Impact of the device scaling on the low-frequency noise in n-MOSFETs

The impact of device scaling on modern MOS technology is discussed in terms of the random telegraph signals (RTSs) and low-frequency noise in n-MOSFETs with gradually decreased channel widths. RTSs with very large amplitude (>60%) are observed in the devices with ultra-narrow channels at room temperature for the first time. Furthermore, low-frequency noise spectra having both 1/f′ and Lorentzian type are found separately in the same ultra-narrow channel at different gate bias voltage, whereas only 1/f′ noise is observed in relatively wide channels. The observations strongly suggest that low-frequency noise in weak inversion dominantly suffer from carrier mobility fluctuation rather than carrier number fluctuation in ultra-narrow channels, which is confirmed by numerical simulations.