grinding & Backside Metal (BGBM). In this paper two experiments were conducted for the sulfide corrosion behavior in a Circuit Probing (CP) clean room environment. They were Mixed Flowing Gas (MFG) and clean room environment exposure test. The MFG test of this research was conducted in a testing chamber with temperature, relative humidity, and concentration of H2S were carefully controlled and monitored. The MFG test conditions included the test temperature of 25°C, relative humidity of 75 %, and H2S gas concentration of 10 ppb. And the MFG tests lasted for over 72 hours. The X-ray photoelectron spectroscopy (XPS) was used to analyze the elements composition and Ag2S film thickness of the MFG test samples. The second test of this research was the direct exposure experiment. The silicon samples deposited with appropriate silver layer thickness were exposed in CP fab clean room environment with H2S concentration well monitored. The XPS analysis results of the corresponding exposure test samples indicated that the Ag2S contamination would continue to develop and wouldn't saturate. This would be indicative for the management of Ag2S contamination control. The results of MFG and Exposure test were help for Ardentec to setup Ag2S corrosion methodology. All the managements were applied into daily operation of the BGBM semiconductor products.