Drain current thermal noise modeling for deep submicron n- and p-channel MOSFETs

Abstract

The drain current thermal noise has been measured and modeled for the short-channel devices fabricated with a standard 0.18 mum CMOS technology. We have derived a physics-based drain current thermal noise model for short-channel MOSFETs, which takes into account the velocity saturation effect and the carrier heating effect in gradual channel region. As a result, it is found that the well-known Q(inv)/L-2-formula, previously derived for long-channel, remains valid for even short-channel. The model excellently explained the carefully measured drain thermal noise for the entire V-GS and V-DS bias regions, not only in the n-channel, but also in the p-channel MOSFETs. Large excess noise, which was reported earlier in some other groups, was not observed in both the n-channel and the p-channel devices. (C) 2004 Elsevier Ltd. All rights reserved.