Optimization of the surface morphologies and electron mobilities in GaN grown by plasma-assisted molecular beam epitaxy
- 24 October 2000
- journal article
- research article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 77 (18) , 2885-2887
- https://doi.org/10.1063/1.1322370
Abstract
The morphology and electrical properties of homoepitaxial GaN layers grown by molecular beam epitaxy at 720 °C were investigated as a function of Ga/N ratio. GaN films grown with low Ga/N ratios (N-stable regime) are semi-insulating and have heavily pitted morphologies. GaN films grown with higher Ga/N ratios (intermediate regime) have fewer pits with areas of atomically flat surface. The room-temperature electron mobilities in samples grown in the intermediate regime are greater than 800 cm2/V s and increase with Ga/N ratio. At the highest Ga/N ratios (Ga-droplet regime), Ga droplets formed on the surface during growth. Although the surface morphology is free of pits and atomically flat for films grown within the Ga-droplet regime, the mobility decreases significantly compared to films grown in the intermediate regime. Room-temperature electron mobilities as high as 1191 cm2/V s were measured in a GaN film grown with the highest Ga/N ratio within the intermediate regime.Keywords
This publication has 11 references indexed in Scilit:
- Control of GaN surface morphologies using plasma-assisted molecular beam epitaxyJournal of Applied Physics, 2000
- Dislocation Scattering in GaNPhysical Review Letters, 1999
- Effect of ammonia flow rate on impurity incorporation and material properties of Si-doped GaN epitaxial films grown by reactive molecular beam epitaxyJournal of Applied Physics, 1998
- The role of dislocation scattering in n-type GaN filmsApplied Physics Letters, 1998
- Deep centers in n-GaN grown by reactive molecular beam epitaxyApplied Physics Letters, 1998
- Scattering of electrons at threading dislocations in GaNJournal of Applied Physics, 1998
- Homoepitaxial growth of GaN under Ga-stable and N-stable conditions by plasma-assisted molecular beam epitaxyJournal of Applied Physics, 1997
- Defect Donor and Acceptor in GaNPhysical Review Letters, 1997
- A comparative study of GaN epilayers grown on sapphire and SiC substrates by plasma-assisted molecular-beam epitaxyApplied Physics Letters, 1993
- In situ monitoring and Hall measurements of GaN grown with GaN buffer layersJournal of Applied Physics, 1992