ISSN:
1432-0630
Schlagwort(e):
61.14.−x
;
61.70.At
;
68.55.−a
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
,
Physik
Notizen:
Abstract Threading dislocation morphologies and characteristics have been investigated in 3 μm thick GaAs films with ultrathin (∼1 nm) Si interlayers grown by molecular beam epitaxy on tilted (2° toward [110]) Si (001) substrates using cross-sectional transmission electron microscopy. Four sample structures are studied in which different numbers of ultrathin Si layers are grown at different positions in the GaAs film, and the results are compared for samples observed before and after ex situ annealing. In all of the sample structures, some mixed-type dislocations are clearly blocked by the Si interlayers, although some of them pass through these layers, resulting in propagation of their threading dislocations to the sample surface. After annealing at 900 °C for 10 s or 800 °C for 30 min, the interactions of the dislocations with the interlayers are enhanced, and there is an increase in the number of dislocations which are bent along the 〈110〉 directions at the positions of the Si barrier layers. However, a considerable number of dislocations still escape from the Si barriers by gliding on {111} slip planes during annealing. Moreover, ex situ annealing generates new edge-type dislocations through interactions between moving threading dislocations. The nature of the dislocations that cross the Si barriers is especially discussed.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00332171
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