High-mobility high-Ge-content Si_1-xGe_x-OI PMOS FinFETs with fins formed using 3D germanium condensation with Ge fraction up to x∼ 0.7, scaled EOT∼8.5Å and ∼10nm fin width

Abstract

We demonstrate scaled High-Ge-Content (HGC) SiGe-OI finFET with Ge up to 71%, using a CMOS-compatible approach. For the first time, aggressively scaled HGC relatively-tall fins with vertical sidewalls and sub-10nm widths have been demonstrated using an enhanced 3D-Ge-condensation technique. An improved Si-cap-free HK/MG process featuring optimized IL has been developed resulting in scaled EOT and impressive long channel SS=69mV/dec. The gate stack results in realization of enhancement-mode devices for Ge content ∼0.6. Moreover, long-channel mobility characteristics at scaled EOT as well as short-channel pMOS FinFETs with decent cut-off behavior and performance are demonstrated, for the first time. As a result, we report the highest HGC SiGe pMOS FinFET mobility of ∼300cm2/Vs at Ninv=1013cm-2 at scaled EOT=0.85nm.