A Method for the Determination of High‐Field Conduction Laws in Insulating Films in the Presence of Charge Trapping

The investigation of high‐field electronic conduction in metal‐insulator‐metal (MIM) or metal‐insulator‐semiconductor (MIS) structures utilizing dc methods is frequently complicated by the fact that the observed currents decay with time. In cases where this time dependence is caused by charge trapping in the insulating film, the most direct study of conduction involves a determination of the initial current, i.e., that which flows before charging becomes significant. Direct observation of this current is sometimes difficult because the onset of trapping can occur within either a very short time or a very short distance. In films characterized by trapping, the initial current can be determined by monitoring the time dependence of the charging process itself. This method requires the use of an MIS structure with a nondegenerate semiconductor, usually serving as a cathode. The state of charge of the insulator is determined by measuring the MIS flat‐band voltage. The calculation, which assumes that the trappi...