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.