550 ∘C Integrated Logic Circuits using 6H-SiC JFETs

This letter reports the design, fabrication, and electrical characteristics of inverter, NAND, and NOR logic circuits using 6H-silicon carbide (SiC) depletion-mode junction field-effect transistors. All circuits function with high performance at temperatures from 25 °C to 550 °C. The core inverter has an outstanding dc characteristic transfer function with a steep slope, including a gain of >; -20 up to 500 °C, and a logic threshold that is well centered in the logic swing. NOR and NAND gates were likewise tested in this temperature range, and dynamic characteristics are presented. This SiC technology provides a platform for applications demanding reliable digital circuits at temperatures higher than 300 °C, well beyond the capability of silicon technology.