Total Ionizing Dose Effects on Silicon Ring Resonators

The performance of silicon ring resonators exposed to 10-keV X-ray and 662-keV gamma radiation is reported. Unpassivated rings having no native oxide exhibit a blue-shift in resonance wavelength with increasing total dose, which is attributed to surface oxidation that is accelerated in the presence of high energy radiation. Unpassivated rings exposed to 145 krad(SiO2) of 10-keV X-rays or gamma rays exhibit blue-shifts significantly larger than the full-width at half-maximum of the resonance, leading to a more than 10 dB change in transmission. No changes in the transmission of passivated rings were observed upon irradiation. Therefore, passivated rings can function as radiation-tolerant elements in optoelectronic circuitry.