A method, called the silicon plate method, has been developed using a small
sampling device with a clean simple process, in order to directly evaluate
organic contamination on a silicon wafer surface that came from the cleanr
oom air. Using this method, the concentration of bis(2-ethylhexyl)phthalate
on the silicon wafer surface is experimentally shown, for the first time,
to reach a steady state which has a relationship with its concentration in
the cleanroom air. The experimental results are consistent with those theor
etically predicted using the model of multicomponent organic species adsorp
tion-induced contamination; therefore, the silicon plate method is conclude
d to be effective for evaluating the time-dependent behavior of organic spe
cies on the silicon wafer surface. (C) 2001 The Electrochemical Society.