Method of determining a focus position for a substrate exposure process and substrate exposure apparatus capable of performing the same
First Claim
1. A method of determining a focus position for a substrate exposure process, the method comprising:
- illuminating a reticle having a plurality of light-transmitting regions with an off-axis illumination light having a plurality of poles;
focusing a projected light passing through the plurality of light-transmitting regions onto a projection plane;
measuring an intensity of the projected light at the projection plane, the intensity of the projected light having a plurality of peaks of intensity; and
determining the focus position based on a distance between the plurality of peaks of intensity.
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Accused Products
Abstract
In a method of determining a focus position for a substrate exposure process and a substrate exposure apparatus capable of performing the same, a reticle having a light-transmitting region may be illuminated by an off-axis illumination light. A projected light, which is transmitted through the reticle and a projection optical system, may be detected by a light sensor disposed on a substrate stage. An intensity of the projected light measured at a light-receiving surface of the light sensor may vary in accordance with positions of the light-receiving surface. The focus position may be determined based on the variations in the intensity of the projected light.
5 Citations
16 Claims
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1. A method of determining a focus position for a substrate exposure process, the method comprising:
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illuminating a reticle having a plurality of light-transmitting regions with an off-axis illumination light having a plurality of poles; focusing a projected light passing through the plurality of light-transmitting regions onto a projection plane; measuring an intensity of the projected light at the projection plane, the intensity of the projected light having a plurality of peaks of intensity; and determining the focus position based on a distance between the plurality of peaks of intensity. - View Dependent Claims (2, 3, 4, 5, 6, 14, 15, 16)
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7. A substrate exposure apparatus, comprising:
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an illumination optical system providing an off-axis illumination light having a plurality of poles; a reticle stage supporting a reticle having a plurality of light-transmitting regions, the reticle being illuminated by the off-axis illumination light; a projection optical system focusing projected light passing through the reticle; a substrate stage having a substrate holder for holding a substrate; a light sensor disposed adjacent to the substrate holder to measure an intensity of the projected light having a plurality of peaks of intensity, the light sensor having a projection plane where the projected light is focused thereon; and a focusing system for determining a focus position based on a distance between the plurality of peaks of intensity. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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Specification