Radiation Damage in MOS Transistors as a Function of the Angle between an Applied Electric Field and Various Incident Radiations (Protons, Electrons, and Co-60 Gamma Rays)

Data is presented which shows that ionizing radiation damage produced by 2 to 16 MeV protons in MOS transistors, with applied electrical fields across the gate oxides, is dependent upon the angle between the fields and the incident protons. This angular dependency can be explained by the "columnar recombination model." For Co-60 photons and 5 to 20 MeV electrons, the data shows no angular dependency.