Determination of Adsorption Layers on Silicon Sorption Artifacts using the Gravimetric Method

The adsorption layers on the surface of silicon artifacts were determined experimentally as a function of relative air humidity in the range of 0.07 < h < 0.73 using the gravimetric method. 1 kg silicon sorption artifacts were fabricated with the same surface finish and material properties, but they had a very different surface area of 507.8 cm². In this experiment, an ultra-precision mass comparator and special humidity control unit were used. We found that the sorption behavior of the silicon surface was type II by BET classification with the parameters μ _m  = 0.017 μg/cm², and c _B  = 9.3 from the adsorption isotherm of water vapor on the surface of silicon with R _z  < 26.6 nm. The coefficient of water vapor adsorption in moist air was estimated as δμ/δh = 65.3 ng cm^?2 in a limited humidity range of 0.3 < h < 0.6.