Response of RADFETs to Photon Ionizing Radiation and Subsequent Recovery at Room and Elevated Temperature

The paper presents the experimental results of the response of RADFETs with an oxide thickness of 1 μm during irradiation and subsequent recovery at room and elevate temperatures. First, the results of the influence of energy of photons ionizing radiation on the threshold voltage shift for the absorbed radiation dose interval from 1 to 5 Gy are shown. It is shown that with a decrease in the energy of ionizing radiation, the value of threshold voltage shift increases and that this increase is a consequence of the increase in traps where positive charge in the oxide captured. Recovery of previously irradiated RADFETs by gamma radiation up to 5 Gy at room and elevated temperatures was also investigated. It was shown that there is no loss of dosimetric information during 20 h recovery at room temperature. Recovery at a temperature 150 °C for 500 h leads to an almost complete loss of dosimetric information, which manifests itself as the value of the threshold voltage shift being approximately equal zero. It was also shown that pre-irradiation of RADFETs up to an absorbed radiation dose of 10 mGy and recovery at room temperature leads to a significant increase in the sensitivity of these components to ionizing radiation.