Exposure apparatus and method of manufacturing device
An exposure apparatus includes a first measurement device, a second measurement device, and a controller. The first measurement device measures the position of a substrate stage in the optical axis direction when the substrate stage is scanned in the first direction. The second measurement device measures the surface positions of the substrate in the optical axis direction at a plurality of measurement points on one straight line extending in the second direction on the substrate. The controller controls the second measurement device to measure at least one identical region on the substrate at different measurement points of the plurality of measurement points both before and after the substrate stage moves in steps in the second direction, and calculates a measurement error of the first measurement device attributed to the driving of the substrate stage in the second direction based on the measurement result obtained by the second measurement device.
1. An exposure apparatus which projects a pattern of a reticle onto a substrate via a projection optical system to scan-expose the substrate, the apparatus comprising:
a driving mechanism which scans a substrate stage that holds the substrate in a first direction perpendicular to an optical axis direction of the projection optical system, and moves the substrate stage in steps in a second direction perpendicular to the optical axis direction and the first direction;
a first measurement device which measures a position of the substrate stage in the optical axis direction of the projection optical system when said driving mechanism scans the substrate stage in the first direction;
a second measurement device which measures surface positions of the substrate in the optical axis direction of the projection optical system at a plurality of measurement points on one straight line extending in the second direction on the substrate; and
a controller,
wherein said controller controls said second measurement device to measure at least one identical region on the substrate at different measurement points of the plurality of measurement points both before and after the substrate stage moves in steps in the second direction, and calculates a measurement error of said first measurement device attributed to the driving of the substrate stage in the second direction based on the measurement result obtained by said second measurement device.
2. The apparatus according to claim 1 , wherein said controller reduces a width, across which the substrate stage moves in steps in the second direction, so that said second measurement device can measure at least one identical region on the substrate at different measurement points, in a mode of calculating a measurement error of said first measurement device.
3. The apparatus according to claim 1 , wherein said controller corrects the measurement result obtained by said first measurement device using the calculated measurement error of said first measurement device.
4. The apparatus according to claim 1 , wherein
said first measurement device includes a bar mirror and an interferometer, and
said controller determines a timing at which said bar mirror is measured based on the calculated measurement error of said first measurement device.
5. The apparatus according to claim 1 , wherein said second measurement device performs the measurements at different measurement points in at least one identical region on the substrate when the exposure apparatus is powered on, when an origin position of the substrate stage is determined, or when a first substrate in a lot to undergo an exposure process is loaded onto the substrate stage.
6. The apparatus according to claim 1 , wherein said second measurement device performs the measurements at different measurement points in at least one identical region on the substrate every time a predetermined number of substrates are processed or every time a predetermined time elapses.
7. The apparatus according to claim 1 , wherein said second measurement device performs the measurements at different measurement points in at least one identical region on the substrate for a substrate having no underlying pattern.
8. The apparatus according to claim 1 , wherein
the exposure apparatus includes an exposure region in which the substrate is exposed via the projection optical system, a measurement region in which the substrate is measured, and a plurality of substrate stages that can move between the exposure region and the measurement region, and exposes the substrate, measured in the measurement region, in the exposure region while positioning the substrate in accordance with the measurement result obtained in the measurement region, and
said first measurement device and said second measurement device are positioned in the measurement region.
9. The apparatus according to claim 1 , wherein the exposure apparatus exposes the substrate while positioning the substrate based on the measurement result obtained by said first measurement device.
10. A method of manufacturing a device, the method comprising the steps of:
exposing a substrate using an exposure apparatus according to claim 1 ; and
developing the substrate exposed; and
processing the developed substrate to manufacture the device.