摘要 |
A load-lock apparatus including a load-lock chamber, a chuck, arranged in the load-lock chamber, to hold a substrate, a pressure reduction system to reduce a pressure in the load-lock chamber using an exhaust valve, a pressure measurement system to measure a pressure in the load-lock chamber, and a time measurement system to measure an operating time of the pressure reduction system. The exhaust valve is controlled such that a relationship between a pressure measured by the pressure measurement system and a time measured by the time measurement system falls within a predetermined range with respect to a predetermined relationship.
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