Characterization of field-effect mobility at optical frequency by microring resonators

A novel characterization method is proposed to extract the optical frequency field-effect mobility (mu(op,FE)) of transparent conductive oxide (TCO) materials by a tunable silicon microring resonator with a heterogeneously integrated titanium-doped indium oxide (ITiO)/SiO2/silicon metal-oxide-semiconductor (MOS) capacitor. By operating the microring in the accumulation mode, the quality factor and resonance wavelength shift are measured and subsequently used to derive the mu op, FE in the ultra-thin accumulation layer. Experimental results demonstrate that the mu(op,FE) of ITiO increases from 25.3 to 38.4 cm(2).V-1.s(-1) with increasing gate voltages, which shows a similar trend as that at the electric frequency. (C) 2021 Chinese Laser Press

Automated summary

A novel characterization method using a tunable silicon microring resonator and ITiO/SiO2/MOS capacitor is proposed to extract the optical frequency field-effect mobility of TCO materials, demonstrating real-time monitoring of mu(op,FE).