Growth of GaSb / AlSb heterostructures on patterned substrates by molecular beam epitaxy

• Published in: Journal of crystal growth 1994-10, Vol.143 (1), p.1-6
• Main Authors: Walther, M., Kramer, G., Tsui, R., Goronkin, H., Adam, M., Tehrani, S., Rogers, S., Cave, N.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Iii-v semiconductors; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/0022-0248(94)90360-3

InAs / AlSb / GaSb heterostructures with excellent morphological and electrical properties were regrown for the first time on dry-etched GaAs substrates and GaSb epilayers. The shape of the overgrown structures is determined by the adatom species, the crystallographic direction and the growth parameters. For stripe orientations in [011], [001] and [0 1 1] directions, only (111), (110) and (100) planes are formed near the stripe edges. No higher index facets were observed, in contrast to regrowth of GaAs / AlGaAs heterostructures on patterned wafers. Significant differences in growth rates are observed for GaSb and AlSb on (111)A and (111)B facets. On (111)A planes, GaSb and AlSb grow with nearly the same growth rate. However, the growth rate of GaSb on (111)B facets is drastically reduced due to the enhanced migration of Ga from (111)B planes to (100) planes with a higher sticking coefficient for Ga. No degradation of the electrical properties of InAs quantum well structures is observed after regrowth on dry-etched GaSb epilayers, thus proving the suitability of the patterning process.