Elevated Temperature Operation of 4H-SiC Nanoribbon Field Effect Transistors.

We fabricated 4H-SiC nanoribbon field effect transistors (FETs) of various channel thickness (tch) of 100~500 nm by a "top-down" approach, using a lithography and plasma etching process. We studied the dependence of the device transfer characteristics on the channel geometry. This demonstrated that fabricated SiC nanoribbon FETs with a tch of 100 nm show normally-on characteristics, and have a threshold voltage of -12 V, and a maximum transconductance value of 8.8 mS, which shows improved drain current degradation of the SiC nanoribbon FETs with tch = 100 nm at elevated temperature. This can be attributed to the improved heat dissipation, enhanced channel mobility, and together with widening of effective channel thickness depletion induced.