Dislocation analysis of epitaxially grown GaN was performed by using an HCl vapor phase etching process. The effects of the major process parameters temperature, pressure and gas composition were studied in detail. For reliable results a large size of the etch pits was required, but a merging of the pits had to be avoided. A temperature of 600C, a reactor pressure of 940mbar and an HCl concentration of 10% lead to best results and highest etch rates, respectively.

Determination of Dislocation Density in Epitaxially Grown GaN using an HCl Etching Process. F.Habel, M.Seyboth: Physica Status Solidi C, 2003, 0[7], 2448-51