Impact of the Si Content on the Electrical Properties of NiSi x Ge1–x Source/Drain Contact Metal for Ge pMOSFETs

Abstract

The electrical properties of NiSiGe alloys with different compositions have been investigated, as a function of Si content. It is found that the resistivity of NiSiGe decreases with increasing the Si content. In addition, the NiSiGe exhibits a smaller Schottky barrier height (SBH) with p-Ge with a higher Si component, attributable to the increased work function. As a result, the high Si content NiSiGe alloy is a promising candidate for the contact metal in the Ge pMOSFETs with sufficiently suppressed source/drain (S/D) parasitic resistance. It is confirmed that the NiSiGe is feasible to satisfy the requirements as the contact metal material for Ge pMOSFETs in 5-nm node and above technology node, by modulating the Si content.