Laterally modulated composition profiles in AlAs/InAs short-period superlattices
- National Renewable Energy Laboratory, Golden, Colorado 80401-3393 (United States)
- Sandia National Laboratories, Albuquerque, New Mexico 87185-1056 (United States)
Laterally modulated composition profiles in AlAs/InAs short-period superlattices grown by molecular-beam epitaxy under tensile strain on (001) InP are examined by transmission electron microscopy (TEM) and x-ray diffraction {ital K} mapping. Weak, one-dimensional modulation with a wavelength of {lambda}{sub m}=110thinsp{Angstrom} is observed for a period of 1 ML. At 2 ML, the composition profile is irregular, while a two-dimensional network of wire and dot structures with {lambda}{sub m}=130thinsp{Angstrom} occurs at 3 ML. At a high growth rate, 4-ML samples exhibit smooth modulated profiles with {lambda}{sub m}=220thinsp{Angstrom}. When the growth rate is reduced with beam interrupts, sharp profiles develop that show strong alignment in the substrate plane with {lambda}{sub m}=270thinsp{Angstrom}. TEM dark-field image contrast of the modulated profiles is simulated using dynamical diffraction theory to reproduce features observed in experiment. {copyright} {ital 1998 American Institute of Physics.}
- OSTI ID:
- 664664
- Journal Information:
- Journal of Applied Physics, Vol. 84, Issue 11; Other Information: PBD: Dec 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Lateral composition modulation in AlAs/InAs short period superlattices grown on InP(001)
Strain-dependent morphology of spontaneous lateral composition modulations in (AlAs){sub m}(InAs){sub n} short-period superlattices grown by molecular beam epitaxy