Design and research of normally-off β-Ga₂O₃/4H-SiC heterojunction field effect transistor

Ga₂O₃ is difficult to achieve p-type doping, which further hinders the development of Ga₂O₃-based power devices and is not conducive to the development of new devices with high power density and low power consumption. This paper expounds a β-Ga₂O₃/4H-SiC heterojunction lateral metal–oxide–semiconductor field-effect transistor (HJFET), which can make better use of the characteristics of PN junction by adding p-doped SiC in the channel region. Compared with the conventional devices, the threshold voltage of the heterojunction metal–oxide–semiconductor field-effect transistor (MOSFET) is greatly improved, and normally-off operation is realized, showing a positive threshold voltage of 0.82 V. Meanwhile, the off-state breakdown voltage of the device is up to 1817 V, and the maximum transconductance is 15.3 mS/mm. The optimal PFOM is obtained by simulating the thickness, length and doping of the SiC in each region of the epitaxial layer. This structure provides a feasible idea for high performance β-Ga₂O₃ MOSFET.