Mass density determination of thin organosilicon ®lms by X-ray re¯ectometry

The mass density of thin organosilicon ®lms deposited by chemical vapour deposition on silicon (0 0 1) surfaces has been determined by X-ray re¯ectometry. This method does not give a unique mass density value, but instead a bandwidth of possible values and compositions that are compatible with the experimental data if the layer thickness is not larger than about 350 nm. For thicker ®lms thickness values obtained from ellipsometry data are used. The possible composition ranges are compared with data obtained by X-ray photo electron spectroscopy. # 2001 Elsevier Science B.V. All rights reserved.