Abstract: An optical integrator for an illumination device of a microlithographic projection exposure system has a rod made of a material transparent for ultraviolet light and with a rectangular cross-section. A rod arrangement with, for example, seven small rods made of the same material is arranged before the entrance surface of the rod. The aspect ratio between width and height of the small rods is the inverse of the aspect ratio between width and height of the rod. The rod arrangement, or some analogous structure, surface or treatment substituted therefor, serves to compensate the direction-dependent total reflection losses of the rod.

Abstract: A lithographic projection apparatus is provided with a sensor for detecting luminescence radiation produced in the projection lens system by the passage of the projection beam. The luminescence radiation is indicative of the dose delivered to the substrate, and can be detected close to the substrate to avoid errors due to transmission variations in the optical path from the radiation source to the substrate.

Abstract: A microphone or other acoustic sensor is used to detect sound or other vibrations caused by the passage of pulses of radiation of a projection beam. The measured vibrations may be used to determine the intensity of the projection beam or the presence of contaminants. The vibrations are caused by absorption of the beam pulses in an absorptive gas or by objects, e.g. the substrate or mirrors in the projection lens, on which the projection beam is incident.

Abstract: A lithographic projection system has an optical element provided in the illumination system for changing an elliptically symmetric intensity anomaly of the projection beam in a pupil of the projection apparatus, the optical element being rotated about the optical axis of the projection apparatus such that the change in intensity anomaly introduced by it counteracts an elliptically symmetric intensity anomaly present in the projection beam or introduced by another optical element traversed by the projection beam.

Abstract: In a lithographic projection system using exposure radiation of 157 nm, compositions of gas, e.g. levels of oxygen and water vapor, are measured in regions traversed by the projection beam. The attenuation caused by said gases is predicted and the dose of radiation accumulated during an exposure, the uniformity and angular distribution of radiation energy delivered by said projection beam to a substrate during an exposure is controlled accordingly. The control may comprise a controlled supply of O2 to a volume traversed by the projection beam so as to effect a controlled attenuation of the projection beam. The O2 distribution may be non-uniform, e.g. to selectively filter spatially separated diffraction orders or to eliminate non-uniformity's in the projection beam.

Abstract: 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.