Methods for fabricating anti-fuse structures

摘要

A method for substantially reducing variations in a programming voltage of an anti-fuse structure formed on an integrated circuit wafer. The anti-fuse structure has a metal-one layer, an anti-fuse layer disposed above the metal-one layer, a oxide layer disposed above the anti-fuse layer, and a via hole in the oxide layer through to the anti-fuse layer for receiving a deposition of a metal-two material. The method includes the step of rendering a selected anti-fuse area susceptible to fuse link formation by reducing a resistivity of the selected anti-fuse area to diffusion of atoms from one of the metal-one layer and the metal-two layer when a programming voltage is applied between the metal one layer and the metal two layer. The selected anti-fuse area is located in the anti-fuse layer and substantially adjacent to and outside of an anti-fuse area directly below the via hole. The method further includes the step of depositing the metal-two material into the via hole.