Decreasing inaccuracy due to non-periodic effects on scatterometric signals

US9851300B1 · kind B1 · utility

Assignee

• KLA-TENCOR CORPORATION · US

Inventors

• Barak Bringoltz · Rehovot, IL
• Ofer Zaharan · Jerusalem, IL
• Amnon Manassen · Haifa, IL
• Nadav Carmel · Mevaseret Tsiyon, IL
• Victoria Naipak · Barak, IL
• Alexander Svizher · Haifa, IL
• Tzahi Grunzweig · Hillsboro, US
• Daniel Kandel · Aseret, IL

Key dates

• Filing date: Apr 3, 2015
• Grant date: Dec 26, 2017
• Expiry date: Apr 3, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70633
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Methods and metrology modules and tools are provided, which minimize an estimated overlay variation measure at misalignment vector values obtained from a derived functional form of an overlay linear response to non-periodic effects. Provided methods further quantifying target noise due to the non-periodic effects using multiple repeated overlay measurements of the target cells, calculating an ensemble of overlay measurements between the cells over the multiple measurement repeats and expressing the target noise as a statistical derivative of the calculated overlay measurements. Sub-ensembles may be selected to further characterize the target noise. Various outputs include optimized scanning patterns, target noise metrics and recipe and target optimization.