Evaporated metal layers with a high uniformity may be obtained by using a system of parallel wires as evaporation source. The distribution of the film thickness is discussed for a simple system of two parallel wires. If the two wires are properly spaced with respect to the receiving surface a maximally flat distribution of film thickness may be obtained. A special example of a system with 12 parallel wires is treated in detail. The method has been used for producing thin films for precision microwave attenuators as well as for semi-transparent and dissipative devices in the microwave range.
MARTIN V. SCHNEIDER, "Method for Obtaining Uniform Evaporated Layers," J. Opt. Soc. Am. 50, 18-18 (1960)