Neutral atoms can be trapped and manipulated with surface mounted microscopic
current carrying and charged structures. We present a lithographic fabrication
process for such atom chips based on evaporated metal films. The size limit of
this process is below 1μm. At room temperature, thin wires can carry more
than 107A/cm2 current density and voltages of more than 500V. Extensive
test measurements for different substrates and metal thicknesses (up to 5
μm) are compared to models for the heating characteristics of the
microscopic wires. Among the materials tested, we find that Si is the best
suited substrate for atom chips