Field tailored SiC MESFET design and modeling

FET linearity is dictated by electric field distribution along the channel. Field profile shaping is known to improve device linearity. We study the effect of field tailoring in 5μm long 4H SiC with two 0.5μm long gates. The gates were biased in a manner that Vg1>Vg2. We demonstrate that proper ratio of voltages Vg1 /Vg2 reduce the strength of electric field along the channel, thus making transconductance more uniform. In field tailored MESFET the gm is about 21mS/mm with sharp pinch-off and good saturation characteristics in comparison to conventional single gate device. Shaping of electrical field increased the breakdown by 100%, with minimal effect on high frequency performance.