Undoped Ge0.92Sn0.08 quantum well PMOSFETs on (001), (011) and (111) substrates with in situ Si2H6 passivation: High hole mobility and dependence of performance on orientation

摘要

We demonstrate high performance undoped Ge0.92Sn0.08 quantum well (QW) pMOSFETs with in situ Si2H6 passivation on (001), (011) and (111) orientations. (011) and (111)-oriented Ge0.92Sn0.08 QW pFETs achieve higher on-state current ION and effective hole mobility μeff compared to (001) devices. Ge0.92Sn0.08 (111) QW pFETs demonstrate a record high μeff of 845 cm2V−1s−1 for GeSn p-channel devices (Fig. 1). This is enabled by incorporating high biaxial compressive strain (1.43%) and eliminating dopant impurity scattering in the defect-free GeSn channel.