Patent ID: 6268283
Filing Date: 2001-07-31
Classification: H01L

Abstract:
A method of forming a dual damascene structure in a low-permittivity dielectric layer, comprising:forming a first low-permittivity dielectric layer on a substrate;forming an etching stop layer on the first low-permittivity dielectric layer;forming a second low-permittivity dielectric layer on the etching stop layer;forming a hard mask layer on the second low-permittivity dielectric layer;forming a first patterned photoresist layer on the substrate;removing pairs of the hard mask layer, second low-permittivity dielectric layer, etching stop layer and first low-permittivity dielectric layer to form a opening by using the first patterned photoresist layer as a mask;removing the first patterned photoresist layer;forming, a non-conformal cap layer on the hard mask layer to cover the top region of the openingsforming a second patterned photoresist layer on the non-conformal layer;removing parts of the non-conformal cap layer, hard mask layer and second low-permittivity dielectric layer to form a trench;removing the second patterned photoresist layer;removing the non-conformal cap layer; andfilling the opening and trench with a conductive material.