Enhanced Generation of Interface States in MIS IC Elements under the Action of UV and X-ray Radiations

Abstract

The effect of enhanced generation of states at the Si/SiO2 interface was first observed in polySi-gate MIS structures successively subjected to UV and X-ray radiations. It was studied on test MIS transistors of series-produced ICs by the methods of subthreshold currents, charge pumping currents, and internal photoemission. A possible reason for enhanced generation of the states is the presence of hydrogen at the interface with the polySi gate. Under UV irradiation, the hydrogen diffuses toward the substrate and causes surface state generation under subsequent irradiation by X-rays.