Exposure mask adapted for position detecting with oblique incident light
AssigneeSumitomo Heavy Industries, Ltd.
InventorTsutomu Miyatake
Life of this patent
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Abstract
A wafer with an exposure surface and an exposure mask are disposed, directing the exposure surface to the exposure mask with a gap being interposed therebetween, the wafer having a position aligning wafer mark formed on the exposure surface, the wafer mark having a linear or point scattering source for scattering incident light, and the exposure mask having a position aligning mask mark having a linear or point scattering source for scattering incident light. A relative position of the wafer and exposure mask is detected by applying illumination light to the wafer mark and mask mark and observing scattered light from the scattered sources of the wafer mark and mask mark.
Claims7
An exposure mask adapted for use in a position detector with incident light having an optical axis which is oblique with respect to a surface of the exposure mask, the exposure mask comprising:
- a position aligning mask mark having a plurality of edge type or point type scattering sources for scattering the incident light having an optical axis oblique to a surface of the exposure mask, and
- wherein each of said scattering sources is oriented in a direction which is perpendicular to a plane of incidence of said incident light defined by the optical axis and a line normal to the surface of the exposure mask.
Dependencies are inferred from the claim text.