Autocollimation-type ellipsometer for monitoring film growth through a single window

Three autocollimation-type ellipsometers (ACE) are proposed for in situ study or monitoring of film growth through a single window of a vacuum chamber. An example of the monitoring is given; the growth process of a Corning 7059 glass film is monitored during rf sputtering using one of the ACE that is able to monitor directly the thickness of a transparent film.