Thin silicon nitride films (less than 20 nm) deposited on (100) silicon substrates via low pressure chemical vapor deposition (LPCVD) at three temperatures (730, 760, and 825degreesC) were analyzed by spectroscopic ellipsometry (SE), attenuated total reflection (ATR), and other tools. Films appeared to have similar optical bandgaps (similar to5 eV), and the values decreased slightly with the higher deposition temperature. Second ionic mass spectroscopy results showed that a similar amount of oxygen exists in the interface between silicon and silicon nitride. ATR spectra showed no sign of Si-H bonds and decreasing N-H bonds at higher deposition temperature in the thin films. The electrical properties of the films are also discussed. (C) 2003 The Electrochemical Society.