Hot Electrons in Si(100) Inversion Layer at Low Lattice Temperatures

The hot electron effect at low lattice temperatures 1≤ T ≤30 K is studied on the assumption that, in addition to the phonon scattering and some residual scattering independent of T , there is an unknown mechanism which limits the electron mobility such that µ -1 ( T e , T )=µ RES -1 +µ ph -1 ( T e , T )+µ ? -1 ( T e ), where T e is the electron temperature. µ ? -1 ( T e ) is determined by requiring that µ -1 ( T e , T ) reproduces the measured low field mobility. The field dependence of µ( T e , T ) is deduced from the usual energy balance consideration and it is concluded that the dependence can provide a crucial test for the existence of µ ? -1 ( T e ) for it should be noticeably weaker if there were no such unknown mechanism.