Evolution of surface morphology of vicinal Si(111) surfaces after aluminum deposition

• Published in: Surface science Vol. 418; no. 1; pp. 22 - 31
• Main Authors: Schwennicke, C., Wang, X.-S., Einstein, T.L., Williams, E.D.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 27.11.1998; Amsterdam Elsevier Science; New York, NY
• Subjects: Aluminum; Condensed matter: structure, mechanical and thermal properties; Epitaxy; Exact sciences and technology; LEED; Physics; Scanning Tunneling Microscopy; Silicon; Solid surfaces and solid-solid interfaces; Stepped single crystal surfaces; Surface morphology; Surface structure and topography; Surface thermodynamics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Vicinal single crystal surfaces; Stepped single crystal surfaces; Surface thermodynamics; Vicinal single crystal surfaces; Aluminum; Epitaxy; Scanning Tunneling Microscopy; Surface morphology; Silicon; LEED; Vicinal surface; Terrace; Adsorption structure; Aluminium; Step; Experimental study; Diffusivity; Repulsion interaction; Surface structure
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(98)00658-X

We have studied changes in surface morphology of vicinal Si(111) surfaces with a miscut of 1.3° in the [ 2 ̄ 11] direction after Al deposition at elevated temperatures. The clean surface phase separates into a (111)-oriented phase and a stepped phase. Submonolayer Al deposition at 650°C, the normal preparation temperature of the Al/Si(111)- ( 3 × 3 ) R30° structure, only induces minor changes in the surface morphology. However, after Al deposition at temperatures above the order–disorder phase transition temperature, the step bunches break apart into a uniform array of single height steps with an average step–step separation determined by the macroscopic miscut. From a quantitative analysis of the amount of meandering of steps and the terrace width distribution, we determined the diffusivity of steps and the strength of the repulsive step–step interaction. The repulsive interaction between steps is enhanced by the Al adsorption compared to both the high-temperature (1×1) and (7×7) phases of the clean surface.