First Stacked Ge0.88Sn0.12 pGAAFETs with Cap, LG=4Onm, Compressive Strain of 3.3%, and High S/D Doping by CVD Epitaxy Featuring Record ION of 58μA at VOV=VDS= -0.5V, Record Gm,max of 172μS at VDS= -0.5V, and Low Noise
Journal
Technical Digest - International Electron Devices Meeting, IEDM
Journal Volume
2019-December
Date Issued
2019
Author(s)
Abstract
Record [Sn]=12% and record compressive strain of 3.3% among GeSn 3D transistors to enhance the ION are demonstrated by CVD epitaxy. For the first time, in-situ Ge0.95Sn0.05 caps are grown on stacked Ge0.ssSn0.12 channels to improve interface quality and separate carriers from the interface to achieve high mobility. LG is scaled down to 40nm to further boost the ION. Low channel doping and high S/D doping ([B]peak~1E21cm-3) can suppress the impurity scattering in the channels and reduce the contact resistivity for the S/D, respectively, to reveal the intrinsic merit of the high mobility of GeSn. The stacked 3 Ge0.88Sn0.12 nanosheets achieve record ION of 58μA at VOV=VDS= -0.5V and record Gm,max of 172μS at VDS= -0.5V among GeSn pFETs, and the performance is comparable to mature Si FinFETs, stacked Si channels, and stacked Ge channels. The caps as barriers on the Ge0.ssSn0.12 channels decrease the low frequency noise by reducing trapping/detrapping between the GeSn channels and the gate dielectrics. ? 2019 IEEE.
Subjects
Gate dielectrics; Ions; Semiconductor alloys; Silicon; Channel dopings; Compressive strain; Contact resistivities; Impurity scattering; Interface quality; Intrinsic merits; Low-Frequency Noise; Trapping/detrapping; Si-Ge alloys
Type
conference paper