Enhanced critical dimension metrology of semiconductor packaging via dual-band scatterometry and sequential optimization
Journal
Measurement Science and Technology
Journal Volume
37
Journal Issue
24
Start Page
245012
ISSN
09570233
Date Issued
2026-06
Author(s)
Abstract
As semiconductor manufacturing advances toward heterogeneous integration, accurate and non-destructive metrology of submicron critical dimensions is essential for advanced packaging. Conventional optical scatterometry is limited by the high-dimensional simulation databases required for inverse modeling, resulting in prohibitively high computational costs. This work presents a new dual-band scatterometry system that integrates short-wave infrared (SWIR, 980-1640 nm) and deep-ultraviolet (DUV, 250-450 nm) spectroscopy within a novel cross-band iterative refinement framework. Guided by global and local sensitivity analyses, the strategy systematically isolates coupled parameters: DUV high-frequency interference isolates trench depth, while SWIR wavelength-scale phase shifts determine lateral spacing. By alternating temporary boundary constraints between bands, this iterative feedback loop neutralizes parameter cross-talk and drastically localizes the inverse search space. This approach reduces simulation time by over 90% while actively preventing error propagation. Experimental validation on copper trenches demonstrates excellent agreement with atomic force microscopy, achieving reconstruction errors below 0.65% for both depth and spacing, offering a robust, computationally efficient metrology solution.
Subjects
advanced semiconductor packaging
hybrid metrology
optical critical dimension (ocd)
redistribution layers (rdl)
spectral reflectometry
Publisher
Institute of Physics
Type
journal article