High-temperature applications of SIMOX technology

High-temperature operation of regular bulk CMOS integrated circuits is usually limited to approximately 200 deg C because of the increase of the junction leakage currents, the drift of the threshold voltage, the degradation of the mobility in the transistors, and thermally-induced latchup. In addition to these strictly device-related parameter variations, other degradation mechanisms are raising reliability issues when high-temperature operation is to be considered. These are: increased electromigration phenomena in aluminum lines, stress and corrosion in the package, etc... While the latter problems can be solved by using tungsten as an interconnect metal and by using appropriate packaging materials, the drift of device parameters with temperature is a problem having no solution as long as classical bulk silicon MOS technology is employed