Interfacial barrier for work function modification of high performance cmos devices

Abstract

A semiconductor structure may include a semiconductor bulk region with a gate stack on the semiconductor bulk region. The source region and the drain region in the semiconductor bulk region may be located on opposing sides of a channel region below the gate stack. An interfacial layer coupled to the channel region may modify a workfunction of a metal-semiconductor contact. In a MOSFET, the metal-semiconductor contact may be between a metal contact and the source region and the drain region. In a Schottky barrier-MOSFET, the metal-semiconductor contact may be between a silicide region in the source region and/or the drain region and the channel region. The interfacial layer may use a dielectric-dipole mitigated scheme and may include a conducting layer and a dielectric layer. The dielectric layer may include lanthanum oxide or aluminum oxide used to tune the workfunction of the metal-semiconductor contact.