TEMPERATURE-DEPENDENCE OF MOSFET SUBSTRATE CURRENT

Hitherto, theoretical models for MOSFET substrate current predicted th at substrate current is a strong function of temperature. However, exp erimental data presented in this and previous studies show that the ra tio of substrate current to drain current is insensitive to temperatur e over the range 77 to 300 K. We propose a modified model for an elect ron mean-free path (MFP) in the substrate current based on the concept of energy relaxation. The difference between the energy and momentum relaxation MPF is clarified and the substrate current model with modif ied MFP can explain the temperature dependence of the substrate curren t.