Investigation of Coulomb Mobility in Nanoscale Strained PMOSFETs

This paper provides an experimental assessment of Coulomb scattering mobility for advanced strained devices. By accurate short-channel mobility extraction, we examine the impact of process-induced uniaxial strain on Coulomb mobility in short-channel pMOSFETs. Our extracted Coulomb mobility shows very weak stress dependency at room temperature. This finding has also been verified in both long- and short-channel devices by the four-point wafer bending measurement. Therefore, in order to maximize the process-induced strain efficiency on nanoscale pMOSFETs, lower surface impurity concentration is suggested to avoid the Coulomb mobility domination in carrier transport.