Compositional mapping of GaSb wafers from as-grown crystals and after post-growth annealing treatments

Dutta, PS and Marin, C and Dieguez, E and Bhat, HL (1996) Compositional mapping of GaSb wafers from as-grown crystals and after post-growth annealing treatments. In: Journal of Crystal Growth, 160 (3-4). pp. 207-210.

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Abstract

Spatial compositional analysis has been carried out on single and polycrystal wafers of GaSb grown from stoichiometric and non-stoichiometric melts. In crystals grown from stoichiometric melt, the ratio of Ga to Sb is slightly more and remains uniform throughout. At the grain boundaries in polycrystals, the Sb content is more than in the other regions of the crystal. Crystals grown from either Ga- or Sb-rich melts exhibit inclusions of the excess component. Post-growth annealing treatments in vacuum and Ga-rich atmospheres have been performed. Heat treatments in vacuum atmosphere produce very little effect on the local composition of the crystal. On the other hand, localized crystallization at grain boundaries and inclusions takes place in the presence of excess gallium. It has been shown that annealing treatments in Ga ambient can produce defect-free wafers with extremely homogeneous composition. It is concluded that the excess Sb which is liberated from the crystal during growth resides at the grain boundaries and other extended defect centers. The vacant Sb sites are then responsible for the formation of the native acceptor centers like $V_{Ga}$ and $Ga_{sb}$.

Item Type:	Journal Article
Publication:	Journal of Crystal Growth
Publisher:	Elsevier
Additional Information:	Copyright of this artcile belongs to Elsevier.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	12 Jan 2007
Last Modified:	19 Sep 2010 04:33
URI:	http://eprints.iisc.ac.in/id/eprint/9298

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