Method for etching fuse windows in IC devices and devices made

摘要

A method is provided for etching fuse windows through a passivation layer and at least two inter-metal dielectric layers that are deposited on top of a fuse when the fuse is embedded in an insulating material including a top layer of silicon nitride on a semi-conducting substrate. The method can be carried out by a two-step etching process in which an opening is first etched for the fuse window through a passivation layer by a first etchant that has low selectivity to the passivation material, and then the opening is etched through the IMD layers in a second etching process by a second etchant which has high selectivity to the silicon nitride etch-stop layer. The two-step etching process can be easily controlled so that the quality and yield for the resulting fuse windows can be improved.