A Novel 1200-V LDMOSFET With Floating Buried Layer in Substrate

A novel 2-mum thin-drift-layer power MOSFET with an n-type floating buried layer (FBL) in substrate is proposed in this letter. Since the charges in the buried layer modulate the bulk electric field, a nearly uniform electric field is obtained, and the vertical breakdown voltage (BV) is significantly improved. Simulation results show that the BV of the proposed FBL lateral double-diffused MOSFET (LDMOSFET) is increased from 743 V of the conventional LDMOSFET to 1332 V with the same 100 mum drift region length. Furthermore, the figure-of-merit of the FBL-LDMOSFET is better than that of the conventional LDMOSFET.