High-pressure hydrogen annealing improving the cryogenic operation of Si (110)-oriented n-MOSFETs

Abstract

This study experimentally investigated the effects of an additional high-pressure hydrogen annealing (HPHA) on the cryogenic operation of Si (110)-oriented n- MOSFETs. The HPHA induced improvements in the subthreshold swing (SS), threshold voltage (Vth), and ON current at cryogenic temperatures. Further, we analyzed the SS-drain current curves using the analytical model and concluded that HPHA reduced the density of the band-edge states. In addition, the analysis of the temperature-dependent Vth supported this conclusion. Furthermore, effective mobility analysis results indicated that the improvement in the ON current was attributable to the improvement in the band-edge states. Therefore, we conclude that the HPHA process positively affected the Si/SiO2 interface and reduced the interface-related band-edge states, thereby improving the cryogenic operation of MOSFETs.