Semiconductor Surface Inspection Using 3D Topography Variability
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Solution Overview
Problem
Existing inspection methods for semiconductor surfaces prior to hybrid bonding, such as AFM and conventional optical microscopy, are inefficient due to limited field of view and slow data acquisition rates, failing to detect nanoscale defects effectively.
Innovation Solution
A surface defect inspection system using optical profilometry and statistical analysis of topography data, including phase shift interferometry, to quickly identify and characterize metal pads on semiconductor elements, enabling fast and robust detection of defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If AFM or conventional optical microscopy is used for surface inspection, then measurement precision can be achieved, but productivity is significantly reduced due to limited field of view and slow data acquisition rates
Solution Approach 1:
The patent segments the inspection task into multiple regions of interest (ROIs) across the wafer surface, systematically scanning and analyzing each region separately. This allows comprehensive coverage of large areas while maintaining high measurement precision through focused analysis of individual segments rather than attempting to analyze the entire surface simultaneously.
Solution Approach 2:
The patent transitions from conventional two-dimensional optical microscopy to three-dimensional optical profilometry, adding the height dimension to the inspection process. This enables detection of nanoscale surface defects through topographical analysis, significantly improving measurement precision while the automated scanning approach maintains productivity.
2Ease of operation
If conventional optical microscopy is used, then ease of operation is maintained, but measurement precision is insufficient for detecting nanoscale defects on planarized surfaces
Solution Approach 1:
The patent changes the measurement parameters by using optical profilometry to capture three-dimensional topographical data instead of conventional two-dimensional optical images. This parameter change enables detection of nanoscale height variations and surface defects that are invisible to conventional microscopy, while the automated processing maintains ease of operation.
Solution Approach 2:
The patent replaces conventional optical microscopy with optical profilometry, substituting a mechanical/optical imaging system with a system that measures surface topography through optical interference. This substitution provides the necessary measurement precision for nanoscale defect detection while maintaining operational simplicity through automated data acquisition and analysis.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Facilitates rapid identification of surface defects on semiconductor elements, ensuring high yield in hybrid bonding processes by automating defect detection and reducing inspection time significantly.
Implementation Method 1
A surface defect inspection system using optical profilometry and statistical analysis of topography data, including phase shift interferometry
Data Source
AI summary
A method for surface defect inspection can comprise obtaining topographical data from one or more portions of a semiconductor element. The semiconductor element can have a surface comprising a dielectric and a plurality of metal pads. The method can further comprise processing the topographical data of the one or more portions of the semiconductor element to determine at least a first property of the plurality of metal pads, computing at least one variability value for the first property, and identifying candidate defects in the one or more portions of the semiconductor element based at least in part on the at least one variability value.