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DENNIS CAPITANIO, Pall Corporation, Port Washington, NY, USA

ABSTRACT

The trends toward narrower linewidths in the manufacture of integrated circuits has put an ever increasing
burden on contamination control in every aspect of semiconductor fabrication. Point-of-use (POU) filtration of
photoresists has been used to control particle contamination on the wafer surface during coating operations.
The need for tighter filtration has led to the introduction of 0.05 μm as well as the traditional 0.10 μm membranes
to control the contamination during the dispense of photoresists. With the introduction of tighter membranes for
use in photoresist filtration, the end-user may have concerns that the photoresist may suffer some deleterious effects
by undergoing filtration.

This study centers on the use of 0.05 μm and 0.10 μm Pall Falcon® filters in dispensing Microposit* S1813* photoresist for reducing surface defects on the wafer surface. The results of gel permeation chromatography (GPC) on filtered and unfiltered photoresist showed no effect on the molecular weight of the photosensitive components. Viscosity and coating thickness results indicated no loss in solids that would have an effect on the viscosity and in turn the coating thickness on the wafer surface. Exposure demonstrated a retention of photospeed indicating no damaging effects on resin or photosensitive components.

The applications of filtration to photoresist dispensing are demonstrated as a positive step to lowering contamination on the wafer surface without deleterious effects on the performance of the photoresist.