DYNAMICS OF SURFACE-CHARGE REGION OF THIN INSULATOR N-TYPE MOS STRUCTURES

A simple model that relates the dynamics of the surface charge region of a thin insulator N-type metal-oxide-semiconductor (MOS) structure t o Fowler-Nordheim tunnelling injection is presented. The main effect o f Fowler-Nordheim tunnelling injection on the MOS capacitance-time cur ves is that the capacitance in the heavy inversion region approaches t he low frequency value as the gate voltage is increased. Two relaxatio n stags and two basic mechanisms responsible for the time-dependent ca pacitance under Fowler-Nordheim tunnelling injection are described. Th e model developed from the surface charge relaxation is shown to agree with the experimental data over a wide range of applied electric fiel ds.