Patent ID: 8431486
Filing Date: 2013-04-30
Classification: H01L

Abstract:
1. A method of forming an interconnect comprising: providing a device layer on a substrate, wherein the device layer comprises at least one electrical device, an intralevel dielectric over the at least one electrical device, and a contact in electrical communication with the at least one electrical device; forming an interconnect metal layer on the device layer; forming a tantalum-containing etch mask on a portion of the interconnect metal layer that is over the contact to the at least one electrical device; and etching the interconnect metal layer with a methanol based etch chemistry, wherein the etching forms at least one trapezoid shaped interconnect from the interconnect metal layer that is in electrical communication with the contact of the at least one electrical device, the at least one trapezoid shaped interconnect having a first surface in contact with the device layer with a greater width than a second surface of the at least one trapezoid shaped interconnect that is in contact with the tantalum-containing etch mask.