Thermal Evaporation Resistive evaporation is a commonly-used vacuum deposition process in which electrical energy is used to heat a boat containing the charge or a filament that heats the material to be deposited up to the point of evaporation. The vapour condenses in the form of a thin film on the cold substrate surface. The method is restricted to materials with moderately low melting points to avoid contamination by the boat, which is usually made of graphite, molybdenum,
or tungsten.