Real-Time Whole Wafer Thermal Imaging for Semiconductor Process Monitoring

This program will develop a whole wafer sensor for in situ monitoring and control of temperature during thermally assisted film processes such as rapid thermal processing (RTP), Metallorganic shemical vapor depostition (MOCVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), and chemical vapor deposition (CVD). This sensor will provide spatially resolved whole-wafer measurements of temperature, emissivity and film stack properties in real-time, from a model based analysis of thermal radiance images. Preliminary studies suggest that the sensor could have accuracies in the range of plus or minus 1 degree Celsius. Exploiting recently available commercial infrared imaging technology, the hardware for the proposed system will be extremely compact and will provide high performance measurement capability from a single small infrared window with line-of-sight access to the wafer surface. In Phase I, a prototype sensor will be constructed for whole wafer monitoring of temperature and emissivity. The system will be tested on a variety of wafers in a test reactor equipped with a pyrometer and a Fourier transform infrared (FT-IR) sensor for measurement validation. A preliminary design will be developed in Phase I for an instrument capable of performing the measurements continuously and in real-time, with throughputs high enough for applications in RTP. In Phase II, the real-time system design will be completed, and the real-time prototype sensor will be constructed and demonstrated on a variety of process platforms.