Invention Application
- Patent Title: Inspection Systems and Methods for Extending the Detection Range of an Inspection System by Forcing the Photodetector into the Non-Linear Range
- Patent Title (中): 检测系统和方法通过强制光检测器进入非线性范围来扩展检测系统的检测范围
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Application No.: US11751293Application Date: 2007-05-21
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Publication No.: US20080291454A1Publication Date: 2008-11-27
- Inventor: Zhongping Cai , Alexander Slobodov , Anatoly Romanovsky , Christian H. Wolters
- Applicant: Zhongping Cai , Alexander Slobodov , Anatoly Romanovsky , Christian H. Wolters
- Applicant Address: US CA Milpitas
- Assignee: KLA-TENCOR TECHNOLOGIES CORP.
- Current Assignee: KLA-TENCOR TECHNOLOGIES CORP.
- Current Assignee Address: US CA Milpitas
- Main IPC: G01N21/55
- IPC: G01N21/55

Abstract:
An inspection system and method is provided herein for increasing the detection range of the inspection system. According to one embodiment, the inspection system may include a photodetector having a plurality of stages, which are adapted to convert light scattered from a specimen into an output signal, and a voltage divider network coupled for extending the detection range of the photodetector (and thus, the detection range of the inspection system) by saturating at least one of the stages. This forces the photodetector to operate in a non-linear manner. However, measurement inaccuracies are avoided by calibrating the photodetector output to remove any non-linear effects that may be created by intentionally saturating the at least one of the stages. In one example, a table of values may be generated during a calibration phase to convert the photodetector output into an actual amount of scattered light.
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