Effects of thermal annealing on the morphology of the AlxGa(1−x)N films

✍ Scribed by S. Çörekçi; Z. Tekeli; M. Çakmak; S. Özçelik; Y. Dinç; O. Zeybek; E. Özbay

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 637 KB
• Volume: 12
• Category: Article
• ISSN: 1369-8001
• DOI: 10.1016/j.mssp.2009.12.004

✦ Synopsis

Effects of thermal annealing on the morphology of the Al x Ga (1 À x) N films with two different high Al-contents (x =0.43 and 0.52) have been investigated by atomic force microscopy (AFM). The annealing treatments were performed in a nitrogen (N 2 ) gas ambient as short-time (4 min) and long-time (30 min). Firstly, the films were annealed as short-time in the range of 800-950 1C in steps of 50-100 1C. The surface root-meansquare (rms) roughness of the films reduced with increasing temperature at short-time annealing (up to 900 1C), while their surface morphologies were not changed. At the same time, the degradation appeared on the surface of the film with lower Al-content after 950 1C. Secondly, the Al 0.43 Ga 0.57 N film was annealed as long-time in the range of 1000-1200 1C in steps of 50 1C. The surface morphology and rms roughness of the film with increasing temperature up to 1150 1C did not significantly change. Above those temperatures, the surface morphology changed from step-flow to grain-like and the rms roughness significantly increased.