Hi There is a process for CMOS call RAD hardening. It is a process of exposing the CMOS to radiation for a period of time. It reduces the efficiency of the transistors but they don't degrade as fast ( comparatively ) once this is done. As far as solid state goes, silicon is a limiter. Other semiconducting materials can work at higher temperatures. Toyota has worked out a way to produce large quantities of defect free silicon-carbide. This can be used to make transistors that can be run at several hundred degrees C. This is of course interesting to them because they like to have high power transistors for electric cars. Another material that hasn't been used to much is diamond. This is one of the best material to make transistors from since it has such good thermal properties. There are still a lot of processing problem to work out for this to be of much use. They already have the ability to create diamond films. Dwight