High-Performance $\hbox {GeO}_{2}/\hbox {Ge}$ nMOSFETs With Source/Drain Junctions Formed by Gas-Phase Doping

We reveal that the MOVPE-based gas-phase doping can yield lower arsenic diffusion constant and lower leakage current n⁺/p junctions in Ge compared with conventional ion-implantation doping. Thus, the gas-phase doping is quite effective for realizing high-performance Ge n-channel MOSFETs. By using gas-phase doping for source/drain junction formation, the (100) GeO₂/Ge nMOSFETs have achieved high electron mobility of 1020 cm²/V·s while maintaining low junction leakage current and high I_on/I_off ratio of 10⁵. Furthermore, the (110) GeO₂/Ge nMOSFETs have also shown high electron mobility and high I_on/I_off ratio.