Optimization of a single-step reactive ion etching process for InP photonic integration

In this contribution we present a novel single-step reactive ion etching process based on CH4/H2 chemistry. Unlike the traditional RIE process, the single-step process does not require cycles iterated with O2 plasma to control the polymerization. The optimization is achieved by balancing the isotropic and the vertical anisotropic etching. The final process provides high selectivity, smooth etched profiles and small sidewall angles, and can be a perfect solution for etching InP membrane waveguides.