Process optimization for dry etching of InP-InGaAsP-based photonic crystals with a Cl/sub 2//CH/sub 4//H/sub 2/ mixture on an ICP-RIE

Etching photonic crystals (PhCs) in InP/InGaAsP requires a process with high selectivity against the mask for the fabrication of about 2 /spl mu/m deep holes as required for PhCs in a low refractive-index-contrast material system. We etch PhCs with a Cl/sub 2//CH/sub 4//H/sub 2/ gas mixture on an ICP-RlE system. In this paper, we present our fabrication technology and discuss the influence of the mask material and layer composition on the etched hole shape.