Performance enhancement in Ge pMOSFETs with <1 0 0> orientation fabricated with a Si-compatible process flow

The electrical characterization of Ge pMOSFETs having <1 1 0> and <1 0 0> orientations with gate lengths of 3 μm have been demonstrated with a Si-compatible process flow. Employment of <1 0 0> orientation in Ge pMOSFETs without incorporation of strain provided ∼10% enhancement in effective hole mobility and drive current when compared to <1 1 0> oriented regular transistors. In this fabrication technology, the effective hole mobility improves from 190 cm²/V s for <1 1 0> devices to 210 cm²/V s for the <1 0 0> oriented Ge devices at room temperature, which is ∼2 times the hole mobility of Si pFET devices. This study also presents first time investigation of post metallization anneal (PMA) at 350 °C in H₂ ambient for <1 0 0> Ge pMOSFETs. The overall performance of the devices has been enhanced by 15% after performing PMA. It is likely attributed to a strong decrease of D_it, improving the transistor performance. These results indicate that the <1 0 0> Ge pMOSFETs could be a viable candidate for future low voltage high speed CMOS applications.