Leaky spots in irradiated SiO/sub 2/ gate oxides observed with C-AFM

A conductive atomic force microscope (C-AFM) has been used to perform a nanometer scale characterization of the electrical properties of irradiated thin SiO/sub 2/ gate oxides of MOS devices. The results have been compared to those obtained on fresh (without irradiation) and electrically stressed oxides. The electrical images reveal the existence of weak spots, which have been attributed to the electrical damage induced by irradiation. Their I-V characteristics have been registered with the C-AFM. The results show that they have a leaky behaviour, which has been associated to the radiation induced leakage current (RILC).