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

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 × 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 × 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.