Characteristic Study Of Silicon Carbide MOSFET

Compared with Silicon,Silicon carbide(SiC)is regarded attractive for high-power switching application and circuit design under high operation temperature due to its large bandgap(3.26eV),high thermal conductivity,and high electric breakdown field.SiC power chips can operate at higher voltages,frequencies and temperatures,which will eliminate most of the power losses in electricity conversion.Nowadays,many leading semiconductor companies and research institutions have made great progress on industrialization of SiC MOSFET.At present,the majority of commercial SiC MOSFET are n-channel planar vertical structure.As foreseeing great potential applications of SiC MOSFET,several companies have lanced updated products.Meanwhile,the extensive application of SiC MOSFET is limited by gate interface states in planar vertical SiC MOSFET and the resulting low channel mobility.The pre-theoretical research in SiC MOSFET structure design and experimental method are always accomplished by simulation modeling,however,there exists quite a gap between experimental and simulation results,the difference can be explained as a lack of accurate models of interface state and carrier mobility in inversion layer.Based on the problems of industry development and theoretical research in SiC MOSFET,a systematic study on SiC MOSFET is conducted in the paper,including the followings:This work investigates electrical characteristics and stability of three generations of SiC MOSFET with temperature varying from-160 ? t0 200 ?.In particular,temperature-dependence of threshold voltage and on-resistance,as well as the impact of gate bias on on-resistance have been compared and analyzed.It is found that threshold voltage shows smaller temperature dependence from the 1st generation to the 3rd generation,a plausible reason of which is a lower density of interface traps at the SiO2/SiC interface.This work investigates a physical model of studied 4H-SiC MOSFET based on the structure dimension data of device.The research is focusing on establishing temperature-dependent SiC MOSFET mobility model and SiO2/SiC interface state model.The simulation results match the experimental characteristics well.