Patent ID: 7019817

Claim:
An edge-holding aligner for detecting an orientation indicator formed in an edge of a disk-shaped substrate, adjusting a position of the substrate based on a detection result of the orientation indicator, and then holding the substrate, comprising: a base; a rotational arm supported on the base so as to be able to turn for angular displacement about a predetermined pivotal axis, the rotational arm being provided with a holder for holding an edge of the substrate in a state that an axis of the substrate is aligned with the pivotal axis; rotational arm driving means for driving the rotational arm for angular displacement about the pivotal axis; holder driving means for driving the holder for radial displacement along a radius of an imaginary circle having a center on the pivotal axis; first orientation indicator detecting means for detecting the orientation indicator, the first orientation indicator detecting means being mounted on the base so as to correspond to a path along which the edge of the substrate moves; second orientation indicator detecting means for detecting the orientation indicator, the second orientation indicator detecting means being mounted on the rotational arm so as to correspond to a path along which the edge of the substrate moves; angular position detecting means for detecting an angular position of the rotational arm about the pivotal axis; and control means for controlling the rotational arm driving means to turn the rotational arm for angular displacement, determining a position of the orientation indicator based on detected data provided by the second orientation indicator detecting means and the angular position detecting means while the rotational arm is being turned for angular displacement, controlling the rotational arm driving means to turn the rotational arm through an angle such that the holder and the orientation indicator are displaced circumferentially relative to each other.