Development of CMOS technology for smart power applications in silicon carbide.

摘要

Silicon carbide (SiC) is a wide bandgap semiconductor with a very high breakdown field and an excellent high temperature stability. SiC can also be thermally oxidized to form device quality oxides. Because of these features, SiC is an ideal material for high-power and high-temperature devices. The objective of this research is to develop a CMOS technology in 6H-SiC for smart power applications. Smart power technology offers power devices with built-in self protection circuitry, on-chip control circuitry, and an interface to external logic circuits. CMOS circuits for such applications must be stable at high temperatures, have adequate threshold voltages for operation with supply voltage of 10V or lower, and have fabrication processes which are compatible with power device processes. A 6H-SiC CMOS process utilizing an implanted p-well process is developed for integration with power DiMOSFET. The process resulted in NMOSFETs with threshold voltage of 3.3V and an effective channel mobility of around 20 cm{dollar}sp2{dollar}/Vs, and PMOSFETs with threshold voltage of {dollar}-{dollar}4.2V and an effective channel mobility of around 7.5 cm{dollar}sp2{dollar}/Vs. The first CMOS digital circuits in 6H-SiC to operate on a single 5V power supply at temperatures up to 300{dollar}spcirc{dollar}C have been fabricated using this technology.