Hyperspectral Broom Camera Wafer Metrology With Rotational Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical metrology methods for semiconductor manufacturing face challenges in efficiently measuring thin-film thickness, overlay, and wafer-to-wafer bonding overlay with high throughput and accuracy, particularly in characterizing substrates with varying surface conditions and underlying structures.
Innovation Solution
A metrology apparatus and method utilizing a hyperspectral broom camera that rotates and translates a substrate to acquire multi-point optical metrology data, including a handling stage, broadband illumination, and optical detectors to determine thickness distributions based on reflectivity spectra across multiple wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a hyperspectral broom camera is used to acquire multi-point optical metrology data, then measurement precision and characterization accuracy are improved, but device complexity increases
Solution Approach 1:
The substrate is divided into multiple discrete measurement points that are scanned sequentially. The broom camera captures spectra from different locations by rotating the substrate, breaking down the complex task of measuring the entire substrate into manageable segments. This segmentation allows high precision measurements without requiring a complex system that can capture all data simultaneously.
Solution Approach 2:
The system adds rotational movement as an additional dimension to the measurement process. By rotating the substrate on a handling stage, the system transforms a single-point measurement into a multi-point scanning approach, effectively using the rotational degree of freedom to access different measurement locations without increasing the complexity of the optical detection system itself.
2Productivity
If multiple measurement points are acquired by rotating and translating the substrate, then productivity and throughput are improved, but measurement time and process complexity increase
Solution Approach 1:
The substrate rotation and broom camera scanning operate continuously to acquire spectra from multiple measurement points. Rather than stopping between measurements, the system maintains continuous rotational motion and continuous spectral acquisition, maximizing productivity without proportionally increasing total measurement time. The continuous scanning approach ensures that every moment of rotation contributes useful measurement data.
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
Enhances imaging throughput and accuracy by increasing the number of measurement points, allowing for more precise characterization of film thickness, critical dimensions, and overlay measurements with improved sensitivity to substrate features and surface conditions.
Implementation Method 1
obtain a set of reflectivity spectra of a linear region of the substrate via the hyperspectral broom camera
Implementation Method 2
each set of reflectivity spectra includes individual intensities of a plurality of wavelengths of light
Data Source
AI summary
A method of measuring thin-film thickness, overlay, and wafer-to-wafer bonding overlay, including providing a substrate on a handling stage configured for rotation; illuminating the substrate with a broadband illumination beam; obtaining a first set of reflectivity spectra of a first linear region of the substrate via a hyperspectral broom camera; incrementally rotating the substrate by an angle of rotation via the handling stage; obtaining a set of reflectivity spectra of a linear region of the substrate via the hyperspectral broom camera after each incremental rotation; and determining a thickness distribution of the substrate based on sets of reflectivity spectra obtained by the hyperspectral broom camera, wherein each set of reflectivity spectra includes individual intensities of a plurality of wavelengths of light.