DC and RF characteristics improvement in SOI-MESFETs by inserting additional SiO2 layers and symmetric Si wells

Highlights: • Two wells and additional oxides are inserted and engineered in the proposed symmetric structure. • Breakdown voltage and maximum output power experience higher values. • The device current capability is much higher than conventional structure. • Cut off frequency and maximum oscillation frequency beside other RF characteristics are improved. This paper presents an efficient structure for silicon on insulator metal semiconductor FETs. In this structure, by using two symmetrical SiO₂ pieces on both sides of the channel and creating two Si wells in the buried oxide along with an extra dent, it has caused DC characteristics and frequencies to be higher than conventional structure. In the proposed device, the breakdown voltage boosts from 15.5 V in the basic structure to 19.5 V in the novel device which indicates about 25% growth. Also, the maximum output power has increased from 0.69 W/mm in the basic structure to 2.4 W/mm in the proposed one which shows an improvement more than 3 times. Also, attributable to lessening of the gate-drain and the gate-source capacitances, the frequency characteristics such as the cut-off and maximum oscillation frequencies have been improved. Therefore, the investigations demonstrate that suggested structure has proper high power and high frequency characteristics.