| 摘要 |
PURPOSE:To execute main alignment automatically, and to improve the working efficiency of a device by positively positioning a fined target mark within the range of detection. CONSTITUTION:Signals taken in from a linear image sensor 5 are housed to a memory 8-1 through a driver 7. Signals close to a previously memorized wafer target mark are housed in a memory 8-2. A CPU9 compares the detecting signals of the memory 8-1 and the memorizing signals of the memory 8-2, and detects a position where a difference between areas is minimized. The quantity of displacement as the result is inputted to motor drivers 10-1, 10-2, motors 11-1, 11-2 are driven, and a wafer 1 is moved. The target mark is positioned positively within the range of detection through a series of such operation. Accordingly, main alignment is automated. |
