Fabrication of high-aspect-ratio InP-based vertical-cavity laser mirrors using CH 4 / H 2 / O 2 / Ar reactive ion etching

• Published in: Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Vol. 15; no. 6; pp. 2031 - 2036
• Main Authors: Schramm, Jeff E., Babić, Dubravko I., Hu, Evelyn L., Bowers, John E., Merz, James L.
• Format: Journal Article
• Language: English
• Published: 01-11-1997
• Subjects: InP
• ISSN: 0734-211X; 1520-8567
• DOI: 10.1116/1.589219

The addition of oxygen to methane/hydrogen/argon reactive ion etching (RIE) processes can mitigate polymer deposition, and produce vertical etched sidewalls. This work contrasts the various ways in which the oxygen may be incorporated into methane/hydrogen/argon reactive ion etching of deep
(>
5 μm) InGaAsP/InP multilayers. Three methods are investigated: a “continuous” process in which a fixed amount of oxygen is added to methane/hydrogen/argon for the duration of the etch, a “cyclical” process in which the methane/hydrogen/argon RIE processes alternates with oxygen RIE, and a hybrid process which incorporates the advantages of both former methods. These processes are applied to the fabrication of tall
(>
10 μm) InGaAsP/InP quarter-wave mirrors for long-wavelength vertical-cavity lasers; the various benefits and limitations of the various approaches are discussed. It is found that the hybrid process allows formation of deeply etched structures (15 μm) with vertical profiles.