2010 article

Linear dependency of Al-mole fraction with group-III precursor flows in AlxGa1-xN (0 <= x <= 1) deposition by LP OMVPE

Rice, A., Collazo, R., Tweedie, J., Xie, J., Mita, S., & Sitar, Z. (2010, April 1). JOURNAL OF CRYSTAL GROWTH, Vol. 312, pp. 1321–1324.

By: A. Rice n, R. Collazo n, J. Tweedie n, J. Xie*, S. Mita* & Z. Sitar n

co-author countries: United States of America 🇺🇸
author keywords: Low-pressure metalorganic vapor phase epitaxy; Organometallic vapor phase epitaxy; Nitrides; Semiconducting III-V materials; Semiconducting ternary compounds
Source: Web Of Science
Added: August 6, 2018

AlxGa1−xN/GaN heterostructures (0≤x≤1) were deposited on (0 0 0 1)-sapphire by low-pressure (20 Torr) organometallic vapor phase epitaxy utilizing a range of group-III precursor and NH3 flow rates and a deposition temperature of 1050 °C. The Al-mole fraction of AlxGa1−xN layers was controlled by variations in the molar flows of triethylgallium (fTEG) and trimethylaluminum (fTMA). Characterization by X-ray diffraction confirmed that increasing the fTMA/fTEG ratio during deposition resulted in increased Al-mole fraction of AlxGa1−xN layers. A linear relationship between the experimental Al-mole fraction of AlxGa1−xN layers and the group-III precursor flows was obtained if a correction factor γ was introduced such that x=γfTMA/(γfTMA+fTEG). This correction factor was found to be independent of group-III precursor flows but dependent on NH3 partial pressure. The value of γ for these experiments decreased from 1.4 to 1.0 when the NH3 partial pressure was increased from 0.8 to 16.0 Torr during AlxGa1−xN deposition. The growth rate of AlxGa1−xN layers was found to be a linear combination of the independent AlN and GaN growth rates when equivalent fTMA and fTEG were utilized under the same deposition conditions.