发明名称 |
AN OPTICAL FOCUS SENSOR, AN INSPECTION APPARATUS AND A LITHOGRAPHIC APPARATUS |
摘要 |
<p>To detect whether a substrate is in a focal plane of an inspection apparatus, an optical focus sensor is arranged to receive a radiation beam via an objective lens. The optical focus sensor includes a splitter configured to split the radiation beam into a first sub-beam and a second sub- beam. With an aperture and a detector in the light path of each of the sub-beams it is possible to detect whether the substrate is in focus by comparing the amount of radiation received by each of the detectors. Figure 4a</p> |
申请公布号 |
SG152162(A1) |
申请公布日期 |
2009.05.29 |
申请号 |
SG20080075749 |
申请日期 |
2008.10.09 |
申请人 |
ASML NETHERLANDS B.V. |
发明人 |
KALF, WILLEM;HUGERS, RONALD, FRANCISCUS, HERMAN |
分类号 |
|
主分类号 |
|
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|