Polarity effects of substrate surface in homoepitaxial ZnO film growth

• Published in: Journal of crystal growth Vol. 219; no. 4; pp. 361 - 367
• Main Authors: Zhu, Shen, Su, C.-H, Lehoczky, S.L, Harris, M.T, Callahan, M.J, McCarty, P, George, M.A
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-11-2000; Elsevier
• Subjects: AFM; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Epitaxial growth; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Structure; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; ZnO crystal; ZnO crystal; AFM; Epitaxial growth; Structure; Temperature dependence; Homoepitaxy; Atomic force microscopy; Inorganic compounds; Epitaxial layers; Transition element compounds; Surfaces; Crystal growth from vapors; XRD; Experimental study; Substrates; Surface structure; Thin films; Magnetrons; Surface termination; Zinc oxides; Morphology; Polarity; Thermal annealing; Radiofrequency sputtering
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(00)00726-0

Epitaxial ZnO films were grown on two polar surfaces (O-surface and Zn-surface) of (0
0
0
1) ZnO single-crystal substrates using off-axis magnetron sputtering deposition. It was found that the two polar ZnO surfaces have different surface structure and morphology, which strongly influence epitaxial film growth. An interesting result shows that high-temperature annealing of ZnO single crystals will improve the surface structure on the O-terminated surface rather than the opposite surface. The morphology and structure of homoepitaxial films grown on the ZnO substrates were different from heteroepitaxial films grown on the Al
2O
3. The measurements of low-angle incident X-ray diffraction and atomic force microscopy of ZnO films indicate that the O-terminated surface is better for ZnO epitaxial film growth.