A study of semi-insulating GaN grown on AlN buffer/sapphire substrate by metalorganic chemical vapor deposition
Ozturk, M. K.
Journal of Crystal Growth
Yu, H., Ozturk, M. K., Ozcelik, S., & Ozbay, E. (2006). A study of semi-insulating GaN grown on AlN buffer/sapphire substrate by metalorganic chemical vapor deposition. Journal of Crystal growth, 293(2), 273-277.
Please cite this item using this persistent URLhttp://hdl.handle.net/11693/11505
We report the remarkably improved crystal quality of semi-insulating GaN grown by metalorganic chemical vapor deposition on an AlN buffer layer, which is deposited on sapphire substrate. The electrical and structural properties are characterized by dark current-voltage transmission line model and X-ray diffraction measurements. It is found that the crystal quality of the GaN epilayer is strongly related with the growth temperature of the decreased-temperature GaN interlayer. In comparison with the normal GaN grown on sapphire, the crystal quality is remarkably improved along with a semi-insulating electrical character. The high-mobility field effect transistors device based on the semi-insulating GaN shows good pinch off properties. Our electrical measurement results of GaN grown directly on an AlN buffer indicated that the as-grown-undoped GaN is naturally semi-insulating material. The origination of the residual donors in normal GaN grown on sapphire substrate is also discussed. (c) 2006 Elsevier B.V. All rights reserved.