Understanding Ge impact on VT and VFB in Si1−xGex/Si pMOSFETs

[Display omitted] The Ge impact on the threshold voltage (VT) and the flat band voltage (VFB) of SiGe pMOSFETs is evaluated through a comparison of experiments and simulations with various SiGe thicknesses and Ge contents. Increasing Ge content shifts linearly (VT–VFB) in full agreement with Poisson–Schrodinger simulation results accounting for adequate band discontinuity and strain. An additional VFB shift is needed to match the measured CV in accumulation, revealing a work function modification or the presence of dipole in the gate stack due to Ge diffusion.