发明授权
US07230704B2 Diffracting, aperiodic targets for overlay metrology and method to detect gross overlay
有权
用于覆盖计量的衍射，非周期性目标和检测总重叠的方法
- 专利标题： Diffracting, aperiodic targets for overlay metrology and method to detect gross overlay
- 专利标题（中）： 用于覆盖计量的衍射，非周期性目标和检测总重叠的方法
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申请号： US10858691申请日： 2004-06-02
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公开(公告)号： US07230704B2公开(公告)日： 2007-06-12
- 发明人: Abdurrahman Sezginer , Hsu-Ting Huang , Kenneth Johnson
- 申请人： Abdurrahman Sezginer , Hsu-Ting Huang , Kenneth Johnson
- 申请人地址： JP Tokyo
- 专利权人： Tokyo Electron Limited
- 当前专利权人： Tokyo Electron Limited
- 当前专利权人地址： JP Tokyo
- 代理机构： Stallman & Pollock LLP
- 主分类号： G01B11/00
- IPC分类号： G01B11/00
摘要：
A method for measuring overlay in semiconductor wafers includes a calibration phase in which a series of calibration samples are analyzed. Each calibration sample has an overlay that is known to be less than a predetermined limit. A difference spectrum for a pair of reflectively symmetric overlay targets is obtained for each calibration sample. The difference spectra are then combined to define a gross overlay indicator. In subsequent measurements of actual wafers, difference spectra are compared to the overlay indicator to detect cases of gross overlay.
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