Fabrication of high quality factor photonic crystal microcavities in InAsP∕InP membranes combining reactive ion beam etching and reactive ion etching

The process of fabrication of high quality factor photonic crystal microcavities in slabs of InP with light emission at 1.5μm is reported. The process includes e-beam lithography, reactive ion beam etching with a CHF3∕N2 gas mixture, and reactive ion etching with a CH4∕H2 gas mixture and O2 cycling. An InGaAs sacrificial layer is removed by chemical wet etching in order to obtain the photonic crystal membrane. Microphotoluminescense measurements have been performed to assess the quality of the fabricated structures. Quality factors up to ≃30000 and laser emission with thresholds of excitation pump power around 34μW have been obtained.