Performance Improvement of Partially Silicon-on-Insulator Lateral Double-Diffused Metal–Oxide–Semiconductor Field-Effect Transistors Using Doping-Engineered Drift Region

In this paper, we investigate the characteristics of a drift region engineered lateral double-diffused metal–oxide–semiconductor field-effect transistor (LDMOSFET) based on partially silicon on insulator (PSOI) technology. The structure, which is called DEPSOI (drift region engineered PSOI), has a drift region with two different doping density levels. The structure only needs one additional fabrication mask, compared to the conventional power PSOI device. In the drift region, a new peak is formed in the lateral electric field distribution at the boundary between the drift areas, which leads to a flatter electric field profile and subsequently a higher breakdown voltage (BV) compared to those of a conventional device. The results show that the DEPSOI LDMOSFET has a BV which is about 64% more than that of an optimized conventional PSOI LDMOSFET with the same dimension. The use of two different doping density levels allows simultaneous optimization of different device parameters. Having one part of drift region with a higher doping density level leads to an improvement of the on-state resistance (R_on). Finally, DEPSOI LDMOSFET has a superior heat dissipation property than that of the conventional LDMOSFET structures. The effects of varying different physical parameters of the structure on the characteristics of the transistor are also studied.