Study of NMOSFET substrate current mechanisms in the temperature range of 77-295 K
Substrate-current mechanisms in NMOSFET's in the range of 77-295 K are investigated. It is found that electron mean-free path is temperature independent with a value of about 7.6 nm. Although the maximum channel electron energy at low temperatures is a little larger than at 295 K the reduced impact ionization results in an increase of the substrate current less than one order of magnitude. With these mechanisms, simulation and experiment are in a fairly good agreement.