Dual damascene gap filling process

摘要

A method of forming a metallization layer in a semiconductor substrate includes forming a patterned dielectric layer on a substrate, the patterned dielectric layer having a plurality of first openings. A first conductive layer is formed in the plurality of first openings. A patterned mask layer is formed over portions of the first conductive layer outside the plurality of first openings, the patterned mask layer having a plurality of second openings, wherein at least a subset of the second openings are disposed over the first openings. A second conductive layer is filled in the plurality of second openings. The patterned mask layer is removed to leave behind the conductive layer structures on the substrate. The substrate is heated to form a self-forming barrier layer on the top and sidewalls of the conductive layer structures.

主权项

1. A method of fabricating a semiconductor device, comprising:
forming an etching stop layer over a substrate; forming a patterned dielectric layer over the etching stop layer, the etching stop layer disposed between the patterned dielectric layer and the substrate, the patterned dielectric layer having a plurality of first openings; forming a first conductive layer in the plurality of first openings; forming a mask layer over first portions of the patterned dielectric layer disposed outside the plurality of first openings, the mask layer having a plurality of second openings, wherein at least a subset of the second openings are disposed over the first openings; filling a second conductive layer in the plurality of second openings, the second conductive layer defining conductive layer structures shaped by the second openings, the conductive layer structures disposed laterally adjacent to the mask layer; removing the mask layer laterally adjacent to the conductive layer structures to leave behind the first portions of the patterned dielectric layer and the conductive layer structures on the substrate; and after the removing, annealing the conductive layer structures to form a self-forming barrier layer on a top and sidewalls of the conductive layer structures.