Degradation of Mis Devices Under Electron Bombardment

The behavior and physics of failure of MIS devices under irradiation with energetic electrons was investigated. It was found that the bombardment usually results in the introduction of positive charge in the insulator. This effect is explained by a physical model which involves interaction of secondary electrons with the insulator lattice to generate electron-hole pairs and predominant trapping of holes in the insulator. The dependence of the radiation sensitivity on pre-bombardment surface state density, device parameters, and fabrication procedure, as well as the annealing behavior was studied.