| 摘要 |
<p>PURPOSE:To highly accurately align a semiconductor wafer without being affected by a circuit pattern formed on the surface of the semiconductor wafer. CONSTITUTION:At least two alignment marks are provided on the rear surface of a wafer 1 and, when the wafer 1 is placed on and fixed to a wafer chuck 2, the marks are optically detected with a detector 4 through mark detecting holes 3 provided through the chuck 2. Depending upon the detected states of the marks, the wafer 1 is finely aligned by moving and controlling the chuck 2 in the theta-, X-, and Y-directions by means of stages 6-8, respectively.</p> |
