Wang Wenliang, Wang Haiyan, Yang Weijia, Zhu Yunnong, Li Guoqiang
State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.
Engineering Research Center on Solid-State Lighting and its Informationisation of Guangdong Province, South China University of Technology, Guangzhou 510640, China.
Sci Rep. 2016 Apr 22;6:24448. doi: 10.1038/srep24448.
High-quality GaN epitaxial films have been grown on Si substrates with Al buffer layer by the combination of molecular beam epitaxy (MBE) and pulsed laser deposition (PLD) technologies. MBE is used to grow Al buffer layer at first, and then PLD is deployed to grow GaN epitaxial films on the Al buffer layer. The surface morphology, crystalline quality, and interfacial property of as-grown GaN epitaxial films on Si substrates are studied systematically. The as-grown ~300 nm-thick GaN epitaxial films grown at 850 °C with ~30 nm-thick Al buffer layer on Si substrates show high crystalline quality with the full-width at half-maximum (FWHM) for GaN(0002) and GaN(102) X-ray rocking curves of 0.45° and 0.61°, respectively; very flat GaN surface with the root-mean-square surface roughness of 2.5 nm; as well as the sharp and abrupt GaN/AlGaN/Al/Si hetero-interfaces. Furthermore, the corresponding growth mechanism of GaN epitaxial films grown on Si substrates with Al buffer layer by the combination of MBE and PLD is hence studied in depth. This work provides a novel and simple approach for the epitaxial growth of high-quality GaN epitaxial films on Si substrates.
通过分子束外延（MBE）和脉冲激光沉积（PLD）技术相结合，在带有铝缓冲层的硅衬底上生长出了高质量的氮化镓外延膜。首先使用MBE生长铝缓冲层，然后利用PLD在铝缓冲层上生长氮化镓外延膜。系统地研究了在硅衬底上生长的氮化镓外延膜的表面形貌、晶体质量和界面特性。在硅衬底上，于850°C下生长的具有约30nm厚铝缓冲层的约300nm厚氮化镓外延膜，其氮化镓（0002）和氮化镓（102）X射线摇摆曲线的半高宽分别为0.45°和0.61°，显示出高晶体质量；氮化镓表面非常平整，均方根表面粗糙度为2.5nm；以及氮化镓/铝镓氮/铝/硅异质界面清晰且陡峭。此外，还深入研究了通过MBE和PLD相结合在带有铝缓冲层的硅衬底上生长氮化镓外延膜的相应生长机制。这项工作为在硅衬底上外延生长高质量氮化镓外延膜提供了一种新颖且简单的方法。
