High Ion/Ioff ratio 4H-SiC MISFETs with stable operation at 500°C using SiO2/SiNx/Al2O3 gate stacks

In this work, 4H-SiC lateral metal-insulator-semiconductor field-effect transistors (MISFETs) were demonstrated to operate up to 50 degrees C with a high on/off current ratio (over 10(9)). A low off-state current of 3.6 x 10(-9) mA/mm at 500 degrees C was obtained in SiC MISFET with a ring structure. The MISFETs with SiO2/SiNx/Al2O3 gate dielectric stack showed minimum subthreshold swings of 155 and 240 mV/dec at room temperature and 500 & DEG;C, respectively, indicating good thermal stability of this gate dielectric stack on SiC. An interface trap density of 1.3 x 10(11) cm(-2) eV(-1) at E - E-V = 0.2 eV was extracted from the Capacitance-Voltage (CV) measurements at room temperature, which confirms excellent dielectric interface. The electron mobility increases with increasing temperature and reaches 39.4 cm(2)/V s at 500 degrees C. These results indicate that SiC MISFETs with triple layer dielectrics and ring structure have a high potential in extreme-temperature electronics.

Automated summary

In this study, SiC MISFETs with a triple layer dielectric stack and a ring structure were demonstrated to have a high potential in extreme-temperature electronics. These MISFETs operated up to 50 degrees C with a high on/off current ratio and a low off-state current at elevated temperatures. The gate dielectric stack showed good thermal stability and excellent dielectric interface. The electron mobility also increased with temperature, indicating the suitability of these MISFETs for extreme environments.