International Business Machines Corporation
Forming replacement low-k spacer in tight pitch fin field effect transistors

Abstract:

A semiconductor device that a fin structure, and a gate structure present on a channel region of the fin structure. A composite spacer is present on a sidewall of the gate structure including an upper portion having a first dielectric constant, a lower portion having a second dielectric constant that is less than the first dielectric constant, and an etch barrier layer between sidewalls of the first and second portion of the composite spacer and the gate structure. The etch barrier layer may include an alloy including at least one of silicon, boron and carbon.