High-Density Laser Linking of Metal Interconnect

摘要

Laser programmed interlevel metal connections have been developed as a means toachieve high density linking for customization in programmable gate arrays and for additive redundancy in restructurable integrated circuits. This work reports on the linking of 4 micrometer x 4 micrometer crossings of standard two level metal interconnect lines and subsequent microstructural analyses aimed at understanding the mechanism of link formation. The links were formed by focusing a laser on metal 1 through an annular region of metal 2. The mechanism of link formation appears to be a physical connection made by a fracture of the dielectric layer due to the stress of thermal expansion of the metallization with molten metal 2 filling the crack.