New Super-Junction LDMOS Based on Poly-Si Thin-Film Transistors

Abstract

A multi-channel super-junction lateral doubled-diffused MOSFET (SJ-LDMOS) that is developed from thin film transistor technology is proposed. To optimize the breakdown voltage ( ${\mathrm{ V}}_{\mathrm{ BD}} $ ) and to reduce the specific on-resistance ( $\text{R}_{\mathrm{ SP}}$ ), a new structure called REC-SJ LDMOS, with two symmetrical rectangular p-pillars, was designed and simulated. The REC-SJ LDMOS presents not only a higher ${\mathrm{ V}}_{\mathrm{ BD}} $ than the conventional super-junction (Conv-SJ) LDMOS due to the more uniform electric field distribution in the drift region, but also a better power figure of merit on account of the much lower $\text{R}_{\mathrm{ SP}}$ than Conv-SJ. Accordingly, the new poly-Si REC-SJ LDMOS provides a way to break through the tradeoff between the ${\mathrm{ V}}_{\mathrm{ BD}} $ and the $\text{R}_{\mathrm{ SP}}$ .