Low-Frequency Noise Characterization of Ultra-Low Equivalent-Oxide-Thickness Thulium Silicate Interfacial Layer nMOSFETs

摘要

Low-frequency noise measurements were performed on n-channel MOSFETs with a novel ultra-low 0.3-nm equivalent-oxide-thickness (EOT) interfacial layer (TmSiO) and two different bulk high- dielectrics (TmO and HfO). The MOSFETs were fabricated in a gate-last process and the total gate-stack EOT was 1.2 and 0.65 nm for the TmO and HfO samples, respectively. In general, both gate-stacks resulted in 1/ type of noise spectra and noise levels comparable with the conventional SiO/HfO devices with similar EOTs. The extracted average effective oxide trap density was and cmeV for TmSiO/HfO and TmSiO/TmO, respectively. Therefore, the best noise performance was observed for the gate-stack with TmO bulk high- layer and we suggest that the interface free single-layer atomic layer deposition (ALD) fabrication scheme could explain this.