A coating for sensors andor parts of an exposure apparatus, for example a sensor on a substrate table of a lithography apparatus, include a semiconductor, a photocatalyst, andor a metal oxide. The light unit is insertable into a substrate having a metalinsulationmetal sandwich structure. Second, the method may advance the optical marking mechanism from the track to a next track of the optically writable label side of the optical disc, such that a starting position on the track is radially non-collinear with a starting position on the next track. The engine may operate in one of a two-stroke and a four-stroke cycle. The resulting film is useful as a capacitative cell and resists oxygen diffusion to the underlying material, has high capacitance and low current leakage. In particular, the use of a filter made of sintered metal is proposed in order to avoid penetration of particles into a microstructured component, which can also contain a very fine filter in front of the nozzle.