Shape stability of InAs self-assembled islands on vicinal GaAs(001) substrates

We have grown InAs self-assembled islands on vicinal GaAs( 001) substrates. Atomic force microscopy and photoluminescence studies show that the islands have a clear bimodal size distribution. While most of the small islands whose growth is limited by the width of one multi-atomic step have compact symmetric shapes, a large fraction of the large islands limited by the width of one step plus one terrace have asymmetric shapes which are elongated along the multi-atomic step lines. These results can be attributed to the shape-related energy of the islands at different states of their growth. (C) 2008 Elsevier B. V. All rights reserved.

National Natural Science Foundation of China 60706009 90401025607360366077702160476009National Key Basic Research Program of China 2006CB604901 2006CB604902 National High Technology Research and Development Program of China 2006AA01Z256 2007AA03Z419 2007AA03Z417 This work was supported by the National Natural Science Foundation of China ( Grant Nos. 60706009, 90401025, 60736036, 60777021, 60476009), the National Key Basic Research Program of China (Grant Nos. 2006CB604901, 2006CB604902) and the National High Technology Research and Development Program of China (Grant Nos. 2006AA01Z256, 2007AA03Z419, 2007AA03Z417).