Multilayer electrical interconnect fabrication with few process steps

摘要

Method for making a multilayer electrical interconnect with stacked pillars between layers using a minimal number of conventional process steps. The method includes sputtering a chromium/copper/titanium trilayer on a dielectric base, depositing a patterned mask on the trilayer, etching the exposed trilayer, removing the mask, depositing a layer of polyimide over the unetched copper, forming a via in the polyimide above the copper, electrolessly plating nickel into the via, and polishing the interconnect to form a planar top surface.