Mass density determination of thin organosilicon films by X-ray reflectometry

The mass density of thin organosilicon films deposited by chemical vapour d eposition on silicon (0 0 1) surfaces has been determined by X-ray reflecto metry. This method does not give a unique mass density value, but instead a bandwidth of possible values and compositions that an compatible with the experimental data if the layer thickness is not larger than about 350 nm. F or thicker films thickness values obtained from ellipsometry data are used. The possible composition ranges are compared with data obtained by X-ray p hoto electron spectroscopy. (C) 2001 Elsevier Science B.V. All rights reser ved.