| 摘要 |
PURPOSE:To enhance the measuring accuracy of a position by correcting the position detecting error caused by the deformation of a pattern or the deterioration due to surface treatment of said pattern, by simultaneously extracting a plurality of data lights having different properties from one pattern to independently process the same. CONSTITUTION:Some waveform data are selected from the signal waveform data respectively taken-in nine waveform extraction circuits 410 of a mark detection circuit 9 to be transmitted to a high speed operation memory MEM 420. A high speed operation exclusive processor BSP 422 reads the waveform data from the memory 420 to perform predetermined operation and detects the position of the diffraction lattice mark WM on a wafer from the characteristic of a waveform to transmit the same to a CPU 424 through a bus 415. The CPU 424 also controls nine waveform extraction circuits 410 and the memory 420 and converts the detected mark position data to the displacement of the wafer, that is, the measuring unit of an interferometer to send out the same to a main control circuit 8. Therefore, the position of the wafer is prescribed from the position of a stage when the stage is stopped to detect the mark WM and the position data from the CPU. |
