Plasma-Assisted MOCVD Growth of Non-Polar GaN and AlGaN on Si(111) Substrates Utilizing GaN-AlN Buffer Layer

Coatings

Pepen Arifin¹  Sugianto²  Heri Sutanto³  Agus Subagio³ 

[1] Department of Physics, Physics of Electronic Materials Research Division, Faculty of Mathematics and Natural Sciences, Institute of Technology Bandung, Jl. Ganesha 10, Bandung 40132, Indonesia;Department of Physics, Universitas Negeri Semarang, Sekaran, Gunungpati, Semarang 50229, Indonesia;Department of Physics, University of Diponegoro, Jl. Prof. Soedharto, SH, Tembalang, Semarang 50275, Indonesia;

关键词: non-polar GaN;    AlGaN;    PA-MOCVD;    buffer layer;    Si(111);    m-plane GaN;   

DOI  :  10.3390/coatings12010094

来源: DOAJ

【 摘 要 】

We report the growth of non-polar GaN and AlGaN films on Si(111) substrates by plasma-assisted metal-organic chemical vapor deposition (PA-MOCVD). Low-temperature growth of GaN or AlN was used as a buffer layer to overcome the lattice mismatch and thermal expansion coefficient between GaN and Si(111) and GaN’s poor wetting on Si(111). As grown, the buffer layer is amorphous, and it crystalizes during annealing to the growth temperature and then serves as a template for the growth of GaN or AlGaN. We used scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) characterization to investigate the influence of the buffer layer on crystal structure, orientation, and the morphology of GaN. We found that the GaN buffer layer is superior to the AlN buffer layer. The thickness of the GaN buffer layer played a critical role in the crystal quality and plane orientation and in reducing the cracks during the growth of GaN/Si(111) layers. The optimum GaN buffer layer thickness is around 50 nm, and by using the optimized GaN buffer layer, we investigated the growth of AlGaN with varying Al compositions. The morphology of the AlGaN films is flat and homogenous, with less than 1 nm surface roughness, and has preferred orientation in a-axis.

【 授权许可】

Unknown