MOCVD Growth and Characterization of Epitaxial AlxGa1-xN Films

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2007,（5）
• 页码范围: 1393-1396
• 页数: 4页
• 语种: 英文

摘要

We study the growth of AlxGa1-x N epilayers on (0001) sapphire by low-pressure MOCVD, using a low-temperature A1N buffer. By varying the input now rates of trimethylgallium (TMGa),e 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(1)1) 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 (1011) grains.