Interconnect structure having a multi-deck conductive feature and method of forming the same

Abstract

The present disclosure provides a semiconductor device structure that includes: a fin active region extruded above a semiconductor substrate; a gate stack disposed on the fin active region, wherein the gate stack includes a gate dielectric layer and a gate electrode; source/drain (S/D) features formed on the fin active region and interposed by the gate stack; and a conductive feature electrically connected to one of the gate electrode and the S/D features. The conductive feature includes a bottom metal feature of a first metal; a top metal feature of a second metal over the bottom metal feature, wherein the second metal is different from the first metal in composition; a barrier layer surrounding both the top metal feature and the bottom metal feature; and a liner surrounding both the top metal feature and separating the top metal feature from the bottom metal feature and the barrier layer.