Significant Performance Enhancement of UTB GeOI pMOSFETs by Advanced Channel Formation Technologies

Advanced channel formation technologies, such as precise control of GeOI body thickness (Tbody), surface roughness and interfacial quality, utilizing Si-passivation/Ge-channel/SiGe hetero-epitaxy and Ge digital etching (DE) techniques were implemented for UTB GeOI structure. Si passivation for Ge/BOX interface has been verified to suppress Coulomb scattering owing to better interfacial quality. Insertion of SiGe etching stop (ES) layer and dozens DE (DDE) were found to be quite effective to reduce Tbody fluctuation as well as surface roughness, resulting in the significant improvement of mobility. As a result, we have demonstrated record high hole mobility of ~200 cm2/Vs in UTB GeOI pMOSFETs without the strain technology, which outperforms Si universal mobility by 2 times even under Tbody of 9 nm.