thin film

Also contains definition of: thick film
https://doi.org/10.1351/goldbook.T06345
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 [Terms] [Paper]