Miniaturization of Si MOSFET´s at 77 K

Micrometer and submicrometer dimension Si MOSFET´s have been studied at liquid nitrogen temperature. The emphasis of the study has been on the changes in the minimum channel length required for long-channel behavior Lmindue to cooling. It is found that there is a reduction in Lminwhich is quite considerable in MOSFET´s with low-channel doping. We have shown that this effect is due to a shorter lateral depletion width, and therefore longer effective channel length at low temperatures. A drastic decrease in punchthrough current has also been observed.