A trench lateral power MOSFET using self-aligned trench bottom contact holes

A novel Trench Lateral Power MOSFET (T-LPM) structure and its fabrication process are presented in this paper. The gate, channel, and the drift region are built on the side-wall of the trench. The process uses self-aligned trench bottom contact holes to the drain to achieve minimum pitch and very low on-resistance. A T-LPM, with 80 V breakdown voltage, has a cell pitch of 4 /spl mu/m which is about half that of the Conventional Lateral Power MOSFETs (C-LPM). The specific on-resistances for the T-LPM and C-LPM are 0.8 m/spl Omega/-cm/sup 2/ and 1.6 m/spl Omega/-cm/sup 2/ respectively for a 80 V breakdown.