Study of Outgassing from the ArF CA Resist During ArF (193 nm) Exposure

Abstract

In recent years, we have seen growing numbers of reports on problems associated with outgas generated from resists during ArF exposure, including contaminating of the exposure equipment lens. Scanner manufacturers have apparently begun taking countermeasures—for example, establishing criteria for outgas generated by resists during exposure. In the near future, resist manufacturers will likely be required to attach documents regarding outgassing to their products at the time of shipment. In our earlier studies, we tried to establish methods for evaluating outgassing from KrF resists during KrF (248 nm) exposure. This paper examines an approach to evaluating outgassing from ArF chemically-amplified resists during ArF exposure, with a special focus on sulfate ions (SO₄ ^2－) derived from PAG, based on the outgas analytical techniques that we have built up to date. We used ion chromatography (IC) as the method of analysis.