Effect of dual buffer layer structure on the epitaxial growth of AlN on sapphire

• Published in: Journal of alloys and compounds 2012-12, Vol.544, p.94-98
• Main Authors: Zhao, D.G., Jiang, D.S., Wu, L.L., Le, L.C., Li, L., Chen, P., Liu, Z.S., Zhu, J.J., Wang, H., Zhang, S.M., Yang, H.
• Format: Article
• Language: English
• Subjects: Alloys; Aluminum nitride; Atomic force microscopy; Buffer layers; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystal growth; Epitaxial growth; Exact sciences and technology; Materials science; Metal organic chemical vapor deposition; Methods of deposition of films and coatings; film growth and epitaxy; Nitride materials; Nucleation; Other semiconductors; Physics; Sapphire; Specific materials; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of film growth; Thin film structure and morphology; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.07.123

► A dual AlN buffer layer structure is proposed to grow AlN films. ► AlN films could be improved obviously by using the dual AlN buffer layer. ► The physical mechanism are discussed. A dual AlN buffer layer structure, including an isolated layer and a nucleation layer, is proposed to improve the growth of AlN films on sapphire substrate by metal organic chemical vapor deposition. This method is aimed to weaken the negative nitridation effect and improve lateral growth condition in the initial growth stage. It is found that suitably increasing the thickness of the nucleation layer is in favor of a better structural quality of the AlN film. An examination of surface morphology by atomic force microscopy suggests that the thicker the dual AlN buffer layer, the rougher the surface, and a higher quality of AlN epilayer is resulted.