A Modified 1/ f Noise Model for Narrow-Width Si p-MOSFETs With Shallow Trench Isolation

In this work, a modified low-frequency (1/f) noise model is proposed for the narrow-width Si p-MOSFETs with the shallow trench isolation (STI) structure for the first time. It is found that the normalized drain current noise power spectral density (PSD) ( ${S} _{\textit {Id}}$ / ${I} _{d}^{{2}}$ ) of p-MOSFETs initially increases before sharply decreasing as the channel width ( ${W} _{g}$ ) decreases, which does not agree with the predictions of the unified 1/f noise theory ( $\boldsymbol {\Delta } {N}$ – $\Delta \mu $ model) in MOSFETs. This phenomenon indicates that the inverse-narrow-width effects (INWEs) can suppress the 1/f noise of drain current for narrow-width p-MOSFETs with STI due to the enhanced carrier density at the edge width ( ${W} _{e}$ ). Furthermore, a simple quantitative model is introduced to well predict the impact of ${W} _{e}$ on 1/f noise and estimate the channel width at which p-MOSFETs with STI exhibit the worst 1/f noise performance. And the ${W} _{e}$ for Si p-MOSFET at 55-nm node derived from this model is consistent with the reported value of $0.05~\mu $ m extracted by the parasitical series resistance ( ${R} _{{p}{0}}$ ) method, thereby effectively validating the proposed 1/f noise model. These results provide valuable insights into understanding and optimizing the 1/f noise behavior of narrow-width devices with STI in future advanced technology nodes.