Abstract
In order to precisely control the microelectronics manufacturing processes, it is essential to reduce or remove the moisture in the gases, which is desorbed from the surface of gas supply system. The equilibrium concentration of adsorbed moisture and its heat of adsorption on variously finished stainless steel surfaces have been introduced in this paper, and the removal characteristics of adsorbed moisture have been investigated using Atmospheric Pressure Ionization Mass Spectrometry (APIMS). The multi-layers of the adsorbed moisture on electro-polished surface of 316L stainless steel could be removed with only continuous purging at room temperature. Also, the effect of batch purging for adsorbed moisture on the surface has been described. However, since it has been speculated that the adsorbed moisture with about 1015 molecules/cm2 remains on the surface only with room temperature purging, a careful operation of gas supply system is needed to use high purity gas without desorbed moisture from the surface, after seal-off the gas in gas supply system.
