Properties of GaN on different polarity buffer layers by hydride vapour phase epitaxy

• 来源期刊: 中国物理（英文版）
• 关键词: GaN HVPE MBE polarity
• 年，卷（期）: 2007,（7）
• 页码范围: 2082-2086
• 页数: 5页
• 语种: 英文

摘要

This paper reports on N-, mixed-, and Ga-polarity buffer layers are grown by molecular beam epitaxy (MBE) on sapphire (0001) substrates, with the GaN thicker films grown on the buffer layer with different polarity by hydride vapour epitaxy technique (HVPE). The surface morphology, structural and optical properties of these HVPF-GaN epilayers are characterized by wet chemical etching, scanning electron microscope, x-ray diffraction, and photoluminescence spectrum respectively. It finds that the N-polarity film is unstable against the higher growth temperature and wet chemical etching,while that of GaN polarity one is stable. The results indicate that the crystalline quality of HVPE-GaN epilayers depends on the polarity of buffer layers.