Effects of small gate length, gate width and s/d overhang on mosfets isolated by STI technology
See, Kwang Seng
Date of Issue2009
School of Electrical and Electronic Engineering
The focus of this dissertation is the investigation of MOS transistors with very small dimensions in terms of very short gate length (Lg), very narrow gate width (Wg) as well as very small source-drain diffusion length (Lov). The candidate observed a relatively new phenomenon of narrow width effect, which was called the anomalous narrow width effect (ANWE). For example, the threshold voltage (VT) increased with the decrease of Wg for big Wg (~ 0.6 to 1.2 µm) but VT decreased with the decrease of Wg for small Wg (< 0.6 µm); this was only observed in "very short" (e.g. 0.13 µm) NMOS transistors having a phosphorus deep source-drain implant in addition to the usual arsenic implant. ANWE is a relatively weak effect for NMOS transistors but it is a strong effect in PMOS transistors with very short Lg.
DRNTU::Engineering::Electrical and electronic engineering::Semiconductors
Nanyang Technological University