We have developed a novel stand-alone diagnostic system that can analyze a semiconductor wafer surface in each process without introducing contamination. This allows us to analyze the relationship between chemical conditions and device properties.
A UHV (Ultra High Vacuum) wafer transfer chamber is used between the measuring apparatus and the semiconductor processes. The chamber vacuum system, which consists of a battery driven ion pump and a liquid N2 shroud, achieves a pressure of 2 × 10−8 Pa (corresponding to about 100 min. until one monolayer of contamination has been adsorbed).
Wafer transfer lines have been constructed between semiconductor vacuum processes, CVD (Chemical Vapor Deposition) and measuring instruments, ESCA (Electron Spectroscopy for Chemical Analysis) and TEM (Transmission Electron Microscope). Our results from ESCA and TEM showed measurements that carbon contamination and oxidation was suppressed.