发明名称 |
Transmission shear grating in checkerboard configuration for EUV wavefront sensor |
摘要 |
A wavefront measurement system includes a source of electromagnetic radiation. An imaging system directs the electromagnetic radiation at an object plane that it uniformly illuminates. A first grating is positioned in the object plane to condition the radiation entering the input of a projection optic. A projection optical system projects an image of the first grating onto the focal plane. A second grating is positioned at the focal plane that receives a diffracted image of the object plane to form a shearing interferometer. A CCD detector receives the image of the pupil of the projection optical system through the projection optical system and the second grating that forms a fringe pattern if there are aberrations in the projection optical system. Phaseshift readout of fringe pattern can be accomplished by stepping the first grating in a lateral direction and reading each frame with the CCD detector.
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申请公布号 |
US7268891(B2) |
申请公布日期 |
2007.09.11 |
申请号 |
US20040750986 |
申请日期 |
2004.01.05 |
申请人 |
ASML HOLDING N.V. |
发明人 |
POULTNEY SHERMAN K. |
分类号 |
G01B9/02;G01B11/24;G01J9/02;G01M11/02;G02B5/18;G03F7/20;H01L21/027 |
主分类号 |
G01B9/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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