Abstract
A technique is described which allows direct characterization of deep centers in an insulator slab sandwiched between doped semiconducting layers. It is based on transient conductivity measurements, on devices biased in the high-injection regime, and relies on the modulation of the barrier height under carrier trapping or detrapping of deep levels present in the insulator. It offers the advantage of a higher sensitivity than in capacitance techniques if the semiconductor contacting layers are heavily doped, and it allows the determination of the influence of deep centers on current voltage (I-V) curves (e.g., hysteresis) when the sample is leaky. Numerical simulations of the current-transport processes are carried out, in order to demonstrate the validity of the technique and to show the limits of its applicability.