Direct deposition of Mo microstructures on Si is demonstrated by photolytic decomposition of condensed Mo(CO)6using the aperture‐limited, high‐intensity radiation from an undulator at the BESSY storage ring. A particular advantage of the instrument, a new photon‐induced scanning Auger microscope, is the possibility of quasisimultaneous exposure (writing) and analysis employing photoemission (PES) or x‐ray induced Auger spectroscopy (XAES) with sufficient energy resolution for detection of chemical differences. The present spatial resolution is 20–30 &mgr;m (for PES and writing) and 3 &mgr;m (for XAES), but this will be improved by adding focusing mirrors. ©1995 American Institute of Physics.