MOVPE growth of highly strained InGaAs/GaAs quantum wells

The indium incorporation into strained InGaAs quantum wells grown on GaAs substrate by metalorganic vapour-phase epitaxy is found to be reduced in comparison to relaxed layers. Additionally, the indium uptake into strained QWs is limited to approximately 30% InAs at 650 degrees C. Excessive trimethyl indium supply in the vapour phase leads to a drop of the In-content of the QW and to a reduced total In-content in the whole structure. Only a small amount of the excess indium is incorporated into InAs-rich clusters observed as dark-spot defects and into a graded interfacial layer. A model for this behaviour based on the enhanced In-reevaporation from In-rich areas is presented. (C) 1998 Elsevier Science B.V. All rights reserved.