Patent ID: 6583055
Filing Date: 2003-06-24
Classification: H01L

Abstract:
A method of forming a stepped contact trench for a semiconductor device, comprising the steps of:forming a cap layer on a semiconductor substrate; sequentially forming a first dielectric layer and a second dielectric layer on the cap layer; etching a preliminary contact hole through the second dielectric layer and the first dielectric layer; implanting dopants in the substrate through the preliminary contact hole and then annealing to diffuse the dopants to form a doped region; etching to remove the cap layer exposed by the preliminary contact hole; etching the substrate underneath the preliminary contact hole to form a trench with the doped region provided at the upper edges of the trench; isotropically etching the sidewalls of the preliminary contact hole with an etching agent having a higher etch rate for the second dielectric layer than for the first dielectric layer, thereby forming a contact hole with a stepped sidewall; and etching to remove the cap layer exposed by the stepped contact hole.