The Effect of Ion Implantation on Oxide Charge Storage in MOS Devices

Measurements are reported in which the charge stored in the oxide of an MOS device exposed to ionizing radiation is studied as a function of oxide pretreatment. Implantation with Al+ ions is found to introduce electron traps into the oxide and the stability of these traps is examined in thermal annealing experiments. The predictions of a simple model, in which the implantation associated displacement damage is considered to be the source of the additional electron traps, is compared to the experimental observations.