Danilewsky, AN;Croll, A;Tonn, J;Schweizer, M;Lauer, S;Benz, KW;Tuomi, T;Rantamaki, R;McNally, P;Curley, J

2009

October

Crystal Research and Technology

Dislocations and dislocation reduction in space grown GaSb

Published

3 ()

FLOATING-ZONE TOPOGRAPHY GAAS

44

1109

1114

The behaviour of dislocations in GaSb crystals grown in space both from a stoichiometric melt (floating zone method, FZ) and a Bi solution (floating solution zone, FSZ) respectively, is studied. Predominantly straight 60 degrees dislocations with Burgers vectors of the type b = a/2 < 110 > in (111) glide planes are identified. In the 20 mm long FZ single crystal the linear growing out of the dislocations is observed which reduces the dislocation density in the centre of the crystal to values below 300 cm(-2). The Bi incorporation in the FSZ crystal results in a misfit between seed and grown crystal and in a network of misfit dislocations at the interface. Thermocapillary convection during growth as well as the surface tension may be the reasons for the presence of curved dislocations and the higher dislocation density within a 1 - 2 mm border region at the edges of both of the crystals.

WEINHEIM

0232-1300

10.1002/crat.200900468