| 摘要 |
PURPOSE:To enable the repeated exposure even for a wafer of poor flatness by making a relative position of the wafer with a mask extremely close by positioning a wafer with a mask when the wafer rises after movement to a new position and a distance from the mask becomes a minute one required for the exposure. CONSTITUTION:When a mask and a wafer approach to each other, an electrostatic capacity between electrode 3-6 and the wafer 5 increases. Then it is measured to control the distance between the mask and wafer. The wafer is lowered to a safe distance before the movement and is raised after the movement to a new position. When the distance from the mask becomes the minute one that is required for the exposure, positioning with the mask and the subsequent exposure are carried out. Usually, a main body of the mask is formed of an insulator and the pattern is of a conductor so that an electrode for distance measurement and a printed pattern can be fabricated on the same plane at the same time and the measurement electrode can be arranged in the position extremely close to the printed pattern. |
