In this study, organic compounds in cleanroom air and on silicon (Si) wafer surface were investigated by using gas chromatograph-mass spectroscopy (GC-MS) and thermal desorption-atmospheric pressure ionization MS (TD-APIMS). The adsorption mechanisms of organic compounds on Si wafer surface were considered. We prepared two different types of Si wafers; one was with hydrogen terminate and another one was with native oxygen. These wafers were exposed in the organic gases exposure system under a control of moisture, organic gases concentration and exposure time. The results of this study are as follows; (1) ethylene, the non polar substance, was detected with higher concentrations from Si wafer with hydrogen terminate than that with native oxygen, (2) dioctyl phthalate, the polar substance, was detected with higher concentrations from Si wafer with native oxygen than that with hydrogen terminate, and (3) moisture had influences on the adsorption on Si wafer.
