UNIFORMITY IN (HG, MN)TE FILMS GROWN BY METALORGANIC VAPOR-PHASE EPITAXY

Epitaxial layers of Hg1-xMnxTe have been grown by metalorganic vapour phase epitaxy on (100) GaAs substrates using both direct alloy growth (DAG) and the interdiffused multilayer process (IMP). The variation in composition, layer thickness and X-ray rocking curve width over the s ample have been assessed by double crystal X-ray diffraction. These me asurements show that uniformity in IMP layers is superior to that in D AG material. An approximate model assuming a constant ''plug'' velocit y profile is developed and used to provide a qualitative explanation o f why compositional uniformity is poor in DAG layers.