Morphology Analysis of Si Island Arrays on Si(001)

• Published in: Nanoscale research letters Vol. 5; no. 12; pp. 1882 - 1887
• Main Authors: González-González, A, Alonso, M, Navarro, E, Sacedón, J. L, Ruiz, A
• Format: Journal Article
• Language: English
• Published: United States New York : Springer-Verlag 11.08.2010; BioMed Central Ltd; SpringerOpen
• Subjects: Molecular beam epitaxy; Morphology analysis; Scanning probe microscopy; Self-assembly; Silicon nanostructures
• ISSN: 1931-7573; 1556-276X; 1556-276X
• DOI: 10.1186/1556-276X-5-1882

The formation of nanometer-scale islands is an important issue for bottom-up-based schemes in novel electronic, optoelectronic and magnetoelectronic devices technology. In this work, we present a detailed atomic force microscopy analysis of Si island arrays grown by molecular beam epitaxy. Recent reports have shown that self-assembled distributions of fourfold pyramid-like islands develop in 5-nm thick Si layers grown at substrate temperatures of 650 and 750°C on HF-prepared Si(001) substrates. Looking for wielding control and understanding the phenomena involved in this surface nanostructuring, we develop and apply a formalism that allows for processing large area AFM topographic images in a shot, obtaining surface orientation maps with specific information on facets population. The procedure reveals some noticeable features of these Si island arrays, e.g. a clear anisotropy of the in-plane local slope distributions. Total island volume analysis also indicates mass transport from the substrate surface to the 3D islands, a process presumably related to the presence of trenches around some of the pyramids. Results are discussed within the framework of similar island arrays in homoepitaxial and heteroepitaxial semiconductor systems.