Journal of Crystal Growth, Vol.361, 103-107, 2012
Lift-off of epitaxial GaN by regrowth over nanoporous GaN
Lift-off of epitaxial GaN was demonstrated by regrowing GaN over nanoporous GaN that was formed by electrochemical etching. During the regrowth, significant deformation of nanopores was observed due to the migration of Ga atoms on the surface. The shape and length of nanopores influenced the deformation process and the formation of spherical voids. Small and non-aligned voids were formed from branched pores while well-aligned voids were produced from cylindrical pores. During the shape deformation, the aligned voids were connected to neighboring voids eventually forming connected empty space in GaN. Spontaneous lift-off of GaN epitaxial layer from the substrate was resulted. This phenomenon could be utilized for an alternative approach to the lift-off of a vertical light emitting diode. (C) 2012 Elsevier B.V. All rights reserved.