The application of the Methods of Cathodoluminescence and Photoluminescence for Non-destructive Testing of AlGaN Heterostructures

This paper examines cathodoluminescence spectra of samples on sapphire substrates to develop methods of non-destructive testing of wafers with AlGaN/GaN heterostructures. It has been determined that the cathodoluminescence peak of AlGaN compound was demonstrated for decreased energy of excitation electrons (at 0.5 eV and 1 keV) only. Cathodoluminescence peak of AlN compound with energy of 6.15 eV was demonstrated at any excitation energy of 0.5 to 6.15 eV. It has been demonstrated that cathodoluminescence spectrum analysis allowed determining aluminum percentage in AlGaN, which was essential for inward testing of wafers for microwave transistors production. Data on the intensity distribution of "yellow" photoluminescence over the wafer surface has been obtained, and it has been demonstrated that these measurements were a prospective method of non-destructive testing to sorting wafers by defects.