Impact of Gamma Ray and Neutrons Radiation Effects on Al/SiO2/Si Structure

The metal-oxide-semiconductor (MOS) structure was fabricated from p-type (Boron doped) SSP silicon <100>. The interfacial oxide layer was SiO2 while aluminium's metal gate thickness was (~250 nm) thermally evaporated with silver contacts. Four of the prepared structures were exposed to gamma radiation from the Ra226 source with a duration of (10, 20, 30, 40) days respectively, while another four structures were exposed to neutrons irradiation using (241Am -10Be) source for (5, 7, 9, 12) days respectively. The last MOS was not exposed to any radiation. Characterization measurements were carried out to compare the behaviour of MOS structures after being irradiated. The main result is that there is a significant increase in the current due to the decrease of barrier height of irradiate MOS devices as well and C-V measurements illustrate negative voltage shifts in the irradiated devices as a result of the buildup of interface states and the generation of electron-hole pair as a result of the radiation.