High performance Ge pMOSFETs with simultaneous mobility-412 cm2/V-s, EOT −0.5 nm, Ion/Ioff∼105, gate leakage∼10−4 A/cm2 by modulating interfacial layer using oxygen deficient HfOx

Abstract

A high peak hole mobility of 412 cm²/V-sec at Ninv=1.8×10¹² cm⁻², a very low Jg of ∼10⁻⁴ A/cm² at Vg=Vfb+1 V and an ultralow EOT of 0.53 nm in Ge pMOSFETs are simultaneously achieved by high-k/0D-HKVGe02 gate stack with suitable treatments. The content of Ge⁺¹ and Ge⁺² in GeOx layer are re-oxidized to higher oxidation state by gettered oxygen, which is captured by OD-HfOx from GeOx. The proposed gate stack is promising for Ge MOSFET.