| 摘要 |
PURPOSE: To maintain a mask foil with in stress range allowed during operation by arranging a mask in a room controlled at a fixed temperature, forming a hole of a room wall in an irradiation line so as to be closed by shutters and arranging cooling faces in the visual field of the mask within the irradiation line. CONSTITUTION: Cooling faces 3, 3' consisting of a conductive material and having a temperature lower than the mask 8 are fixed between the mask 8 and an irradiation line source 1 and on the back of the mask 8 at an equal interval from the axial line of an irradiation line 2 so as to surround the line 2 and the interval from the axial line is set larger than the distance from the axial line of the line 2 on the edge of a mask foil area. The mask 8 is arranged in the room 4 controlled at a fixed temperature, the hole of the room wall in the line 2 can be closed by shutters 5, 7 forming a part of the room wall. When the mask 8 is arranged in the line 2 on the back of the hole, the cooling faces 3, 3' are controlled so as to be included within the visual field of the mask 8 so that the mask 8 is held at almost the room temperature. Consequently, the mask 8 is held in a flat state sufficiently free from distortion under the load of the irradiation line. |
