摘要 |
The filter comprises alternating layers of relatively high and relatively low refractive index media. The layers are formed as a coating on an optical component in the projection lens system of a lithographic projection apparatus. The filter transmits radiation at a wavelength of 157 nm for exposing an image of a mask pattern on a resist-coated substrate whilst attenuating radiation resulting from fluorescence in optical components of the lithographic projection apparatus, caused by the imaging radiation, and which if not attenuated would reduce the contrast of the image exposed in the resist. <IMAGE> <IMAGE> |