Investigation of degradation mechanism after negative bias temperature stress in Si/SiGe channel metal-oxide-semiconductor capacitors induced by hydrogen diffusion

In this research, based on I-V and C-V measurement at different temperatures, the interface defect density in the device with the Si/SiGe channel was discussed. In addition, negative bias temperature instability (NBTI) is also studied. In previous research, most of the flat-band voltage (VFB) shifts during NBTI stress was attributed to hole injection. In this article, however, the release of atomic hydrogen from the Si–H bonds at the SiOV2/Si interface and at the SiGe interface produces a fixed oxide charge, which causes VFB shifts which vary with material.