IN-SITU MONITORING OF FILM DEPOSITION WITH AN ELLIPSOMETER BASED ON A4-DETECTOR PHOTOPOLARIMETER

Ellipsometry is a sensitive and noninvasive technique for the characte rization of thin films. A recently developed ellipsometer, based on th e four-detector photopolarimeter, was arranged outside a UHV chemical vapor deposition chamber for the in situ monitoring of film growth pro cesses. The instrument showed a sensitivity in the submonolayer range when used to follow the growth of germanium thin films deposited on si licon substrates. As the main instrument drawback is represented by th e need to have precise alignment, an effective positioning procedure w as developed to obtain a positioning error smaller than 0.1 degrees. ( C) 1996 Optical Society of America