Experimental investigation of dewetting models

A series of experiments was performed in order to look at the solid–liquid interface and meniscus region in dewetted Bridgman growth of GaSb and InSb in silica crucibles. In agreement with theoretical models, they show that a very stable dewetting was obtained for GaSb only if an oxidising atmosphere is present in the ampoule, and that it increased the wetting and growth angles. Stable dewetting of InSb was never obtained, which can be explained by wetting and thermodynamic considerations. Experiments with an easily dissolved gas (H2) have shown that a model of dissolution–rejection of ampoule gas cannot explain dewetting. Also the formation of hillocks has been observed. Finally, the self-stabilisation of the gas pressure difference is confirmed but remains largely unexplained.