Patent ID: 6323123
Filing Date: 2001-11-27
Classification: H01L

Abstract:
A method for forming a low-K dual damascene structure, comprising:providing a substrate;forming a barrier layer over said substrate;forming a first dielectric layer over said barrier layer;forming an etching stop layer over said first dielectric layer;forming a second dielectric layer over said etching stop layer;forming a hard mask over said second dielectric layer;forming a first photoresist layer having a first pattern on said hard mask;dry etching by using said first photoresist layer as a mask, and punching through in turn said hard mask, said second dielectric layer, said etching stop layer and said first dielectric layer to form a via hole;removing said first photoresist layer and said hard mask;filling a gap-filling material on said second dielectric and into said via hole;etching back said gap-filling material to expose surface of said second dielectric and said gap-filling material;forming an anti-reflection layer over said second dielectric and said gap-filling material;forming a second photoresist layer having a second pattern on said anti-reflection layer;dry etching said anti-reflection layer by using said second photoresist layer as a mask until stopping on said etching stop layer, thereby forming a trench having larger horizontal size than said via hole;removing said gap-filling material; andremoving said second photoresist layer to form an opening of a damascene.