Method of and apparatus for measuring coordinate position and positioning an object

An apparatus for measuring a position of a stage moved in a predetermined direction, the stage having a first plane mirror extending in said predetermined direction and a second plane mirror extending in a direction perpendicular to the predetermined direction, comprising:

• a light wave interferometer for measuring a change in the distance to a reflecting surface of said first plane mirror in a direction perpendicular to the reflecting surface;
• first and second measuring means for measuring local curving deviations of the reflecting surfaces of said first and second plane mirrors with respect to the directions in which the reflecting surfaces extend, respectively;
• storage means substantially simultaneously supplied with measured values obtained from said first and second measuring means when the stage is moved in said predetermined direction, said storage means obtaining and storing data according to the difference between the measured values in correspondence with the position of said stage;
• and
• means for determining a position of the stage measured with said light wave interferometer on the basis of the change in the distance and the data stored in said storage means.

A method of measuring a position of a mark on a stage moved in a predetermined direction, the stage having a first plane mirror extending in said predetermined direction and a second plane mirror extending in a direction perpendicular to the predetermined direction, comprising the steps of:

• (a) measuring a change in the distances to a reflecting surface of said first plane mirror in a direction perpendicular to the reflecting surface by a light wave interferometer, while detecting said mark by mark detecting means deviated from the measurement axis of the light wave interferometer;
• (b) measuring local rotational deviations of reflecting surfaces of said first and second plane mirrors with respect to the directions in which the reflecting surfaces extend, respectively;
• (c) obtaining the curving deviations of the reflecting surface of said first plane mirror on the basis of different between measured values obtained in step (b), and obtaining the extent of yawing of the stage with respect to said predetermined direction on the basis of at least one of the rotational deviations measured in step (b) corrected according to the curving deviations;
• and
• (d) correcting a position of the mark measured by the mark detecting means on the basis of the extent of yawing.

An apparatus for measuring a position of a mark on a stage moved in a predetermined direction, the stage having a first plane mirror extending in said predetermined direction and a second plane mirror extending in a direction perpendicular to the predetermined direction, comprising:

• a light wave interferometer for measuring a change in the distance to a reflecting surface of said first plane mirror in a direction perpendicular to the reflecting surface;
• mark detecting means for detecting said mark on the stage at a position deviated from a measurement axis of said light wave interferometer;
• first and second rotational deviation measuring means for measuring local rotational deviations of the reflecting surfaces of said first and second plane mirrors with respect to the directions in which the reflecting surfaces extend, respectively;
• means for obtaining the curving deviations of the reflecting surface of said first plane mirror on the basis of the difference between the measured values obtained by said first and second rotational deviation measuring means, and for obtaining the extent of true yawing of the stage with respect to said predetermined direction by correcting the rotational deviations measured by at least one of said first and second rotational deviation measuring means according to the curving deviations;
• and
• correction means for correcting a position of the mark measured by the mark detecting means on the basis of the extent of yawing.

A method in which a pattern is projected on a substrate retained on a stage provided with a first plane mirror having a reflecting surface extending in a predetermined direction and a second plane mirror having a reflecting surface extending in a direction perpendicular to said predetermined direction, and in which the stage is moved in said predetermined direction and is positioned so that a predetermined positional relationship is established between the projected pattern and the substrate, said method comprising the steps of:

• (a) measuring a change in the distances to the reflecting surface of said first plane mirror in a direction perpendicular to the reflecting surface by a light wave interferometer while detecting a beam on said first plane mirror;
• (b) separately measuring local rotational deviations of the reflecting surfaces of said first and second plane mirrors, respectively;
• (c) determining the extent of true yawing of the stage with respect to said predetermined direction on the basis of the measured values separately obtained in step (b) while removing the influence of curving deviations of the reflecting surfaces of said first plane mirror;
• and
• (d) correcting a rotational error due to the yawing by relatively rotating the projected pattern and the substrate according to the extent of true yawing.

An apparatus in which a pattern is projected on a substrate retained on a stage moved in a predetermined direction and the stage is positioned so that a predetermined region on the substrate coincides with the projected pattern, comprising:

• first and second plane mirrors provided on the stage and having reflecting surfaces respectively extending in said predetermined direction and a direction perpendicular to said predetermined direction;
• a light wave interferometer for measuring a change in the distances to said first plane mirror;
• a pair of rotational deviation measuring means for separately measuring local rotational deviations of the reflecting surfaces of said first and second plane mirrors with respect to the directions in which the reflecting surfaces extend;
• means for obtaining the curving deviations of the reflecting surfaces of said first and second plane mirrors on the basis of the difference between the measured values obtained by said pair of rotational deviation measuring means;
• means for obtaining the extent of true yawing of the stage by correcting the rotational deviations measured by at least one of said pair of rotational deviation measuring means according to the curving deviations;
• and
• rotational correction means for relatively rotating the substrate and the projected pattern on the basis of the extent of true yawing when the stage is positioned so that the predetermined region on the substrate and the projected pattern coincide.