WAFER ALIGNMENT DEVICE AND ALIGNMENT THEREOF

摘要

PURPOSE:To improve the alignment speed of a wafer without being affected by the position of the wafer set on a rotating table, the accuracy of the manufacture of the wafer and the like by a method wherein a wafer alignment device is provided with a holder for positioning the outline of the wafer in advance and mechanically before the wafer is matched using an optical means, the amounts of eccentricity are stored each time the wafer is aligned, a statistical processing is performed along with the stored amounts of eccentricity and an error amount is corrected. CONSTITUTION:A fixing holder 21 is made to ascend to a wafer 1 set on a rotating table 2, then, a movable holder 22 is moved to the side of the wafer 1, whereby the wafer 1 is pressed to the holder 21 by a pin 23 of the holder 22. The pressed wafer 1 negotiates with a pin 23 on the holder 21, is inducted by the pin 23 and is positioned to the pin 23 of the holder 21. Then, the wafer 1 is sucked in a vacuum by the table 2, the holders 21 and 23 are turned to the positions of their origins and a positioning of the wafer is performed. After an alignment processing using a holder 3 is finished, the amounts (DELTAX and DELTAY) of eccentricity between the center 24 of the wafer and a center 25 of rotation are calculated by a formula (1). Moreover, the frequency distributions of the amounts of eccentricity stored in the past are taken, the most frequency value within the frequency distributions is detected, the amount of statistics is calculated by averaging the amounts of eccentricity within the most frequency value and an error value is corrected.