Abstract
Advanced HEtero-Layer-Lift-Off (HELLO) technology utilizing Ge/SiGe/Ge hetero-epitaxy technique was implemented to realize high quality ultrathin body (UTB) Ge-on-insulator (GeOI) structures. Top interfacial quality of GeOI has been taken care by plasma enhanced ALD-Al2O3 passivation. On the other hand, bottom interfacial quality of GeOI was improved by N2O plasma treatment or Si passivation for UTB GeOI n and pMOSFETs, respectively. Besides, GeOI body thickness (Tbody) was precisely controlled through SiGe etch stop layer and digital etching process. For lowering parasitic resistance of S/D regions of bulk Ge n and pMOSFETs, ion implantation after germanidation (IAG) has been demonstrated as an effective way. Moreover, high performance UTB GeOI n and pMOSFETs with Tbody less than 5 nm have been successfully fabricated for the first time. Thickness dependence of carrier mobility of GeOI has also been investigated systematically through split-CV method, revealing a great potential of UTB GeOI structures in future Ge CMOS application.