| 摘要 |
PURPOSE:To improve the operating efficiency of a mask changer by providing a cassette charging hole with a door on the sidewall of a chamber, and providing a conveyor for delivering the mask at the inner sidewall of the chamber to eliminate the disorder of the inner atmosphere. CONSTITUTION:A hole 17 covered with a door 15 provided separately from a door for maintenance and inspection is formed at the side wall 2 of a chamber, and a plurality of cassettes 14 each of which contains a mask are provided. A conveyor 5 which forms a mask changer is provided at the sidewall 2. When the mask in response to an exposure pattern is selected, the conveyor 5 is driven to elevationally move a hand 11 to the selected cassette position, and a carrier 9 is horizontally slid to remove a mask. The chamber is held at positive pressure relative to the exterior to prevent dusts from invading to the chamber when the door 15 is opened to exchange the cassette 14. |
