摘要 |
An apparatus for evaporating materials to be deposited onto a substrate provides heat directly to the material to be evaporated by conduction and includes a means for compensating for thermal expansion and contraction of the heat source during thermal cycling. Direct heating provides a quicker response time which is critical for effective performance when making thin film semiconductors by elemental evaporation in a high vacuum chamber. Compensating for expansion leaves the heater uniform, devoid of hot or cold spots encountered when conventional heater elements buckle during thermal cycling.
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