Defect and emission distributions in bulk GaN grown in polar and nonpolar directions: a comparative analysis
2008 (English)In: Proceedings of SPIE - The International Society for Optical Engineering, 2008, 68940D1- p.Conference paper (Refereed)
We have investigated bulk GaN material grown by HVPE either in the conventional polar  direction and subsequently sliced with nonpolar surfaces or grown in the nonpolar [11-20] direction. Spatially resolved techniques such as cathodoluminescence imaging and transmission electron microscopy, as well as profile measuring techniques such as positron annihilation spectroscopy and secondary ion mass spectroscopy were employed to directly visualize the extended structural defects, and point defect (impurity and vacancy) distributions along the growth axes. A comparative analysis of the results shows a distinctive difference in the distribution of all kind of defects along the growth axes. A significant decrease in the defect density in material grown along the polar direction, in contrast to the constant behavior of the high defect density in material grown along the nonpolar direction points out the low-defect superior quality of the former material and indicates the preferable way of producing high-quality GaN substrates with nonpolar surfaces.
Place, publisher, year, edition, pages
2008. 68940D1- p.
National CategoryNatural Sciences
IdentifiersURN: urn:nbn:se:liu:diva-42156DOI: 10.1117/12.767628Local ID: 60918OAI: oai:DiVA.org:liu-42156DiVA: diva2:263011
International Symposium on Integrated Optoelectronic Devices Photonics West 2008,2008