6 MeV electron irradiation effects on electrical properties of Al/TiO_2-Si MOS capacitors

摘要

The irradiation effects of 6 MeV electrons on the electrical properties of Al/TiO_2-Si metal-oxide-semiconductor capacitors have been investigated. Nine Al/TiO_2-Si capacitors were fabricated using radio frequency magnetron sputtering and divided into three groups. Groups were irradiated with 6 MeV electrons at 10, 20, and 30kGy doses, respectively, keeping the dose rate ~1 kGy/min. The variations in the capacitance-voltage and leakage current-voltage characteristics, in addition to the electrical parameters, such as conductance (G/ω), flat-band voltage, interface trap density and the surface charge density with electron dose were studied. The Poole-Frenkel coefficient of the MOS capacitors was determined from current-voltage characteristics. Possible mechanisms for the enhanced leakage current in the electron irradiated MOS capacitors are discussed.