Patent ID: 6069090
Filing Date: 2000-05-30
Classification: H01L

Abstract:
A method of fabricating a semiconductor device, wherein a dense region of the semiconductor device comprises a dense arrangement of a plurality of first recesses each with a lateral dimension of 1 .mu.m or less and a plurality of first projections interposed between the first recesses, and a sparse region of the semiconductor device comprises a sparse arrangement of a plurality of second recesses each with a lateral dimension of 1 .mu.m or more and a plurality of second projections interposed between the second recesses, said dense and sparse regions being formed by using an etch mask and etching a semiconductor substrate in a reaction chamber, said method comprising:a first step of forming the etch mask on the semiconductor substrate, said etch mask having a dense region with a dense arrangement of a plurality of first mask portions each having a lateral dimension and a plurality of first opening portions interposed between the first mask portions, and having a sparse region with a sparse arrangement of a plurality of second mask portions each with a lateral dimension different than the lateral dimension of each of the first mask portions and a plurality of second opening portions interposed between the second mask portions; anda second step of dry etching a layer of the semiconductor substrate, wherein a pressure and a flow rate of an etch gas discharged in the reaction chamber are controlled such that the lateral dimension of a lower part of each of the second recesses becomes close to a desired dimension that is larger than the lateral dimension of each of the second mask portions.