Formation of finger-like step patterns on a Si(111) vicinal face

✍ Scribed by Masahide Sato; Shinji Kondo; Makio Uwaha

• Book ID: 104022096
• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 610 KB
• Volume: 318
• Category: Article
• ISSN: 0022-0248
• DOI: 10.1016/j.jcrysgro.2010.10.093

✦ Synopsis

During deposition of Ga atoms, the structure of a Si(111) vicinal face is transformed from the ffiffiffi 3 p  ffiffiffi 3 p structure to the 6.3  6.3 structure. The transformation occurs preferentially from the lower side of steps. Since the density of Si atoms needed to form the 6.3  6.3 structure is lower than that to form the ffiffiffi 3 p  ffiffiffi 3 p structure, Si atoms are supplied onto the surface during the structural transition. The steps advance by incorporating the extra adatoms, and show a finger-like wandering pattern (H. Hibino, H. Kageshima, M. Uwaha, Surf. Sci. 602 ( 2008) 2421). To study the formation of the finger-like pattern, we carry out Monte Carlo simulations. When atoms are supplied immediately in front of a straight step, the step becomes unstable.

Step wandering occurs and a step shows a finger-like pattern. The characteristic period of the fingers is consistent with the linear stability analysis and proportional to ð b=VÞ 1=2 , where b is the step stiffness and V is the step velocity (deposition rate).