4.87 kV SiC MOSFET Using HfSiO_x/SiO₂ Gate Dielectrics Combined with PN Pillars

A novel structure of a silicon carbide (SiC) double-trench metal oxide semiconductor field-effect transistor (DTMOSFET) is proposed using a hafnium silicate (HfSiO_x ) dielectric combined with PN pillars. Moreover, it has been characterized using Atlas TCAD Silvaco 2D simulations, and offers a very high breakdown voltage of 4879 V, which is due to the PN pillars under the N-drift layer altering the electric field distribution and HfSiO_x dielectric that diminishes the impact ionization. The proposed DTMOSFET achieves a transconductance (g_m) and drain current (I_D) of 7 mA/mm and 780 µS/mm, respectively. In addition, the simulated results show the cut-off frequency, f_{T =} 1.28 GHz, and maximum frequency, f_max = 10.5 GHz. In addition, the peak electric field observed near the gate edge is 0.93 MV/cm. Moreover, the proposed DTPNH-MOSFET shows 11% improvement in breakdown voltage when compared to the breakdown voltage of conventional DTMOSFET. Therefore, the DTPNH-MOSFET shows a superior performance over other SiC MOSFETs and is a suitable device for future high-power electronics.