The Effects of Electron and Hole Trapping on the Radiation Hardness of Al2O3 MIS Devices

The radiation sensitivity of MIS capacitors with pyrohydrolytic A12O3 insulators has been investigated for X-irradiation at 300 and 80K. Both X-rays and light of various photon energies were used to vary the populations of electron and hole traps inherent in the "as prepared" films. The energies of the trapping levels have been determined and the spatial distribution of the electron traps within the oxide estimated. These traps together with an SiOx layer at the semiconductor-oxide interface are shown to control the device behavior under ionizing radiation.