N-Limited versus Ga-Limited Growth on GaN(0001(bar)) by MBE using NH3

Surface Review and Letters 5(3&4), 913 (1998).

GaN was grown on GaN(0001(bar)) by MBE using NH3 and a Ga Knudsen cell. The growth kinetics on samples of this polarity were investigated with desorption mass spectroscopy (DMS) and reflection high-energy electron diffraction (RHEED). Both techniques were used to observe and control surface termination, Ga condensation, and surface temperature. GaN growth and decomposition rates were measured by DMS. Two stable surface terminations were found to exist -- N-terminated and Ga-terminated GaN(0001(bar)). The N-terminated surface also contained hydrogen which desorbed during growth at a rate proportional to the growth rate. Low temperature reconstructions were only observed by adding weakly adsorbed Ga on top of the Ga terminated surface. During growth two distinct growth regimes were identified, growth under excess NH3 and growth under excess Ga. Growth is limited in both regimes by GaN decomposition at high temperatures with an activation energy of 3.4 eV. Growth in the excess Ga regime ceased below the Ga condensation temperature. Under conditions of excess NH3, strong but damped oscillations in the specular RHEED intensity were observed on smooth surfaces. Contrary to previous suggestions, the period of these oscillations did not correspond exactly to integral layer deposition and were not characteristic of a narrow growth front. Further, the growth mode changed from island nucleation to step flow with an activation energy of 1.2 eV. Under conditions of excess Ga, surfaces were smoother, but RHEED intensity oscillations were not observed, indicating a step-flow growth mode. In this latter regime RHEED measurements were very sensitive to termination changes on the GaN(0001(bar)) surface, and the growth rate was found to decrease linearly with increasing Ga flux. This reduction is explained by a model in which weakly adsorbed Ga blocks reaction at strongly bound Ga. A map is presented to provide a framework to categorize the overall growth.

This item cites the following items in the database:

1. Emerging GaN Based Devices
2. Progress and Prospects for GaN and the III-V Nitride Semiconductors
3. Deposition and Characterization of Diamond, Silicon Carbide and Gallium Nitride Thin Films
4. GaN, AlN, and InN: A review
5. Molecular beam epitaxy of GaN(0001) utilizing NH₃ and/or NH⁺_x ions: Growth kinetics and defect structure MBE of GaN(0001) utilizing NH₃ and/or NH⁺_x ions
6. Gallium Incorporation Kinetics During GSMBE of GaN
7. Structural Characterization of Bulk GaN crystals Grown Under High Hydrostatic Pressure
8. In Situ Control of GaN Growth by Molecular Beam Epitaxy
9. MBE Growth of (In)GaN for LED Applications
10. Growth Rate Reduction of GaN Due to Ga Surface Accumulation
11. The effect of atomic hydrogen on the growth of gallium nitride by molecular beam epitaxy
12. Investigation of GaN deposition on Si, Al₂0₃, and GaAs using in situ mass spectroscopy of recoiled ions and reflection high-energy electron diffraction
13. Surface lifetimes of Ga and growth behavior on GaN(0001)surfaces during molecular beam epitaxy
14. High quality GaN growth at high growth rates by gas-source molecular beam epitaxy
15. In Situ Monitoring of Reflection High Energy Electron Diffraction Oscillation During the Growth of Gallium Nitride Films by Gas Source Molecular Beam Epitaxy
16. Activation energy for the sublimation of gallium nitride
17. Heteroepitaxial wurtzite and zinc-blende structure GaN grown by reactive-ion molecular-beam epitaxy: Growth kinetics, microstructure, and properties
18. Growth kinetics and catalytic effects in the vapor phase epitaxy of gallium nitride
19. In situ monitoring of GaN growth using interference effects
20. Gallium Incorporation Kinetics During GSMBE of GaN
21. Thermodynamic and kinetic processes involved in the growth of epitaxial GaN thin films
22. Reconstructions of the GaN(0001(bar)) Surface
23. Reflection mass spectrometry of As incorporation during GaAs molecular beam epitaxy
24. Vapor Pressure Constants of Elements
25. The influence of inversion domains on surface morphology in GaN grown by molecular beam epitaxy

This item is cited by the following items in the database:

1. The growth rate evolution versus substrate temperature and V/III ratio during GaN MBE using ammonia
2. Review of polarity determination and control of GaN

Contributed by R. Held from pc23.ece.umn.edu. on Thursday, September 17, 1998 5:40:49 PM

last updated Thursday, April 28, 2005 1:50:07 PM.
© 1998 The Materials Research Society