ISO/AWI 5618-3

Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for GaN single crystals — Part 3: Method of X-ray rocking curve measurement

Scope

This document specifies the test method for quality evaluation of freestanding GaN (0001) substrates or wafers with epitaxial GaN (0001) layers by the X-ray rocking curve (XRC) method. This method is also applicable to GaN (0001 ̅) that are crystallographically symmetric.
This document provides two methods to be used depending on the quality or feature.
“Wafer characterization XRC measurement” shall be adopted to evaluate wafer-scale quality of high quality GaN wafers. This method gives a compositive characterization of crystal imperfections in a wide area, such as crystal mosaicity, lattice bowing, and macroscopic plane orientation distribution at the wafer level, by expanded X-ray irradiation area.
“Local mosaicity XRC measurement” can be adopted to evaluate local area crystal mosaicity by eliminating the effects of lattice bowing and macroscopic plane orientation distribution. This method gives a simple evaluation of crystal mosaicity by restricting the area measured.