Patent ID: 8237139
Filing Date: 2012-08-07
Classification: B82Y,G03B,H01J

Abstract:
1. A substrate position detecting method for charged particle beam photolithography apparatus, the method comprising: placing a substrate on a stage configured to move horizontally in an X-direction and a Y-direction, the X-direction and Y-direction being orthogonal to each other; measuring a position in the X-direction of the stage while moving the stage in the X-direction, and illuminating obliquely an upper surface of the substrate with a laser beam to receive light reflected from the substrate with a position sensing device (PSD); computing a barycentric position of the reflected light when the stage is moved in the X-direction; measuring a position in the Y-direction of the stage while moving the stage in the Y-direction, and illuminating obliquely the upper surface of the substrate with the laser beam to receive light reflected from the substrate with the position sensing device (PSD); computing a barycentric position of the reflected light when the stage is moved in the Y-direction; and computing the positions in the X-direction and Y-direction of the substrate from the position measurement results in the X-direction and Y-direction of the stage and the computed barycentric positions.