Device characteristics of short-channel and narrow-width MOSFET's

MOS devices have become smaller and smaller as the integrated circuit technology advances. A thorough understanding of the device characteristics of these small-size devices is important. In this paper, three small-geometry effects; namely, short-channel effect (SCE), narrow-width effect (NWE), and minimum-size effect (MSE) (which combines SCE and NWE together) are discussed. The variations of threshold voltage, mobility, and drain current are illustrated for minimum-size devices. The threshold voltage decreases as channel length decreases but increases as device width decreases. Carrier mobility also decreases as the device size becomes small. Simple device models of minimum-size devices are proposed for threshold voltage and carrier mobility. Experimental results of threshold voltage, mobility, and drain current are compared with the calculated results.