High Temperature Silicon Carbide CMOS Integrated Circuits

Abstract

The wide band-gap of Silicon Carbide makes it a material suitable for IC's [1] operating up to 450°C. The maximum operating temperature achieved will depend on the transistor technology selected, interconnect metallisation and device packaging. This paper describes transistor and circuit results achieved in SiC CMOS technology, where the major issue addressed is the gate dielectric performance. N and p-channel MOSFET structures have been demonstrated operating at temperatures up to 400°C Test circuits including simple logic cells, ring oscillators, operational amplifiers and gate drive circuits have been fabricated and the characteristics of ring oscillators are presented here. Floating capacitor structures have also been fabricated for use in future analogue and mixed signal circuits. This technology will be initially applied in applications including signal conditioning for sensors and control of SiC based power switching devices, where the high temperature capability will match that of the SiC power devices which are now becoming commercially available.