High-voltage lateral trench gate SOI-LDMOSFETs

We present a lateral trench gate SOI-LDMOSFET that uses narrow trenches as channels. The lateral trench gate, which allows the channel current to flow laterally on the trench side walls, decreases its on-resistance because it increases the current spreading area of the device. The specific on-resistance ðRspÞ strongly depends on the trench depth, which affects the channel area on the side wall of the trench and the space between the trenches affects the channel density of the device. The Rsp of the suggested devices as a function of the lateral trench depth and the space between the trenches are studied. Three-dimensional numerical simulations with MINIMOS-NT have been performed to investigate the influence of device parameters on the Rsp and the breakdown voltage. The improvement in the current handling capability of the suggested device is about 8.3% compared to the conventional SOI-LDMOSFET. q 2003 Elsevier Ltd. All rights reserved.