Thickness dependent morphology and resistivity of ultra-thin Al films grown on Si(111) by molecular beam epitaxy

✍ Scribed by Aswal, D. K. ;Joshi, N. ;Debnath, A. K. ;Gupta, S. K. ;Vuillaume, D. ;Yakhmi, J. V.

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 739 KB
• Volume: 203
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200566102

✦ Synopsis

Abstract

The morphology and electrical resistivity of ultrathin Al metal films grown on (111) Si substrates using molecular‐beam epitaxy have been investigated. For thickness <60 nm, the film morphology consists of a two‐dimensional network of Al islands, which grows via Volmer–Weber mechanism. The coalescence of islands is found to begin at a thickness of 60 nm. The room‐temperature value of resistivity, contrary to the theoretical predictions of existing models, is found to increase monotonically with thickness. Also the temperature dependence of these films exhibited a metal‐to‐insulator transition at 110 K. The anomalous temperature dependences of resistivity have been explained using a two‐dimensional variable range hopping conduction (2d‐VRH) mechanism. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)