9361145 Worthington In response to customer demand for accurate temperature measurement of Si and GaAs, Thermionics propose; to use a new temperature sensor to measure the temperature Si and GaAs wafers above 800 C and as high as 1100 C. The technique uses a system called (DRS) Diffuse Reflectance Spectroscopy. The principal behind DRS is that it measures the changing band gap energy as a function of temperature. The sensor uses a light source located out of the growth camber that is modulated so that it can be detected in the presence of other light sources, such as the heater source. Preliminary measurements of Ga using DRS show smooth variation of the optical wavelengths associated with the absorption threshold between 4K and 1000K. The laws of Physics and thermodynamics suggest that band gap measurements can be made above these temperatures. In Phase I, Thermionics expects to develop techniques and improvements to the DRS sensor technology to measure temperature above 1100 C.
