Process and Structure for Laser Fuse Blowing
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-27
By placing an etch stop layer over fuse sites soon after fuses are defined, fuse blowing is performed through a well controlled, thin insulating layer, after most of overlying insulating material is removed. Referring to the figure, by standard processing fuses 2 are deposited and defined over insulating layer 4 and covered by reflowable glass layer 6. During usual definition of refractory metal M1 for first level circuitry, a region over the fuses is left covered by M1 by altering the M1 mask. This M1 region subsequently is used as an etch stop. Normal processing is then used to deposit oxide layer 8. Next, second level circuitry M2 is deposited and defined by standard processing. When M2 is an Al-based material, no further etch stop material is required over M2 for this process.