Determining the impacts of stochastic behavior on overlay metrology data

US10901325B2 · kind B2 · utility

Assignee

• KLA-TENCOR CORPORATION · US

Inventors

• Evgeni Gurevich · Givatayim, IL
• Michael Adel · Zichron Ya'akov, IL
• Roel Gronheid · Grez-Doiceau, BE
• Yoel Feler · Haifa, IL
• Vladimir Levinski · Milpitas, US
• Dana Klein · Haifa, IL
• Sharon Aharon · Hanaton, IL

Key dates

• Filing date: Feb 27, 2018
• Grant date: Jan 26, 2021
• Expiry date: Jan 31, 2039

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J37/28
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

Methods are provided for designing metrology targets and estimating the uncertainty error of metrology metric values with respect to stochastic noise such as line properties (e.g., line edge roughness, LER). Minimal required dimensions of target elements may be derived from analysis of the line properties and uncertainty error of metrology measurements, by either CDSEM (critical dimension scanning electron microscopy) or optical systems, with corresponding targets. The importance of this analysis is emphasized in view of the finding that stochastic noise may have increased importance with when using more localized models such as CPE (correctables per exposure). The uncertainty error estimation may be used for target design, enhancement of overlay estimation and evaluation of measurement reliability in multiple contexts.