A 5V/200V SOI device with a vertically linear graded drift region

摘要

The dependence of the avalanche breakdown voltage on vertically linear doping gradient of the drift region based on Silicon-On-Insulator (SOI) lateral diffuse metal oxide semiconductor (LDMOS) is studied. Vertically linear doping profile (VD) of the LDMOS structure is exhibited to obviously improve safe of operation area (SOA) from the conventional uniform and variable linear doping structure. From the BFOM (Baliga''s Figure of Merits), optimal relationship between breakdown voltage and on-state resistance (RonA) is found. The simulation results the breakdown voltage of the VD SOI LDMOS device can be improved by 19%,and 35% and the on-state resistance can be lowered by 19% and 29% at 2µm and 3µm over conventional. A 200 V LDMOS transistor with RonA of less than 800 mΩ-mm² based on various SOI layers is reported.