Patent ID: 7622395

Claim:
A two-step method for etching a fuse window on a semiconductor substrate, comprising: providing a semiconductor substrate having thereon a fuse interconnect-wire embedded in a dielectric film stack, wherein said dielectric film stack comprises a target dielectric layer overlying said fuse interconnect-wire, at least one intermediate dielectric material layer overlying said target dielectric layer, and a passivation layer overlying said intermediate dielectric material layer, a photoresist layer disposed over said passivation layer, wherein said photoresist layer has an opening that is directly above said fuse interconnect-wire and defines said fuse window; performing a first dry etching process to non-selectively etch said passivation layer and said intermediate dielectric material layer through said opening thereby exposing said target dielectric layer; performing a first thickness-measurement step to measure thickness of said target dielectric layer after said first dry etching process; performing a second dry etching process, based on said measured thickness of said target dielectric layer in said first thickness-measurement step, to etch away a portion of said exposed target dielectric layer, thereby forming said fuse window; and performing a second thickness-measurement step to measure a remaining thickness of said target dielectric layer after said second dry etching process.