Session 4B-4

Physical Origins of Mobility Enhancement
of Ge pMISFETs with Si Passivation Layers

 

Abstract

We have been systematically investigated the mobilities of the Ge pMISFETs with Si passivation layers in order to clear the origins of the mobility enhancement. As a result, for the first time, the physical origins were comprehensively cleared. It is found that reduction of Coulomb scattering due to the separation of mobile carriers from interface charges across the Si layer and the formation at Si/Ge interface of high mobility channels due to the suppression of roughness scattering largely contribute to the mobility enhancement. Also, it is found that the dislocation and the strain-undulation introduced in the Si layer cause the mobility degradation.