蓝宝石衬底上单晶InAlGaN外延膜的RF-MBE生长

RF-MBE Growth of InAlGaN Epilayer on Sapphire Substrate

利用射频等离子体辅助分子束外延技术在蓝宝石衬底上外延了晶体质量较好的单晶InAlGaN薄膜.在生长InAlGaN外延层时,获得了外延膜的二维生长.卢瑟福背散射测量结果表明,InAlGaN外延层中In,Al和Ga的组分分别为2%,22%和76%,并且元素的深度分布比较均匀.InAlGaN(0002)三晶X射线衍射摇摆曲线的半高宽为4·8′.通过原子力显微镜观察外延膜表面存在小山丘状的突起和一些小坑,测量得到外延膜表面的均方根粗糙度为2·2nm.利用光电导谱测量InAlGaN的带隙为3·76eV.

A single crystalline InAlGaN film is successfully grown on a sapphire substrate by radio-frequency plasma-excited molecular beam epitaxy. The streaky RHEED pattern observed during growth indicates a layer-by-layer growth mode. Rutherford backscattering spectrometry （RBS） shows that the In, Al, and Ga contents in the InAlGaN film are 2%, 22%, and 76%,respectively. Triple-axis X-ray diffraction shows that the full width at half maximum of the InAlGaN （0002）peak is 4.8′. There are some mountain-like hillocks and pits on the surface of the InAlGaN film. Atomic-force microscopy shows that the RMS of the InAlGaN film is 2.2nm. Photoconductance measurements show that the energy gap of InAlGaN film is 3. 76eV.