EXPERIMENTAL CHARACTERIZATION AND MODELING OF ELECTRON SATURATION VELOCITY IN MOSFETS INVERSION LAYER FROM 90 TO 350 K

From saturation transconductance of devices of a 0.25-ftm CMOS technology, the saturation velocity of electrons (usat) in inversion layer from 90 to 350 K has been determined. The extracted usat at 300 K was 7.86 × 106 cm / s, which is significantly smaller than that of bulk silicon (vsat−blk), and has a much weaker temperature dependence. The ratio usat−blk / wsat is 1.27 at 300 K and is increased to 1.68 at 90 K. In addition, consistent values of t;sat have been determined for devices of three vastly different MOS technologies, which demonstrated the technology independence of usat. The results of this work are useful for developing and testing theoretical carrier transport models, and are of practical importance in estimating the ultimate speed performance of surface MOSFET’s. An empirical model for usal as a function of temperature has also been derived for application in predictive device simulation. © 1990 IEEE