New Technique for Sublimation Growth of AlN Single Crystals
Y. Shi, B. Liu, Lianghong Liu, J.H. Edgar
Kansas State University, Department of Chemical Engineering
E.A. Payzant
Oak Ridge National Laboratory, High Temperature Materials Laboratory
J. M. Hayes, Martin Kuball
University of Bristol, H. H. Wills Physics Laboratory
This article was received on Thursday, January 11, 2001 and
accepted on Sunday, March 4, 2001. Abstract
Single
crystalline platelets of aluminum nitride (AlN) were successfully grown by a
new technique. It consists of (1) depositing an AlN buffer layer on a SiC
substrate by metal organic chemical vapor deposition (MOCVD) below
1100°C, (2) forming an (AlN)x(SiC)1-x alloy
film on the AlN film by condensing vapors sublimated at a temperature of
1800°C from a source mixture of AlN-SiC powders, followed by (3)
condensing vapors sublimated from a pure AlN source (at 1800°C). The
necessity of the first two steps for the successful AlN sublimation growth on
SiC substrate was illustrated by the initial nucleation studies of alloys on
SiC substrates with and without MOCVD AlN buffer layers: an AlN MOCVD buffer
layer leads to continuous, single grain growth mode; The
(AlN)x(SiC)1-x alloy film reduces the crack density
because its thermal expansion coefficient is intermediate between SiC and AlN.
X-ray diffraction (XRD) and Raman spectroscopy studies indicated the high
quality of the AlN single crystal.Outline
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Cite this article as: MRS Internet J. Nitride Semicond. Res. 6, 5(2001).
last updated Tuesday, January 10, 2006 2:43:23 PM.© 2001-2006 The Materials Research Society
