SWIR oblique-scanning scatterometry with global sensitivity analysis and back focal plane imaging for hidden HAR microstructure critical dimension measurement
Journal
Proceedings of SPIE - The International Society for Optical Engineering
Journal Volume
13567
Start Page
135671M
ISSN
0277786X
ISBN (of the container)
9781510690424
ISBN
9781510690424
Date Issued
2025-08-08
Author(s)
Kuo, Bo-Chen
Yang, Fu-Sheng
Das, Surajit
Lin, Yuan-Ci
Chou, Wei-Xiang
Huang, Ting-Hui
Najera, Luis
Abstract
Advancements in 3D integrated circuits (3DIC) and Chip-on-Wafer-on-Substrate (CoWoS) packaging demand precise metrology of high aspect ratio (HAR) microstructures, challenging conventional inline measurement techniques. Traditional back focal plane (BFP) scatterometry offers high sensitivity to lateral critical dimensions (CDs) but lacks depth resolution. To address this, we present a hybrid visible-to-shortwave infrared (SWIR) spectroscopic scatterometry system that combines BFP scatterometry with spectroscopic reflectometry. A low numerical aperture (NA) normal incidence configuration and angle-scanning module are employed to enhance depth sensitivity and lateral CD accuracy, respectively. The SWIR range improves bottom CD and sidewall angle assessment due to deeper penetration. Global sensitivity analysis (GSA) guides system optimization, and BFP imaging supports lateral CD extraction. Experimental validation demonstrates CD measurement errors under 1.95%, confirming the system's precision for HAR metrology.
Event(s)
14th Optical Measurement Systems for Industrial Inspection, Munich, 23 June 2025 - 27 June 2025
Subjects
Back Focal Plane
Global Sensitivity Analysis
High Aspect Ratio Structure
Hybrid Metrology
Scatterometry
Publisher
SPIE
Type
conference paper