Thin-film LDMOS on partial SOI with improved breakdown voltage and suppressed kink effect

Abstract

Thin-film (TF) lateral double-diffused metal-oxide-semiconductor field effect transistor (LDMOSFET or LDMOS) of small dimensions on partial silicon-on-insulator (PSOI) with improved breakdown voltage and suppressed kink effect is introduced and studied. The silicon window and field plate can modulate the surface electric field of silicon film and, thus, their design parameters can be adjusted to achieve optimal breakdown voltage. Moreover, the silicon window can also provide a conduction path from the thin silicon film to the substrate and prevent hole accumulation in the floating body of silicon-on-insulator (SOI) devices, which can consequently suppress the kink effect. Effects of the device parameters (e.g. location of the field plate, location of silicon window, and doping concentrations of the drift region, silicon window and substrate) that control the performance of TF PSOI LDMOS are carefully studied. Compared with the conventional TF SOI LDMOS of small dimensions, the simulation results show that this proposed TF PSOI LDMOS exhibits approximately 100% improvement on the breakdown voltage and entirely eliminates the kink effect.