Exhaust gas monitoring: New window into semiconductor processing

In situ Fourier transform and nondispersive infrared spectrometry have been successfully coupled into many semiconductor processing systems. These inf rared sensors provide the real-time data required to develop and optimize a process, transfer a process between tools, monitor and control it, determi ne etch and chamber clean end points, and generate fault detection and clas sification information. Infrared absorption spectroscopy allows the process gas to be probed without requiring a plasma or sensing element to interact with the process. Most molecules absorb infrared light with a characterist ic "fingerprint," providing qualitative information for component identific ation. Here we describe alpha and beta tests with tool manufacturers to mon itor and control semiconductor processes.