Inductively coupled plasma etching of high aspect ratio two-dimensional photonic crystals in Al-rich AlGaAs and AlGaAsSb

Planar two-dimensional photonic crystals are key tools for the development of advanced optoelectronic devices. However, their practical realization often requires deep etching of air holes with high aspect ratio. In this article, the authors report on a time-multiplexed inductively coupled plasma reactive ion etching technique, allowing deep etching of AlGaAs and AlGaAsSb heterostructures. Air holes of 130 nm wide and 1.85 μm deep have been realized in AlGaAs heterostructures with up to 60% Al.