Effect of radiation-induced charge on 1/f noise in MOS devices

The 1/f noise in MOS transistors is measured as a function of gate and drain bias, total ionizing dose, and postirradiation biased annealing time. The transistors tested varied in size, radiation hardness, and process technology. The radiation-induced 1/f noise correlates strikingly with the oxide trap charge through irradiation and anneal, but not with interface-trap charge, for frequencies up to 10 kHz. This implies that oxide trapped charge is the predominant factor which leads to the increased 1/f noise in irradiated MOS devices.>