Selective etching of dislocations in GaN and quantitative SEM analysis with shape-reconstruction method.
Due to the differences in etch-pit morphologies, chemical etching offers a possibility to determine densities of dislocations in respect to their type. In the present paper we propose a method, which implements a simple shape-from-shading procedure, i.e. with results derived from image brightness dependence on surface slope. It allows estimation of etch-pit depth distributions from scanning electron microscopy micrographs. This method is used to obtain depth distributions from GaN surface after etching in molten KOH-NaOH eutectic mixture. Depth distributions are used to estimate densities of etch-pits related to a given dislocation type. The distributions are compared with dislocation densities determined with transmission electron microscopy.
Wzorek
M
M
Institute of Electron Technology, Al. Lotników 32/46, 02-668 Warszawa, Poland. mwzorek@ite.waw.pl
Czerwinski
A
A
Ratajczak
J
J
Dylewicz
R
R
Katcki
J
J