Monolithic Integration of High Temperature Silicon Carbide Integrated Circuits

Abstract

This paper deals with the design, the fabrication and the characterization of SiC ICs able to work at high temperature. The key SiC device is a planar MESFET specially designed for high temperature and high integration density. The other element required for integrating the basic cells library is a SiC resistor built in the same epilayer than the MESFET. Our preference for the MESFET is due to the already proved temperature stability of its Tungsten-Schottky barrier. The SPICE models of these two components are based on experimental measurements in the 25ºC-300ºC temperature range. The process technology setup is also analyzed, which contains three metal levels fully compatible with a standard CMOS technology. The digital library allows implementing multi-stage logic embedded in power management circuitry. The fabrication and the testing of the elementary logic gates library are also analyzed at high temperature and high frequencies. Furthermore, the standard CMOS topologies can be transferred to various Flip-Flops based on 4H-SiC MESFET basic logic gates. The multi-stage SiC ICs show a similar behavior as the logic gates at room and high temperatures, and at high frequency. The functionality of multi-stage SiC ICs has been proved.