Trench-gated device having trench walls formed by selective epitaxial growth and process for forming the device

摘要

A trench-gated power device (100) comprises a substrate (101) having an overlying epitaxial layer disposed on an upper layer of the substrate, well regions containing source (110) and body regions (111), a trench gate, and a drain region (113). The gate trench (105) having sidewalls (106) that comprise selectively grown epitaxial material. A dielectric layer (102) having an upper surface and thickness and width dimensions that substantially correspond to the height and width dimensions of a gate trench is formed on an upper layer of the substrate. A layer (103) of epitaxial material is grown on the upper layer of the substrate and the dielectric layer (102) and planarized to be substantially coplanar with the upper surface of the dielectric layer (102), which is than removed, so as to form gate trench sidewalls (106) that comprise selectively grown epitaxial material. The process comprising lining the trench (105) with a dielectric material (107) and filling the lined trench with a conductive material (108). <IMAGE>