Selective Etching of GaN from AlGaN/GaN and AlN/GaN Structures
JA. Grenko, CL. Reynolds Jr, R. Schlesser, K. Bachmann, Z. Rietmeier, Robert F. Davis, Z. Sitar
Department of Materials Science and Engineering, North Carolina State University
This article was received on Wednesday, April 7, 2004 and
accepted on Wednesday, July 14, 2004. Abstract
Thick
GaN layers as well as AlGaN/GaN and AlN/GaN heterostructures grown by
metalorganic vapor phase epitaxy have been photoelectrochemically (PEC) etched
in various dilute electrolytes, and bandgap-selective etching has been
demonstrated in heterostructures. This result is a significant step forward in
the fabrication of group III-nitride devices and one-dimensional photonic
bandgap (PBG) structures in the deep UV. Based on initial results from thick
GaN layers, a method was developed to achieve self-stopping selective etching
of thin GaN layers in AlGaN/GaN and AlN/GaN heterostructures. Selective PEC
etching requires the use of a suitable light source with photon energies larger
than the bandgap of GaN, but smaller than that of AlGaN or AlN, thus enabling
selective hole generation in the GaN layers to be etched. Additionally, it is
imperative to use an electrolyte that supports PEC etching of GaN without
chemically etching AlGaN or AlN.Outline
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Cite this article as: MRS Internet J. Nitride Semicond. Res. 9, 5(2004).
last updated Wednesday, December 8, 2004 12:51:11 PM.© 2004 The Materials Research Society
