Automated measurement and analysis of sidewall roughness using three-dimensional atomic force microscopy

• Published in: Applied microscopy Vol. 52; no. 1; pp. 1 - 8
• Main Authors: Yoo, Su-Been, Yun, Seong-Hun, Jo, Ah-Jin, Cho, Sang-Joon, Cho, Haneol, Lee, Jun-Ho, Ahn, Byoung-Woon
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 08.03.2022; Springer Nature B.V; SpringerOpen; 한국현미경학회
• Subjects: 3D-AFM; AFM; Algorithms; Atomic force microscopes; Atomic force microscopy; Automation; Chemistry and Materials Science; Computer architecture; Field effect transistors; Materials Science; Mathematical analysis; Measurement and analysis; Metrology and inspection; Microscopes; Reproducibility; Roughness; Semiconductor devices; Sidewall roughness; 자연과학일반; AFM; Sidewall roughness; 3D-AFM; Metrology and inspection; Measurement and analysis
• ISSN: 2287-4445; 2287-5123; 2287-4445
• DOI: 10.1186/s42649-022-00070-5

As semiconductor device architecture develops, from planar field-effect transistors (FET) to FinFET and gate-all-around (GAA), there is an increased need to measure 3D structure sidewalls precisely. Here, we present a 3-Dimensional Atomic Force Microscope (3D-AFM), a powerful 3D metrology tool to measure the sidewall roughness (SWR) of vertical and undercut structures. First, we measured three different dies repeatedly to calculate reproducibility in die level. Reproducible results were derived with a relative standard deviation under 2%. Second, we measured 13 different dies, including the center and edge of the wafer, to analyze SWR distribution in wafer level and reliable results were measured. All analysis was performed using a novel algorithm, including auto flattening, sidewall detection, and SWR calculation. In addition, SWR automatic analysis software was implemented to reduce analysis time and to provide standard analysis. The results suggest that our 3D-AFM, based on the tilted Z scanner, will enable an advanced methodology for automated 3D measurement and analysis.