Lateral depletion-mode 4H-SiC n-channel junction field-effect transistors (JFETs) are demonstrated to operate with well-behaved electrical characteristics at temperatures up to 600 • C in air. Ti/Ni/TiW metal stacks are used to form ohmic contacts to n-type 4H-SiC with specific contact resistance of 1.14 × 10 −3 cm 2 at 600 • C. The on/off drain saturation current ratio and intrinsic gain at 600 • C are 1.53 × 10 3 and 57.2, respectively. These results indicate that 4H-SiC JFETs can be used for extremely-high-temperature electronics applications.INDEX TERMS High-temperature electronics, junction field effect transistor (JFET), silicon carbide (SiC).

An electronic switching device that can achieve better performance than a MOSFET at low operating voltages is needed to mitigate the CMOS power crisis. The tunnel field effect transistor (TFET) can potentially meet this need. Germanium (Ge) is an attractive material to use in the source region of a silicon-based TFET, because it can provide for a small effective tunneling bandgap and hence large on-state tunneling current, and it is relatively easy to integrate into a CMOS process. Optimally designed Ge-source TFETs can achieve on/off current ratio well beyond the limit for MOSFETs at low operating voltages (<0.5 V), and hence are promising for future ultra-low-power digital integrated circuit applications.