Diffusive Representation and Sliding Mode Control of Charge Trapping in Al$_2$O$_3$ MOS Capacitors

The objective of this paper is to introduce a modeling strategy to characterize the dynamics of the charge trapped in the dielectric of MOS capacitors, using diffusive representation. Experimental corroboration is presented with MOS capacitors made of Alumina in three different scenarios. First, the model predictions are compared with the trapped charge evolution due to arbitrary voltage excitations. Second, the predictions are compared with the measurements of a device in which a sigma-delta control of trapped charge is implemented. Finally, the time evolution when the device is simultaneously controlled and irradiated with X-rays is compared with the predictions. In all cases, a good matching between the models and the measurements is obtained.