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KAY LEDERER, STEFFEN HORNIG & RALF SCHUSTER, Infineon Technologies SC300, Dresden, Germany

ABSTRACT
In this paper, we discuss implications currently relevant to 300mm lithography resist processing. The larger wafer size has highlighted a range of resist process issues that were not encountered at the smaller wafer sizes. In particular, resist thickness fluctuations around the edge area of a silicon wafer typically occur if high spin speeds are applied during the coating process. 300mm coating processes are particularly prone to the occurrence of such spin marks as the operating range of applicable spin speeds is lower in comparison to processes applied to smaller sized wafers. We show in our example how such local resist thickness fluctuations impact the product yield. The paper will also show how we investigated a novel resist development process based on a new developer dispense nozzle to combat this problem. Finally we discuss a special type of micromasking defect that was found to be particularly relevant to 300mm lithography layers. This “doughnuttype” defect detracts the yield of the semiconductor product. We discovered that the occurrence of the defect directly depends on the matching of the airflows entering and leaving the 300mm coater cup. The mechanism of formation involves the presence of a photoresist-solvent aerosol.