Multi-layer metal contacts

摘要

A method for forming metal contacts within a semiconductor device includes forming a first-layer contact into a first dielectric layer that surrounds at least one gate electrode, the first-layer contact extending to a doped region of an underlying substrate. The method further includes forming a second dielectric layer over the first dielectric layer and forming a second-layer contact extending through the second dielectric layer to the first-layer contact.

主权项

1. A method for forming metal contacts within a semiconductor device, the method comprising:
forming a hard mask layer directly on opposing sidewalls and a top surface of a gate electrode over a semiconductor substrate, wherein the top surface extends between the opposing sidewalls and the hard mask layer physically contacts the opposing sidewalls and the top surface of the gate electrode; forming a first dielectric layer over the semiconductor substrate such that the first dielectric layer surrounds the gate electrode; forming a temporary dielectric layer over the hard mask layer and the first dielectric layer; forming a trench that extends through the temporary dielectric layer, first dielectric layer, and the hard mask layer, wherein the hard mask layer defines a sidewall of the trench while physically contacting the opposing sidewalls of the gate electrode; forming a first-layer contact in the trench, the first-layer contact extending to a doped source/drain region in the semiconductor substrate; after forming the first-layer contact in the trench, removing the temporary dielectric layer to expose a portion of the hard mask layer, the portion of the hard mask layer covering a top surface of the gate electrode, the top surface of the gate electrode facing away from the semiconductor substrate; forming a second dielectric layer over the first dielectric layer and the portion of the hard mask layer covering the top surface of the gate electrode; and forming a second-layer contact extending through the second dielectric layer to the first-layer contact.