Low on-resistance trench lateral MISFET with better switching characteristics and method for manufacturing same

摘要

A high-voltage and low on-resistance semiconductor device incorporates a trench structure that provides improved switching characteristics. In a preferred embodiment, a Trench Lateral Power MISFET is provided having a gate, channel and drift regions that are built on the side-walls of the trench. The process used to form the MISFET involves a self-aligned trench bottom contact hole to contact a source provided at the bottom of the trench to achieve minimum pitch and very low on-resistance. An example of a MISFET with 80 V breakdown voltage having a cell pitch of 3.4 microns is disclosed in which an on-resistance of 0.7 m&OHgr;-cm² is realized. The switching characteristics of the MISFET are twice as good as that of prior MISFET device structures.