Epitaxial InGaN with an In content of up to 89% was grown on a GaN template on a sapphire substrate using metalorganic chemical vapor deposition. The grown layer showed a bilayered structure of In- and Ga-rich InGaN parallel to the growth plane, as confirmed by both x-ray diffraction and electron microscopy. High-angle annular dark-field images revealed that pyramidal Ga-rich InGaN had formed on the top of the In-rich InGaN layer with an abrupt interface. Nucleation of the In-rich InGaN was believed to be related to threading dislocations stemming from the GaN buffer layer.
Bibliographical noteFunding Information:
This research was supported by the Nano R&D Program through the Korea Science and Engineering Foundation funded by the Ministry of Education, Science & Technology (2007-02589), and by a Grant from the National Program for Tera-Level Nanodevices of the Korea Ministry of Science and Technology as a 21st Century Frontier Program.
- Phase separation