A novel substrate Voltage-assisted RESURF technique in SOI LDMOS with a heavily doped drift region

•We propose a novel substrate voltage-assisted (SVA) RESURF technique in SOI LDMOS with a heavily doped drift region.•We design an external control circuit based on SOI LDMOS. A zero bias is applied to the substrate for the on-state and a negative bias is applied to the substrate for the off-state.•We develop an analytical model to calculate the appropriate substrate voltage.•The results show that the proposed technique can improve the off-state breakdown voltage, which remains at the same level as the RESURF device. The drain leakage current and its sensitivity to the temperature are also reduced.•The results show that the proposed technique can achieve low specific on-resistance, large saturation current, high transconductance, increased cut-off frequency and improved turn-on/off characteristics compared to the RESURF device with a lightly doped drift region.