High mobility high on/off ratio C-V dispersion-free Ge n-MOSFETs and their strain response

The record high peak mobility of ~1050 cm²/V-s on (001) Ge substrate is demonstrated in NFET. High-quality Ge/GeO₂ interface is ensured by rapid thermal oxidation (RTO) and remote ozone plasma treatment. The best achieved subthreshold swing is 150mV/dec and the on/off ratio is 2×10⁴. The low defective n⁺/p junction produced a record high on/off ratio of 2×10⁵, an ideality factor of 1.05 and strong electroluminescence. For the first time, it is reported that the uniaxial <;110>; tensile strain (0.08%) on <;110>; channel direction gives the best mobility enhancement (12%) among the different strain configurations, consistent with theoretical calculation.