Projection exposure method and apparatus
AssigneeNikon Corporation
InventorKazuaki Suzuki
Life of this patent
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Abstract
A transfer method comprises the first step of disposing a mask and a substrate with a projection optical system interposed therebetween in planes substantially perpendicular to the optical axis thereof; and the second step of moving the image plane of the projection optical system and the substrate relative to each other in the direction of the optical axis in conformity with a variation in the positional relationship between the mask and the projection optical system in the direction of the optical axis of the projection optical system while the mask and the substrate are moved in a predetermined direction perpendicular to the optical axis of the projection optical system, in order to transfer a pattern on the mask onto the substrate.
Claims11
A scanning exposure method in which a mask is moved in a scanning direction relative to an illuminated area of an exposure beam and an image of a pattern formed on the mask is projected onto a substrate through a projection system, the method comprising:
- measuring, prior to a scanning exposure of the substrate, positional variation of an image surface formed through the projection system while said mask is moved in the scanning direction, the positional variation of the image surface being caused by change of a positional condition of a pattern surface of said mask along an optical axis of the projection system within the illuminated area while moving the mask in the scanning direction;
- and
- performing, during the scanning exposure, an imaging adjustment in accordance with the measured positional variation of the image surface in order to form a desired image on the substrate.
A scanning exposure method comprising:
- relatively moving a mask and an illuminated area of an exposure beam during a scanning exposure, an image of a pattern of said mask being projected onto a substrate;
- and
- performing, during the scanning exposure, an imaging adjustment in order to compensate for change of the image projected onto the substrate that would be caused by a scanning surface error of the mask.
Dependencies are inferred from the claim text.