发明名称 |
Optical arrangement of autofocus elements for use with immersion lithography |
摘要 |
An autofocus unit is provided to an immersion lithography apparatus in which a fluid is disposed over a target surface of a workpiece and an image pattern is projected onto this target surface through the fluid. The autofocus unit has an optical element such as a projection lens disposed opposite and above the target surface. An autofocus light source is arranged to project a light beam obliquely at a specified angle such that this light beam passes through the fluid and is reflected by the target surface of the workpiece at a specified reflection position that is below the optical element. A receiver receives and analyzes the reflected light. Correction lenses may be disposed on the optical path of the light beam for correcting propagation of the light beam. |
申请公布号 |
US7414794(B2) |
申请公布日期 |
2008.08.19 |
申请号 |
US20050234279 |
申请日期 |
2005.09.26 |
申请人 |
NIKON CORPORATION |
发明人 |
NOVAK W. THOMAS |
分类号 |
G02B3/12;G03F7/20;G03F9/00 |
主分类号 |
G02B3/12 |
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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