Patent ID: 7075621

Claim:
An alignment method for a substrate, comprising: providing an alignment apparatus including: a movement mechanism configured to move the substrate in a horizontal direction and in a vertical direction, a rotation mechanism configured to rotate the substrate in a horizontal plane, an illumination tool configured to irradiate the substrate with an illumination light, an image sensor configured to pick up an image of the substrate, an edge position sensor configured to sense a plurality of edge positions of the substrate, and a computer; transferring the substrate from a previous stage using the first movement mechanism; measuring a position of the substrate by picking up an image on a back surface of the substrate using the image sensor while irradiating the substrate with the illumination light from a sidewise direction; calculating positional shifts regarding X, Y, and Î¸ using the edge position sensor and the computer; correcting the positional shifts of X and Y by the movement mechanism; mounting the substrate on a rotational stage; correcting the positional shift of Î¸ by the rotation mechanism; and transferring the substrate to a next stage.