کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1793499 | 1023677 | 2010 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Linear dependency of Al-mole fraction with group-III precursor flows in AlxGa1−xN (0≤x≤1) deposition by LP OMVPE Linear dependency of Al-mole fraction with group-III precursor flows in AlxGa1−xN (0≤x≤1) deposition by LP OMVPE](/preview/png/1793499.png)
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.
Journal: Journal of Crystal Growth - Volume 312, Issue 8, 1 April 2010, Pages 1321–1324