If I'm not mistaken, evaporation is intrinsically a thermal process.  I'm
therefore a bit puzzled by repeated references on this forum to "thermal"
evaporation. (What other kind is there?)  The two means by which heat is
commonly applied to an evaporation source are hot filament and electron beam.
To evaporate materials with high boiling point, (thermal) evaporation by e-beam
would be the preferred method.

Roger Shile