Applications of the image processing method on the structure measurements in porous GaN

Porous GaN films on sapphire (0001) prepared by ultraviolet-assisted electrochemical etching and their quantitative structural characteristics based on mathematical morphology analysis using scanning electron microscope (SEM) images are reported in this study. The evaluation of porous GaN quality can be performed through a non-destructive investigation of its nanostructures using adapting image analysis techniques to obtain rapid, objective and quantitative information. The algorithm used for this work was implemented using the MATLAB software. The distributions of the maximum, minimum and average radii of the pores were obtained. Moreover, the porosity of the structures was obtained by calculating the areas occupied by the pores. SEM micrographs indicated that the shapes of pores for all porous samples were nearly hexagonal. The quantitative results were obtained and related with the characteristics of the fabrication process, showing reliability and promise in the control of pores over the formation process.