Nanoscale bias-annealing effect in postirradiated thin silicon dioxide films observed by conductive atomic force Microscopy

This paper investigated the reliability of thin silicon dioxide (SiO2) subjected to irradiation followed by stress, using conductive atomic force microscopy (C-AFM). The I-V characteristics of localized spots on thin oxide films were measured before and after Co-60 gamma-ray irradiation. The oxide films were then subjected to a ramped voltage stress simultaneously during the I-V measurements. By taking advantage of a small contact area, we report for the first time the nanoscale postirradiation bias-annealing effect in thin S film using C-AFM. Based on SiO2 the number of fluctuating current peaks appearing in the I-V curves of the pre- and posttreatment oxide films, as well as the calculated effective barrier height from the Fowler-Nordheim tunneling theory, we found that the trapped charge in the oxide films, but not the charge at the interface caused by Co-60 gamma-ray irradiation, can be effectively annealed out by a postirradiation ramped voltage.