Quantitative evaluation of strain relaxation in annealed sputter-deposited AlN film

• Published in: Journal of crystal growth Vol. 512; pp. 16 - 19
• Main Authors: Tanaka, Shuichi, Shojiki, Kanako, Uesugi, Kenjiro, Hayashi, Yusuke, Miyake, Hideto
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.04.2019; Elsevier BV
• Subjects: A1. Stresses; A1. X-ray diffraction; Aluminum nitride; Annealing; B1. Nitrides; B2. Semiconducting aluminum compounds; B2. Semiconducting III-V materials; B3. Light-emitting diodes; Compressive properties; Dislocation density; Metalorganic chemical vapor deposition; Morphology; Quantitative analysis; Sapphire; Strain relaxation; Substrates; Vapor phases; B1. Nitrides; A1. X-ray diffraction; B3. Light-emitting diodes; B2. Semiconducting aluminum compounds; B2. Semiconducting III-V materials; A1. Stresses
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2019.02.001

•Strain-relaxation of annealed sputtered AlN film on c-plane sapphire was revealed.•Sputtered AlN films before annealing have different strains and tilt mosaics.•The AlN film after annealing consists of a layer that have a compressive strain.•After MOVPE growth, the compressive strain was inherited. The strain relaxation of sputter-deposited AlN (sp-AlN) films on c-plane sapphire substrates before and after face-to-face annealing (FFA) was evaluated. After FFA, the AlN films consisted of a layer with compressive strain and an extremely low dislocation density, which was ascribed to solid-state growth during FFA. In addition, the crystallinity was further improved after the homoepitaxial growth of AlN by metal-organic vapor phase expitaxy (MOVPE). The full widths at half maximum of the X-ray rocking curves of AlN (0 0 0 2) and (1 0 −1 2) for the MOVPE-grown AlN layer on the FFA-sp-AlN film were 15 and 240 arcsec, respectively. The surface morphology of the MOVPE-grown AlN layer on the FFA-sp-AlN film was covered with an atomically flat step-and-terrace structure. The compressive strain of the MOVPE-grown AlN layer was inherited from the underlying FFA-sp-AlN film.