In-situ electrical resistance measurement for determining minimum continuous thickness of Sn films by DC magnetron sputtering

Abstract

Sn thin films were grown by DC magnetron sputtering on a soda-lime glass and Si substrate. The in-situ electrical resistance of the films was measured during the film growth. The minimum continuous thickness of the films was difficult to determine by using the conventional plot of R x d(2) versus d and could only be approximately calculated to be near 20 to 25 nm. On the other hand, a new empirical method using the plot of R x d(3) versus d gave a value of 16 nm for the minimum continuous Sn film thickness. The minimum continuous thickness of Sn films obtained from field-emission scanning electron microscopy and X-ray photoemission spectroscopy analyses was 16 nm. The new empirical method proposed here has the potential to determine the exact minimum continuous thickness of the films. (C) 2012 Elsevier B.V. All rights reserved.