Endpoint detection method and apparatus

摘要

Disclosed are metal fuse structures and methods for making the same. The method includes forming the fuse structure from a metallization layer. Depositing a bottom oxide layer, that is an HDP oxide, over the fuse structure that is formed from the metallization layer. Depositing a doped oxide layer over the base oxide layer. Depositing a top oxide layer over the doped oxide layer. Etching through the top oxide layer. Detecting an increased level of a dopant species that is emitted when the doped oxide layer begins to etch. The method further includes terminating the etching when the increased level of dopant species is detected. Wherein at least the bottom oxide layer remains over the fuse structure that is formed from the metallization layer.