Improved Ultrahigh Upper Gate 4H-SiC MESFET with Serpentine Channel Structure

An improved ultrahigh upper gate 4H-SiC MESFET (UU-MESFET) with serpentine channel structure (UUSC-MESFET) was proposed. With the implement of the serpentine channel, the channel electric field and the gate depletion layer have been more modulated compared with the UU-MESFET. The simulations show that the breakdown voltage and the drain saturation current of UUSC-MESFET are improved by 13.6%, 12% than those of UU-MESFET and by 44.5%, 23% than those of the double-recessed structure (DR-MESFET). By introducing a recessed channel layer, the proposed structure has an improvement of 27.3%, 81.3% in the out maximum power density compared with that of the UU-MESFET and DR-MESFET, respectively. In the meanwhile, the proposed structure possesses smaller gate-source capacitance, which results in better RF characteristics. Therefore the proposed structure has a superior electrical characteristic and performance.