| 摘要 |
PURPOSE:To detect relative position deviation highly accurately by setting parameters such as the shapes and the arrangements of alignment marks and the incident angles of luminous fluxes so that the incident states of two luminous fluxes have the adequate relationship. CONSTITUTION:The pattern shapes, the arrangements and the like of alignment marks 3, 4, 5 and 6 are set beforehand so that the incident positions of luminous fluxes 7 and 8 in the direction of X agree on the surfaces of the first and second detecting parts. The angle, which is formed between the incident positions of the luminous fluxes 7 and 8 with respect to the center of the alignment mark when the relative position deviation amount between a first object and a second object in the direction of X is zero, is made smaller than the angle when the position is deviated and made to be the smallest value. Each sensor measures the position of the center of gravity of the incident luminous flux. The output of the sensor undergoes signal processing so that the output is standardized with the total optical amount in a light receiving region. When there is the position deviation of 0.01 mum between a mask and a wafer, the effective movement of the center of gravity of 1 mum occurs on the surface of the sensor. The sensor system can measure the movement in resolution of 0.2 mum. |
