Stage device

• US 20070035267A1
• Filed: 09/18/2006
• Published: 02/15/2007
• Est. Priority Date: 03/19/2004
• Status: Active Grant

• Current Assignee: Sumitomo Heavy Industries Limited, Tohoku Techno Arch Co., Ltd.
• Original Assignee: Sumitomo Heavy Industries Limited, Tohoku Techno Arch Co., Ltd.
• Inventors: Gao, Wei, Kiyono, Satoshi, Tano, Makoto, Tomita, Yoshiyuki
• Granted Patent: US 7,257,902 B2
• Time in Patent Office: Days
• US Class Current: 318/649
• CPC Class Codes: G03F 7/70716 Stages
• CPC Class Codes: G03F 7/70775 Position control, e.g. interferometers or encoders for determining the stage position

Abstract

This invention relates to a stage device which is moved with high accuracy in an X-Y direction and a rotating direction using a planar motor. The invention is aimed at reducing the size of the stage device and at performing accurately measurement of a position of the stage to the base. The stage device comprises a scale unit having a scale part on the entire plane of the base, and three two-dimensional angle sensors disposed on a bottom surface of a movable stage part. The scale unit and the two-dimensional angle sensors form a surface encode. A position of the movable stage part is measured by the surface encoder.

Claims

1. A stage device comprising:

a base;

a stage carrying a movable body and being moved over the base;

a planar motor driving the stage;

an air bearing acting to lift the stage over the base;

a scale part disposed on the base to include an angle grating which has an angle-related characteristic varied in a two-dimensional direction in accordance with a known function; and

at least one two-dimensional angle sensor disposed on the stage so that the at least one two-dimensional angle sensor emits a light beam to the angle grating of the scale part and detects a two-dimensional angle of a light beam reflected from the scale part.

2. The stage device according to claim 1 wherein the scale part is covered with a protection member of a transparent material.

3. The stage device according to claim 1 wherein the stage device comprises two or more two-dimensional angle sensors including the at least one two-dimensional angle sensor.

4. The stage device according to claim 3 wherein is disposed so that the at least one two-dimensional angle sensor is adapted to measure at least one of a two-dimensional coordinate position, a pitching angle, a rolling angle and a yawing angle of the stage.

5. The stage device according to claim 4 wherein the two-dimensional coordinate position is represented by any of rectangular coordinates, cylindrical coordinates, polar coordinates, and free-form surface coordinates.

6. The stage device according to claim 4 wherein the at least one two-dimensional angle sensor is adapted to measure a distance between the scale part and the at least one two-dimensional angle sensor by giving a predetermined angle change to the at least one two-dimensional angle sensor.