Substrate position correcting method and apparatus using either substrate radius or center of rotation correction adjustment sum

A substrate processing apparatus which performs predetermined processing on a substrate while holding and rotating the substrate, comprising:

• a substrate rotating mechanism having a predetermined center of rotation, the substrate rotating mechanism rotating said substrate about said predetermined center of rotation while supporting the substrate in such a manner that said substrate can freely slide in a horizontal direction, and holding said substrate by a force of friction developed at said substrate;
• and
• a position correcting mechanism which exerts in the horizontal direction a greater force than said force of friction upon said substrate held on said substrate rotating mechanism, makes said substrate slide toward the center of rotation of said substrate rotating mechanism, and accordingly corrects the position of said substrate in the horizontal direction,
• wherein said position correcting mechanism comprises:
• a detector which detects an edge surface position of the edge surface of said substrate rotated by said substrate rotating mechanism which is a farthest from the center of rotation of said substrate rotating mechanism;
• a single pressing member which has an abutting section abutting on the edge surface of said substrate and presses said substrate along the horizontal direction;
• a driver which drives said pressing member to move said abutting section of said pressing member between a preset position which is away in the horizontal direction from the center of rotation of said substrate rotating mechanism by a distance which is equal to one of the radius of said substrate, and a distance which is the sum of a positive tolerance value for a target positioning accuracy and the radius of said substrate, and a separated position which is located farther than said preset position away from the center of rotation of said substrate rotating mechanism, said preset position, said separated position and the center of rotation being set in a same straight line in a horizontal plane;
• and
• a controller which stops said substrate rotating mechanism at a position where the farthest edge surface position detected by said detector is also in said straight line, and controls said driver to drive said pressing member to move said abutting section from said separated position to said preset position after stopping said substrate rotating mechanism,
• whereby said substrate is pushed by said pressing member, said abutting section abutting on the farthest edge surface position, toward the center of rotation of said substrate rotating mechanism until the farthest edge surface position detected by said detector matches with said preset position,
• wherein said substrate rotating mechanism comprises:
• a rotating member configured to rotate freely;
• a rotator unit which rotates said rotating member about said center of rotation;
• plural first support pins which are disposed projecting upwardly from said rotating member, abut on the bottom surface of said substrate, hold said substrate at said rotating member utilizing the force of friction developing at the bottom surface of said substrate;
• plural second support pins which are disposed projecting upwardly from said rotating member, abut on the bottom surface of said substrate, hold said substrate at said rotating member utilizing the force of friction developing at the bottom surface of said substrate, a coefficient of friction of the second support pins against the bottom surface of said substrate being larger than that of said first support pins, and
• a second controller which causes said first support pin group to abut alone on the bottom surface of said substrate when said position correcting mechanism is to correct the position of said substrate along the horizontal direction, and causes said second support pin group to at least abut on the bottom surface of said substrate when said predetermined processing is performed on said substrate.