EUV degradation of high performance Ge MOSFETs

High energy 13.5 nm EUV (~92 eV) induced Ge MOSFET degradation is reportedly for the first time. The degradation of threshold voltage, subthreshold swing, and channel mobility is attributed to the generation of interface traps and oxide fixed charges. Much more severe degradation of S.S. on nFETs as compared to pFETs suggests that acceptor type D_it in the upper half of Ge bandgap are generated by EUV radiation. ΔQ_it may originate from the dangling bonds at interface. Positive ΔQ_f is due to the fixed charges of oxygen vacancy. The generation of bulk defects in Ge increases the drain leakage current, leading to the reduction of current on/off ratio.