Method of evaporating melts of alloys of metals having different vapor pressures

Method for evaporating melts of alloys of metals of different vapor pressures from a continuously fed, large-area evaporating crucibles by direct bombardment of the bath surface with focused electron beams which are periodically deflected according to a pattern wherein the alloy material is deposited on a plurality of substrates which are disposed in a field above the evaporating crucible with local adaptation of the energy density to the thermal economy of the melt bath which comprises deflecting at least one electron beam onto at least two substantially rectangular beam fields F.sub.1, F.sub.2 . . . , guiding the electron beam in each of these fields through a line raster at a frequency of at least 100 Hz, shifting periodically from one to the other field at a shift frequency of at most 5 Hz, the dwell time of the electron beam within each field being selected at T.sub.1, T.sub.2, . . . ;

• the area ratios of the beam fields F.sub.1, F.sub.2 and the relative dwell times T.sub.1, T.sub.2 being adjustable independently of one another, and the sum of the areas of all beam fields being between 10% and 80% of the area of the bath surface.