6 MeV electron irradiation effects on electrical properties of Al/TiO2/n-Si MOS capacitors

The irradiation effects of 6 MeV electrons on the electrical properties of Al/TiO2/n-Si metal–oxide–semiconductor capacitors have been investigated. Nine Al/TiO2/n-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 30 kGy 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.

► The electron irradiation effects make variation in the device parameters.
► The device parameters changes due to percentage of defects and charge trapping.
► Leakage current of Al/TiO2/n-Si changes due to interface dangling bonds.
► The leakage current mechanism of MOS structures is due to Poole–Frenkel effect.