Generation of Interface States by Ionizing Radiation at 80K Measured by Charge Pumping and Subthreshold Slope Techniques

Generation of fast interface states D11 by ionizing radiation has been measured in MOS transistors at 80K and 295K using charge pumping and subthreshold slope techniques. Using charge pumping, the more sensitive and reliable technique, we find that D11 are not formed by radiation at 80K. In contrast, subthreshold slope measurements appear to show an increase in D11 in MOSFETs irradiated at 80K. This is shown to be an artifact caused by lateral non-uniformities (LNU) in the radiation-induced fixed charge.