A middle-recessed 4H-SiC metal semiconductor field effect transistors (MESFETs) with dual-channel layer was proposed and its electrical performances were studied by numerical device modeling. The higher doped lower-channel layer serves to increase the channel current while the lower doped upper-channel layer is used to improve the breakdown voltage. The thickness and doping concentration of the lower-channel layer are 0.08 µm and 3.8×1017 cm-3 respectively, while for the upper-channel layer, the values are 0.17 µm and 2.0×1017 cm-3 respectively. The simulated results showed that the middle-recessed MSFETs structure with dual-channel layer have a saturation drain current density of 445 mA/mm, source– drain breakdown voltage of 175 V and maximum output power density of 9.1 W/mm. These results are improved compared to side-recessed structure with single channel MESFETs simulated in this work with a channel thickness of 0.25 µm and doping concentration of 2.4×1017 cm-3 . Therefore, the middle-recessed structure 4H-SiC MESFET with dual-channel layer has superior DC performances compared to the similar device based on the side-recessed structure with single channel.

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