Abstract: A method for improving the uniformity of a lithographic process. In one aspect, the probability density function of a first and second lithographic apparatus are matched by providing a continuous z-motion to a stage in the first lithographic apparatus during substrate exposure. Preferably, the z-motion is characterized by a normally distributed function, wherein the effective probability density function of the first apparatus is substantially similar to the probability density function of the second apparatus.

Abstract: The present invention provides a lithographic apparatus comprising an illumination system for providing a projection beam of radiation. The illumination system comprises at least one movable optical element (7), such that a projection beam of radiation (4) can be shifted around a central position. This ensures that inhomogeneities in the intensity distribution in the projection beam (4) will be smeared out, which in turn provides an improved homogeneity of the exposure of a surface to be illuminated by the system, such as a wafer or other substrate. The optical element (7) may comprise a motor movable mirror, prism, filter, lens, axicon, diffuser, diffractive optical array, optical integrator, etc. The invention further provides a device manufacturing method, using a lithographic apparatus according to the invention, wherein the optical element is moved, in order to provide an optimum homogeneity for the projection beam of radiation.

Abstract: A method for exposing a resist layer on a substrate to an image of a pattern on a mask is disclosed whereby, after starting exposure and before completing exposure, a controlled amount of contrast loss is introduced by a controller in the image at the resist layer by changing during exposure the position of the substrate holder. The contrast loss affects the pitch dependency of the resolution of a lithographic projection apparatus, and its control is used to match pitch dependency of resolution between different lithographic projection apparatus.