Surface Treatment and Layer Structure in 2H-GaN Grown on the (0001)Si surface of 6H-SiC by MBE
P. Ruterana, Philippe Vermaut , G. Nouet
Laboratoire d'etude et de recherche sur les materiaux, CNRS
A. Salvador, H. Morkoç
Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign
This article was received on June 11, 1997 and
accepted on September 26, 1997. Abstract
Heteroepitaxy
of hexagonal symmetry materials is more complicated than in the more usual case
of cubic systems. In the growth of layers on the (0001) surfaces, the misfit
dislocations always exhibit a screw component that leads to rotation of the
epilayer in a 3 dimensional growth mode. The size of the islands will depend on
many factors among which the substrate surface treatment, prior to growth, may
be a predominant one. In this work, a comparative study is carried out for
samples grown on plasma treated samples, with and without additional substrate
annealing prior to epitaxy. It is found that the defect density can be brought
below 109 cm-2, which is better than one order of
magnitude in comparison to the layers grown on sapphire substrates. On top of
the annealed substrates, the island growth is not obvious. Whereas,
misorientations as large as a few degrees can be measured inside the layers on
top of non annealed substrates, justifying the occurrence of high densities of
threading dislocations. Outline
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Cite this article as: MRS Internet J. Nitride Semicond. Res. 2, 42(1997).
last updated October 27, 1997 4:48:01 PM.© 1997 The Materials Research Society
