Low-frequency noise in narrow channel MOSFETs

The characteristics of low-frequency (LF) noise in n-metal oxide semiconductor field effect transistors (n-MOSFET) with ultra-narrow channels have been investigated. LF noise spectra having both 1/fⁿ and Lorentzian type are found separately in the same narrow channel at different gate bias voltage, while only 1/fⁿ noise is observed in relative wide channels. Furthermore, random telegraph signals (RTSs) with very large amplitude are observed in the devices with narrow channels at room temperature. The observations strongly suggest that LF noise in weak inversion dominantly suffer from carrier mobility fluctuation rather than carrier number fluctuation in narrow channels.