Interruption-assisted epitaxy of faceted p-InAs on buffered GaSb for terahertz emitters

Cyril P. Sadia, University of the Philippines Diliman
Joselito Muldera, University of the Philippines Diliman
Elmer S. Estacio, University of the Philippines Diliman
Armando S. Somintac, University of the Philippines Diliman
Arnel A. Salvador, University of the Philippines Diliman
Christopher T. Que, De La Salle University, Manila
Kohji Yamamoto, University of Fukui
Masahiko Tani, University of Fukui

Abstract

We demonstrate molecular beam epitaxy growth of p-InAs layers on GaAs-buffered GaSb that may be suitable for terahertz applications. GaAs buffer deposition is initiated by applying growth interruption. Reflection high-energy electron diffraction shows that GaAs growth proceeds to a quasi-two-dimensional growth mode. The scheme allows growth of a p-InAs layer 600nm to 1.0 μm thick. Growth performed without GaAs and growth interruption resulted in decomposition of the p-InAs. When the scheme is used, the ensuing p-InAs first follows quasi-two-dimensional growth before favoring faceted islanding. Under 800-nm-wavelength femtosecond laser excitation, the p-InAs layer generates terahertz signals 70% of that of bulk p-InAs. © 2015 The Japan Society of Applied Physics.