James R. Przybyla

Effect of g-line filter transmission characteristics on dose matching between monochromatic exposure tools in a production environment

To maintain critical dimension control in a production environment, it is essential that all wafer steppers have their effective doses matched. Because high pressure Mercury illumination sources actually have a bandwidth of 10 nm and typical resist absorbance curves are dropping steeply around the 436 nm region, differences between G-line filters can cause exposure shifts between steppers. Functional exposure differences on dose to clear wafers of 9% are explained by combining integrator and G-line filter spectrophotometer tests on ten .54 NA wafer steppers.