MOCVD Growth and Characterization of Epitaxial AlxGa1-x N Films
LI Liang1, ZHANG Rong1, XIE Zi-Li1, ZHANG Yu 1, 2, XIU Xiang-Qian1, LIU Bin1, CHEN Lin1, YU Hui-Qiang1, HAN Ping1, GONG Hai-Mei3, ZHENG You-Dou1
1Key Laboratory of Advanced Photonic and Electronic Materials, Department of Physics, Nanjing University, Nanjing 2100932Department of Physics, School of Applied Science, University of Science and Technology Beijing, Beijing 1000833Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083
MOCVD Growth and Characterization of Epitaxial AlxGa1-x N Films
1Key Laboratory of Advanced Photonic and Electronic Materials, Department of Physics, Nanjing University, Nanjing 2100932Department of Physics, School of Applied Science, University of Science and Technology Beijing, Beijing 1000833Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083
摘要We study the growth of AlxGa1-x N epilayers on (0001) sapphire by low-pressure MOCVD, using a low-temperature AlN buffer. By varying the input flow rates of trimethylgallium (TMGa), we obtain crack-free AlGaN films in the whole range of composition. A linear relationship between gas and solid Al content is observed. The structural properties of the layers (x = 0-1) are investigated by x-ray diffraction, atomic force microscopy (AFM) and scanning electron microscopy (SEM). It is found that a two-direction growth appears along the c-axis and the (10\11) directions for x≥0.45. From the results of Raman spectroscopy, we suggest that the compressive stain and the lack of mobility of Al adatoms can induce the formation of (10\11) grains.
Abstract：We study the growth of AlxGa1-x N epilayers on (0001) sapphire by low-pressure MOCVD, using a low-temperature AlN buffer. By varying the input flow rates of trimethylgallium (TMGa), we obtain crack-free AlGaN films in the whole range of composition. A linear relationship between gas and solid Al content is observed. The structural properties of the layers (x = 0-1) are investigated by x-ray diffraction, atomic force microscopy (AFM) and scanning electron microscopy (SEM). It is found that a two-direction growth appears along the c-axis and the (10\11) directions for x≥0.45. From the results of Raman spectroscopy, we suggest that the compressive stain and the lack of mobility of Al adatoms can induce the formation of (10\11) grains.
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2007, Vol. 24 
