Fabrication of five-layered interconnection CMOS LSI using polyimide resist insulators

A five-metal-layered interconnection 20k gate CMOS LSI is fabricated using polyimide resist insulators. It is proved that the use of polyimide resist insulators results in excellent planarization, small residual stress, a smooth via profile, and a reduction in the number of steps required for the process. As a result, this technique appears to be a practical means of fabricating five or more layered interconnection systems.