Backend process for fuse link opening

摘要

The present invention is directed to a method of forming an insulative layer over a fuse link in a semiconductor device that is sufficiently thick to encapsulate the fuse link during laser opening, thereby preventing vaporized metal from re-depositing on the fuse link. The layer is also sufficiently thin to allow the laser to penetrate the insulative layer during laser opening of the fuse. A primary dielectric layer is formed over a metal fuse link, the primary dielectric having a predetermined deposition thickness over the fuse link. The primary dielectric layer is then covered with an etch interrupting layer. The etch interrupting layer is covered with a secondary dielectric layer and a portion of the secondary dielectric layer is then removed, resulting in an interlayer dielectric (ILD) stack formed from the etch interrupting layer and the remaining secondary dielectric layer. The ILD has a selected thickness that is greater than the thickness of the primary dielectric layer. A metal layer is formed over the interlayer dielectric and then the layers over the etch interrupting layer and above the metal fuse link are then removed. Finally, the etch interrupting layer is removed from above the primary dielectric layer so as to expose a portion of the primary dielectric layer disposed above the metal fuse link.