Dynamics of spontaneous roughening on the GaAs(0 0 1)-(2×4) surface

• Published in: Journal of crystal growth 2003-04, Vol.251 (1), p.35-39
• Main Authors: Ding, Z., Bullock, D.W., Oliver, W.F., Thibado, P.M., LaBella, V.P.
• Format: Article
• Language: English
• Subjects: A1. Defects; A1. Diffusion; A1. Morphological stability; A1. Roughening; A1. Scanning tunneling microscopy; A1. Surfaces; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electron, ion, and scanning probe microscopy; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Scanning probe microscopy: scanning tunneling, atomic force, scanning optical, magnetic force, etc; Solid surfaces and solid-solid interfaces; Structure of solids and liquids; crystallography; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of film growth
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(02)02272-8

The dynamics of a random distribution of spontaneously formed 2D GaAs islands are studied using scanning tunneling microscopy. The equilibrium concentration of islands is easily tuned from 0% to 50% coverage by only changing the As 4 overpressure. Images taken during the early stages of island formation reveal the roughening transition primarily occurs through an intermediate pit formation phase. Interestingly, pit formation in the middle of an otherwise pristine terrace is overwhelmingly preferred to atom detachment from the edges of the terraces.