MOS programmable memories using a metal fuse link and process for making the same

A method of forming a metal fuse link on a face of a semiconductor body in a MOS or CMOS process, comprising:

• forming a multi-level oxide over the face;
• depositing a refractory metal over said multi-level oxide with a thickness in the range of 400 to 500 Angstroms;
• patterning the metal so that it forms a length of fusing segment with a width less than 2 microns and a length of less than 3 microns joined at either end by expanded segments of the metal;
• depositing a passivation layer of insulator over the face;
• etching contacts in the passivation layer to the expanded segments;
• etching contacts to the remaining contacts in the circuit.

A fuse link in a MOS or CMOS device formed over a face of a semiconductor body, comprising:

• a layer of multi-level oxide over the face of a semiconductor body;
• a refractory metal fuse layer formed over a field oxide region of the multi-level oxide having a fuse segment with a resistance less than about 200 ohms integral with and between two spaced apart expanded regions;
• and
• an interlevel passivation layer over said fuse layer;
• an electrical contact integral with the MOS or CMOS device and extending through said passivation layer for contacting said fuse segment and carrying fusing current to said fusing segment.

A fuse link in a MOS or CMOS device formed over the face of a semiconductor body, comprising:

• a current carrying terminal connected to said MOS or CMOS device;
• a layer of multi-level oxide over the face of a semiconductor;
• a refractory metal fuse formed over a field oxide region of the multi-level oxide having a fuse segment with a resistance less that 200 ohms intergral with and between two spaced apart expanded regions;
• an interlevel passivation layer over said fuse;
• an electrical contact extending through said passivation layer and electrically connected to said current carrying terminal for carrying a fusing current from said MOS or CMOS device to said fuse segment.