A novel SON LDMOS with Triple-RESURF technology

• A novel high voltage Triple-RESRUF Silicon-On-Nothing (SON) LDMOS is proposed.
• The breakdown mechanism of the proposed device is analyzed.
• The proposed device is compared with conventional device on breakdown voltage and electric field by simulation.
• The thermal characteristic is worse and breakdown voltage is higher when the air layer is thicker and longer.
• An analytical model of Triple-RESURF SON LDMOS is presented and shows a fair agreement with the numerical results.

A novel high voltage Triple-RESURF Silicon-On-Nothing (SON) LDMOS is proposed for the first time in this paper. The LDMOS is characterized by an air layer instead of buried oxide layer in SOI (Silicon-On-Insulator) LDMOS and Triple-RESURF structure reduces the specific resistance (Ron,sp). Owing to the low permittivity of air, the vertical electric field in the dielectric layer is enhanced, contributing to the improvement of breakdown voltage (BV). The numerical results show that BV of Triple-RESURF SON LDMOS increases by 96% comparing with Triple-RESURF SOI LDMOS, due to the increase of vertical electric field by 125%. An analytical model of Triple-RESURF SON LDMOS is presented and shows a fair agreement with the numerical results.