Abstract
The effects of electron beam irradiation on p or n channel enhancement type MOS transistors, both prepared by the dry oxidation method have been investigated. The threshold voltage VT. shifts to negative side with the increase of irradiation dose. The result can be explained by the positive charges accumulated at the SiO2-Si interface.
At the doses beyond 1014 elecrons/cm2, however, the threshold voltage shifts to positive side with the increase of irradiation doses. The result can not be explained by the positive charges only. In order to explain the result satisfactorily, the idea of“electron-trapping centers”has been introduced.
The effective length (distance from SiO2-Si interface) over which the positive charges collect was estimated at 410Å.
