Microlithographic projection exposure apparatus with immersion projection lens

摘要

A microlithographic projection exposure apparatus includes an illumination system and a projection lens which images a reticle onto a photosensitive layer. The projection exposure apparatus further includes an immersion arrangement for introducing an immersion liquid into an immersion interspace between a last optical element of the projection lens on the image side and the photosensitive layer. A transmission filter is designed and arranged in the projection lens in such a way that rays which enter the immersion interspace from the last optical element at an angle of incidence alpha are attenuated more strongly the smaller the angle of incidence alpha is. The transmission filter may be arranged e.g. in a pupil plane of the projection lens and may have a transmittance which increases with increasing distance from an optical axis of the projection lens. In this way compensation is provided for angle-dependent absorption in the immersion liquid.