Stacked multi-gate device with low contact via resistance and methods for forming the same

Abstract

A semiconductor device that has two transistors and a source/drain contact. The first transistor has a layer of semiconductor material that acts as a channel, a structure that serves as a gate and wraps around the semiconductor channel layer, and two epitaxy structures on either end of the semiconductor channel layer that function as the source and drain. The second transistor is situated above the first transistor and has similar components, including a semiconductor channel layer, gate structure, and source/drain epitaxy structures. The connection between the first and second source/drain epitaxy structures is made by a source/drain contact that passes through one of the second source/drain epitaxy structures. This contact is made up of a metal plug and a metal liner that lines the plug.