Molecular Beam Epitaxy of Nitrides: Theoretical Modeling and Process Simulation
Abstract
A rate equation approach is proposed based on physically sound surface processes to investigate the molecular beam epitaxy growth and doping of 111-N using ammonia and ECR plasma source. A surface riding layer of Ga/In/Mg and ammonia or N plasma species are included in the model. The surface riding species are allowed to undergo several physical and chemical processes. In the case of ammonia, the simulated Ga incorporation rate as a function of ammonia pressure and substrate temperature are in excellent agreement with the experimental data. Ga incorporation increases with increasing ammonia overpressure. Simulated Ga desorption parameter versus time data is also in good qualitative agreement with the experimental data. In the case of ECR plasma, electron concentration obtained from bulk vacancy concentrations of Ga and N decreases linearly with ECR power unlike the experimental observation of exponential decrease. In InGaN growth, results of In incorporation obtained from simulations and experiments are in excellent agreement for various growth conditions. In segregation is found to be negligible below 580 deg C. Above 640 deg C, the segregation dominates the kinetics. This temperature dependence is found to be independent of the fluxes. In MgGaN growth, simulations were carried for various growth temperatures in the range of 600-750 deg C. with constant flux rates of Mg, Ga and N. For the given flux rates, it is found that Mg segregates the surface with the increase in temperature. Above 750 deg C a dopant depleted zone is formed below the surface layer. Results obtained from simulations are in excellent agreement with the experimental data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2003
- Accession Number
- ADA418076
Entities
People
- Rama Venkat
Organizations
- University of Nevada, Las Vegas