Temperature and scaling behavior of strained-Si N-MOSFET's

The device characteristics of N-MOSFETs fabricated in strained-Si have been investigated as a function of temperature and gate length. It is found that the low field mobility is enhanced compared to Si control devices at temperatures down at 20 K. For moderate fields, g/sub m/ is enhanced at all measured temperatures, for effective gate lengths down to 0.8 mu m (L/sub drawn/=1.5 mu m). At high power density, however, the devices exhibit a negative differential output resistance. The thermal conductivity of the relaxed Si/sub 1-x/Ge/sub x/ buffer layers is estimated by fitting polysilicon resistor characteristics to a first order model.