화학공학소재연구정보센터
Thin Solid Films, Vol.322, No.1-2, 340-343, 1998
Aging studies on discontinuous silver films in ultrahigh vacuum
The results of aging studies carried out on discontinuous silver films deposited on glass substrates held at room temperature in a vacuum of 2 x 10(-8) Torr are presented in this article. The films were prepared by electron beam deposition at a rate of 0.2 Angstrom/s. Discontinuous silver films show considerable aging for extended period even in a clean ultrahigh vacuum (UHV) obtained using a turbomolecular pump when the oxygen partial pressure is as low as 10(-11) Torr, thus ruling out the possibility of oxidation being responsible for the aging in these films. The coalescence rate values in UHV and in a vacuum of 2 x 10(-6) Torr obtained using an oil diffusion pump are nearly the same. This indicates that the aging of island films is not due to oxidation, A film with an initial resistance of 2 M Ohm/square showed a drastic fall in resistance after about 30 min of aging, This interesting discontinuous-semicontinuous transition observed in a conservative system is a clear evidence for the mobility of islands.