Process development to realize all-semiconductor InGaP-GaAs based photonic-crystal surface emitting lasers

P. Sammeta, P. Della Casa, O. Brox, J. Fricke, R.-S. Unger, D. Rentner, B. King, P. Crump, M. Weyers, A. Knigge, G. Tränkle

Published in:

Micro Nano Eng., vol. 30, pp. 100354, doi:10.1016/j.mne.2026.100354 (2026).

Abstract:

Semiconductor lasers are the most efficient devices for light generation. The Photonic Crystal Surface Emitting Laser (PCSEL) is a type of semiconductor laser that uses a 2D photonic crystal (PC) structure acting as the lateral cavity. The 2D photonic crystals realized in this work consist of a 150 nm thick InGaP layer containing a triangular pattern with a PC-lattice period of 320 nm. The transfer of the triangular pattern into InGaP is done through e-beam lithography followed by dry etching. Hydrogen silsesquioxane (HSQ) resist acts as mask during the etching process. A dry etch recipe is developed in this work to etch through the InGaP with minimum damage to the active region, which is at a distance of ~50 nm under the InGaP layer. Finally, the InGaP pillars are overgrown by MOVPE, thereby forming buried 2D features. The complete layer structure shows intense elec- troluminescence at target wavelength. The results obtained after the overgrowth pave the way for the fabrication of PCSELs with all-semiconductor integrated PCs with high optical coupling.

Keywords:

PCSEL, HSQ resist, InGaP pillars, PC features, Plasma etching, E-beam lithography

© 2026 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Rightslink® by Copyright Clearance Center

Full version in pdf-format.