Initial stages of GaN/GaAs (100) growth by metalorganic chemical vapor deposition
Authors: Xu, Dapeng; Yang, Hui; Li, J.; Li, S.; Wang, Y.; Zhao, D.; Wu, R.
Source: Journal of Electronic Materials, Volume 29, Number 2, February 2000 , pp. 177-182(6)
Abstract:We have investigated the growth of GaN buffers by metalorganic chemical vapor deposition (MOCVD) on GaAs (100) substrates. Atomic force microscope (AFM) and reflection high-energy electron diffraction (RHEED) were employed to study the dependence of the nucleation on the growth temperature, growth rate, annealing effect, and growth time. A two-step growth sequence must be used to optimize and control the nucleation and the subsequent growth independently. The size and distribution of islands and the thickness of buffer layers have a crucial role on the quality of GaN layers. Based on the experimental results, a model was given to interpret the formation of hexagonal-phase GaN in the cubic-phase GaN layers. Using an optimum buffer layer, the strong near-band emission of cubic GaN with full-width at half maximum (FWHM) value as small as 5.6 nm was observed at room temperature. The background carrier concentration was estimated to be in the range of 1013 ∼ 1014 cm−3.
Document Type: Research Article
Affiliations: Email: email@example.com
Publication date: February 1, 2000