The surface deformation of undoped GaN epitaxial layer on sapphire(0 0 0 1) substrate has been studied by the nanoindentation of pointed diamond (Berkovich triangular pyramid) and spherically tipped diamond of 5 μm radius. We found a "pop-in" under the load portion of load-displacement curves for all the samples, and that average shear stress is dependent on the film thickness. We further calculated "true-hardness" of GaN on sapphire(0 0 0 1) substrate, and compared with the results of InGaN on sapphire.
|Number of pages||5|
|Journal||Journal of Crystal Growth|
|Publication status||Published - 1998 Jun 15|
- Shear stress
ASJC Scopus subject areas
- Condensed Matter Physics