Inductively coupled plasma etching of GaN using SiCl4/Cl2/Ar for submicron-sized features fabrication

• Published in: Physica status solidi. C Vol. 4; no. 7; pp. 2634 - 2637
• Main Authors: Dylewicz, R., Hogg, R. A., Fry, P. W., Parbrook, P. J., Airey, R., Tahraoui, A., Patela, S.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.06.2007; WILEY‐VCH Verlag
• Subjects: 42.79.Gn; 42.82.Cr; 42.82.Et; 52.77.Bn; 81.05.Ea
• ISSN: 1862-6351; 1610-1634; 1610-1642
• DOI: 10.1002/pssc.200674851

In this paper we report the optimization of the fabrication process of a grating coupler, which is fully integrated with a GaN planar waveguide. To our knowledge, this is the first report of a grating‐assisted optical coupler in gallium nitride. ICP dry etching of n‐doped GaN layers was investigated, where SiCl4/Cl2/Ar gas mixture was used under different etching conditions. We report n‐GaN ICP etching ratio of 520‐2680 Å min–1 as well as etching selectivity of GaN over SiO2 from 3 to 8, in the most cases. Grating ridge and grating groove width as well as the sidewalls slope were evaluated by SEM microscope. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)