Invention Grant
- Patent Title: Statistical overlay error prediction for feed forward and feedback correction of overlay errors, root cause analysis and process control
- Patent Title (中): 反馈前馈和反馈校正的统计叠加误差预测,根本原因分析和过程控制
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Application No.: US14220665Application Date: 2014-03-20
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Publication No.: US09087176B1Publication Date: 2015-07-21
- Inventor: Wei Chang , Krishna Rao , Joseph Gutierrez , Ramon Olavarria , Craig Macnaughton , Amir Azordegan , Prasanna Dighe , Jaydeep Sinha
- Applicant: KLA-Tencor Corporation
- Applicant Address: US CA Milpitas
- Assignee: KLA-Tencor Corporation
- Current Assignee: KLA-Tencor Corporation
- Current Assignee Address: US CA Milpitas
- Agency: Suiter Swantz pc llo
- Main IPC: G06F17/50
- IPC: G06F17/50 ; G03F7/20 ; G03F1/36 ; G03F1/00

Abstract:
A method to collect data and train, validate and deploy statistical models to predict overlay errors using patterned wafer geometry data and other relevant information includes selecting a training wafer set, measuring at multiple lithography steps and calculating geometry differences, applying a plurality of predictive models to the training wafer geometry differences and comparing predicted overlay to the measured overlay on the training wafer set. The most accurate predictive model is identified and the results fed-forward to the lithography scanner tool which can correct for these effects and reduce overlay errors during the wafer scan-and-expose processes.
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