Morphological and structural characteristics of Gallium Nitride (GaN) porosity using image processing

Abstract

Attaining a generalized porosity measurement based on the conventional measuring methods is unfeasible due to thin and complex layers on Gallium Nitride (GaN) film. Therefore, there is an impetus for developing a method of estimating general fabric porosity via image processing techniques. This study is aimed to investigate and validate a new technique for extracting the GaN porosity in terms of morphological and structural characteristics using an image processing technique. The anodization on porous GaN films is prepared by using direct current photo-assisted electrochemical etching (DC-PECE) etching technique. The quantitative structural characteristics based on mathematical morphology is analyzed using Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM). To validate the method, the evaluation of porous GaN quality is performed through a non-destructive investigation of its nanostructures using adapting image analysis techniques. Porosity of the structures obtained by calculating the areas occupied by the pores. The quantitative results were obtained and showing good agreement between two modes of measurement and calculation (percentage porosity and pore depth) based on the image-processing data with 91 % and 78 % correlation coefficient.