Three-dimensional surface metrology of wafers

US11662324B1 · kind B1 · utility

Assignee

• Applied Materials Israel Ltd. · IL

Inventors

• Ido Almog · Rehovot, IL
• Ron Bar-Or · Ramat Gan, IL
• Lior Yaron · Nes Ziona, IL

Key dates

• Filing date: Mar 18, 2022
• Grant date: May 30, 2023
• Expiry date: Mar 18, 2042

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2223/6116
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A computer-based method for three-dimensional surface metrology of samples based on scanning electron microscopy and atomic force microscopy. The method includes: (i) using a scanning electron microscope (SEM) to obtain SEM data of a set of sites on a surface of a sample; (ii) using an atomic force microscope (AFM) to measure vertical parameters of sites in a calibration subset of the set; (iii) calibrating an algorithm, configured to estimate a vertical parameter of a site when SEM data of the site are fed as inputs, by determining free parameters of the algorithm, such that residuals between the algorithm-estimated vertical parameters and the AFM-measured vertical parameters are about minimized; and (iv) using the calibrated algorithm to estimate vertical parameters of the sites in the complement to the calibration subset.