Abstract
Single crystalline GeSn grown on Ge substrate by solid phase epitaxy was developed and employed as the platform to implement Al 2 O 3 -gated N-MOSFETs. O 2 plasma treatment was confirmed to be an effective avenue for surface passivation by forming GeSnOx. The passivation makes a Dit as low as 1.62×1011 cm-2eV-1 and high peak mobility of 518 cm2/(Vs). To mitigate FL pinning on n-GeSn for low contact resistivity, O 2 plasma treatment and formation of Yb stanogermanide on GeSn were respectively employed to suppress surface states. The significant FL depinning is evidenced by the ?BN of 0.12∼0.13 eV with ρc less than 4.0×10-7 Ω-cm 2 . The promising processes gain an outlook on empowering high-performance GeSn devices.