A
film whose thickness is of the order of a
characteristic scale or smaller. Since a
film may '
look' operationally thin or thick, according to the procedure applied, it is also recommended
that the measurement procedure employed be specified (e.g. ellipsometrically thin
film, optically thin
film, etc.). It is recommended that the physical specification of the
film thickness be used, whenever possible (e.g. thick compared to the electron
mean free path, thin compared to the optical
wavelength, etc.)
Source:
PAC, 1994, 66, 1667
(Thin films including layers: terminology in relation to their preparation and characterization
(IUPAC Recommendations 1994))
on page 1672