Metal fuse in copper dual damascene
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorChao-Chieh Tsai
Life of this patent
Estimating the term…
Abstract
A fuse structure and process for forming it are described. The fuse is formed from a compound layer of aluminum and chromium. These two layers are shaped to form a stripe that bridges a gap between two copper dual damascene connectors. By controlling the degree of overlap between the stripe and the connectors the conductance of heat from the stripe into the connectors can be varied, thereby allowing control of the manner in which the fuse blows when irradiated. Since there is no copper in the fuse material, blowing a fuse does not introduce unprotected copper sources into the structure.
Claims11
A process for forming a fuse structure, comprising:
- providing a partially completed integrated circuit having a first dielectric upper surface in which are embedded, and exposed, first and second dual damascene connectors, each having a width and each having an inner edge and an outer edge, said inner edges being separated by a gap having a length;
- depositing a layer of chromium on said upper surface, including the exposed dual damascene connectors;
- depositing a layer of aluminum over the layer of chromium;
- patterning and etching the aluminum and chromium layers to form a fusible stripe, having said width, that extends no further than said outer edges and that overlaps the first inner edge by a first amount and the second inner edge by a second amount that may be different from the first amount, thereby controlling conductance of heat between the stripe and said first and second dual damascene connectors;
- and
- depositing a second dielectric layer over the first dielectric surface, including said stripe.
Dependencies are inferred from the claim text.