摘要 |
An inactive gas is introduced into an organic material evaporation source to place a thin organic film material in the organic material evaporation source in an atmosphere having a relatively high pressure, and the temperature of the thin organic film material is increased up to a certain temperature. Then, the organic material evaporation source is evacuated to lower the pressure around the thin organic film material for thereby causing the thin organic film material to emit a vapor. Since no wasteful vapor is emitted from the thin organic film material, the thin organic film material is effectively utilized. Because the inactive gas acts as a heating medium, the temperature of the thin organic film material is increased at a high rate, and the thin organic film material is uniformly heated. When the temperature of the thin organic film material is lowered in an inactive gas atmosphere, it can be lowered at a high rate. The inactive gas is introduced directly into the organic material evaporation source by an on-off valve, the time required to evacuate the organic material evaporation source is reduced. A liquid thin organic film material may be heated by a heating medium in the organic material evaporation source, so that the liquid thin organic film material will not be heated to a temperature higher than the temperature of the heating medium, and hence will not suffer bumping due to a temperature overshooting.
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