| 摘要 |
PROBLEM TO BE SOLVED: To provide a measurement device of which the grating mark position measurement speed is accelerated.SOLUTION: A measurement device 50 that measures positions of grating marks GMa and GMb provided on a wafer W comprises: an illumination system 70 which irradiates the wafer W moving in a Y-axis direction with measurement light L1 and L2 to generate an illumination region of which the length in the Y-axis direction is longer than the grating marks GMa and GMb on the wafer W; a diffraction gating 66 in which an image based on reflection light of the measurement light L1 and L2, from the wafer W, including reflection diffraction light from grating marks GM1 and GM2 is formed; a detection system 80 including a detection optical system 86 for detecting a portion where an image of the diffraction grating 66 and an image based on the reflection diffraction light are overlapped, when moving the grating marks GMa and GMb in the Y-axis direction within the illumination region, and a detector 84 for detecting an image that is extracted by the detection optical system 86; and a calculation system for calculating positional information of the grating marks GMa and GMb on the basis of output of the detection system 80.SELECTED DRAWING: Figure 3 |
