武部敏彦
Facet Generation During Molecular Beam Epitaxy of GaAs/AlGaAs
Multilayers on GaAs (001) Patterned Substrates
Abstract:Extra facet generation during molecular beam epitaxy of GaAs/AlGaAs
multilayers on (001) GaAs substrates patterned with stripes running in the [110],
[110], and [100] directions and having various slopes, designated as "[110] stripe",
"[110] stripe", and "[100] stripe", respectively, has systematically been
investigated for the first time. It has been confirmed that extra (111)A and
(114)A facets generate on the [110] stripes, extra (111)B and
(113)B facets on the
[110] stripes, and extra (031), (011), (045), and (013) facets. on the [100] stripes,
depending on the intersection angle θ of the sidewall and the substrate plane.
Among them, the (114)A, (113)B, and (013) facets are important because they
persist over a wide range of θ and, therefore, play a detrimental role in forming
flat and uniform sidewall layers on the (001) patterned substrates. It has been
made clear that no extra facets generate on the sidewalls and flat and uniform
layers maintaining the initial as-etched stripe patterns can be grown for the
[110] stripes with 10°≧θ， the [110] stripes with 24゜≧θ≧20°, and the [100]
stripes with 19°≧θ. Extra (111)A-related facets have developed on the (111)A-related
intersection of the equivalent [100] and [010] stripes, while no extra
facets have developed on the (111)B-related intersection.