Epitaxial Regrowth and Hole Shape Engineering for Photonic Crystal Surface Emitting Lasers (PCSELs)

• Published in: Journal of crystal growth Vol. 535; no. C; p. 125531
• Main Authors: Reilly, Kevin J., Kalapala, Akhil, Yeom, Seuongwon, Addamane, Sadhvikas J., Renteria, Emma, Zhou, Weidong, Balakrishnan, Ganesh
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-2020; Elsevier BV; Elsevier
• Subjects: Crystal surfaces; Diameters; Electron beam lithography; Indium gallium arsenides; Inductively coupled plasma; Laser beams; Laser diodes; MATERIALS SCIENCE; Molecular beam epitaxy; Morphology; Nanostructures; Photonic crystals; Quantum well lasers; Semiconducting gallium arsenide; Surface emitting lasers; Voids; Molecular beam epitaxy; Nanostructures; Semiconducting gallium arsenide; Laser diodes
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2020.125531

•III-V void-semiconductor photonic crystal surface emitting laser.•Molecular beam epitaxy regrowth electron beam lithogrpahy.•Effects of regrowth on void/air-hole morphology infilling.
In the present research, epitaxial regrowth by molecular beam epitaxy (MBE) is investigated as a fabrication process for void-semiconductor photonic crystal (PhC) surface emitting lasers (PCSELs). The PhC is patterned by electron beam lithography (EBL) and inductively coupled plasma (ICP) etch and is subsequently regrown by molecular beam epitaxy to embed a series of voids in bulk semiconductor. Experiments are conducted to investigate the effects of regrowth on air-hole morphology. The resulting voids have a distinct teardrop shape with the radius and depth of the etched hole playing a very critical role in the final regrown void’s dimensions. We demonstrate that specific hole diameters can encourage deposition to the bottom of the voids or to their sidewalls, allowing us to engineer the shape of the void more precisely as is required by the PCSEL design. A 980 nm InGaAs quantum well laser structure is optimized for low threshold lasing at the design wavelength and full device structures are patterned and regrown. An optically pumped PCSEL is demonstrated from this process.