Analysis of Organic Contaminants in Cleanroom Air and on Silicon Wafer Surface

摘要

Concentrations of organic contaminants (hereafter abbreviated as ORCs)in cleanroom air were measured regularly since operations in a new cleanroom were started. Concentrations of ORCs in cleanroom air gradually decreased and attained steady state values after six months. The removal efficiency of a chemical filter for total ORCs was significantly reduced with time, however the efficiencies for di(2-ethylhexyl)phthalate (DOP), di(isobutyl) phthalate and low molecar weight cyclosiloxanes (LMCSs) remained at a sufficiently high value for three years. The sticking probabilities of DOP and Trichloroethylphosphate onto Si surface were estimated to be 1X10~(-2) and 5X10~(-3) from the concentrations of ORCs in the air and the masses of ORCs deposited on Si wafers.