Silicon carbide transistor opens the door to extreme-environment electronics

Silicon carbide transistors enable extreme-temperature semiconductor operations, making them widely used in industry. But junction-based devices have long struggled with poorly controlled threshold voltages and high-temperature leakage at higher temperatures, making their performance unpredictable and less efficient in those extreme environments. Kaneko et al. created a new transistor that solves both problems, paving the way for accurately designed, low-leakage silicon carbide circuits in high-temperature applications.

The authors fabricated the transistors by selective ion implantation into 4H-SiC, a common type of silicon carbide. Two variants were built: one on a semi-insulating substrate to measure how the design could control threshold voltages, and another that minimized current leakage through a layer that electrically isolated the transistor from its environment. They demonstrated precise threshold-voltage control, with only a 0.1-V deviation at 400 C, and low leakage suppression at high temperatures. At 600 C, the measured leakage value was an order of magnitude lower than conventional devices at 400 C. Notably, the team found this residual leakage was set by silicon carbide’s intrinsic thermal-generation limit, indicated by an activation energy near half the material’s bandgap.

“By placing the transistor’s gate below the channel, rather than above as in conventional designs, we absorb the distortion caused by ion channeling during implantation,” author Mitsuaki Kaneko said.

The transistor’s ability to operate in conditions in which the device is normally off is a prerequisite for some low-power logic circuits. Future work will include redesigning the device for this capability, as well as measuring its long-term stability and testing it as part of an integrated system.

Source: “Over 600°C operation of ion-implantation-based SiC bottom-gate JFETs,” by Mitsuaki Kaneko, Shunya Shibata, and Tsunenobu Kimoto, APL Electronic Devices (2026). The article can be accessed at https://doi.org/10.1063/5.0346734 .

This paper is part of the Electronic Devices with High Operating Temperature (> 500 °C) Collection, learn more here .