Patent ID: 6750116
Filing Date: 2004-06-15
Classification: H01L

Abstract:
A method for making an asymmetric interior structure in a trench or contact hole of a substrate layer, comprising the steps of:forming at least one trench or contact hole in a substrate layer, the trench or contact opening comprising a first sidewall, second sidewall, and a bottom; forming a first dielectric layer on the first sidewall, the second sidewall, and the bottom; performing a tilt angle ion implantation process to dope ions into the first dielectric layer on the first sidewall and on the bottom, but not dope ions into the first dielectric layer on the second sidewall, thereby resulting in etching selectivity between the doped first dielectric layer on the first sidewall and on the bottom, and the non-doped first dielectric layer on the second sidewall; and selectively etching away the doped first dielectric layer on the first sidewall and on the bottom, thereby forming an asymmetric interior structure in the trench or contact hole.