Recess gate transistor

Abstract

A method of forming a semiconductor device is provided, comprising forming a plurality of hard masks on a substrate by patterning an insulating layer; forming a plurality of trenches in the substrate, each trench having trench walls disposed between two adjacent masks and extending vertically from a bottom portion to an upper portion; forming an insulating layer on the hard masks and the trench walls; forming a conductive layer on the insulating layer; etching the conductive layer to form conductive layer patterns to fill the bottom portions of the trenches; depositing a buffer layer on the conductive layer patterns and the trench walls; and filling the upper portions of the trenches with a capping layer.