GISAXS Misalignment for Sub-Nanometer Metrology
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Solution Overview
Problem
Current GISAXS measurement techniques are complex and time-consuming, particularly when trying to visualize components with sub-nanometric precision, as they require tedious recording and alignment processes to achieve accurate measurements of small-angle X-ray scattering.
Innovation Solution
A method involving a GISAXS technique that misaligns a line array within an X-ray beam, measuring both positive and negative Bragg orders at various angles of incidence to create an asymmetrical diffraction pattern, allowing for more efficient data collection and intensity curve adjustments to determine the profile of periodic patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional GISAXS measurement techniques are used to achieve sub-nanometer precision, then measurement precision is improved, but measurement time and operational complexity increase
Solution Approach 1:
The patent applies asymmetry by deliberately misaligning the line array at a small angle (0.01° to 1°) relative to the X-ray beam incidence plane. This asymmetric configuration causes the diffraction pattern to exhibit asymmetry between positive and negative Bragg orders, enabling differential measurement approaches that reduce measurement time while maintaining sub-nanometer precision through the enhanced sensitivity of asymmetric diffraction patterns to line profile variations
2Measurement precision
If traditional GISAXS measurement techniques are used to achieve accurate measurements, then measurement precision is improved, but operational complexity increases
Solution Approach 1:
By introducing a controlled misalignment angle between the line array and the X-ray incidence plane, the patent transforms the symmetric diffraction pattern into an asymmetric one. This asymmetry simplifies the measurement procedure by creating distinct differences between positive and negative Bragg orders, making it easier to extract line profile information and reducing the complexity of data analysis while maintaining measurement accuracy
3Productivity
If misalignment angle is increased to enhance measurement efficiency, then productivity is improved, but measurement precision may deteriorate
Solution Approach 1:
The patent optimizes the misalignment angle parameter within a specific range (0.01° to 1°) to achieve the best balance between measurement efficiency and precision. By carefully controlling this parameter, the method enhances measurement productivity through asymmetric diffraction patterns while maintaining sufficient precision for sub-nanometer metrology applications
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
This approach doubles the information collected in the same time period, reduces measurement time, and relaxes constraints on angle increments, enhancing the efficiency and precision of microelectronic component metrology.
Implementation Method 1
Measurement method using grazing incidence small angle x-ray scattering; associated instrumental system and computer program product
Implementation Method 2
measuring the quantity on the diffraction pattern obtained for a plurality of Bragg spots
Data Source
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AI summary
This process consists of: placing a grid of lines etched on a sample (10) in an X-ray beam so as to create a misalignment (ϕ) between the grid of lines and a plane of incidence (Pl); illuminating (130) the grid of lines under a given angle of incidence (a); measuring (140) the magnitude on the diffraction pattern obtained for a plurality of Bragg spots, the plurality of Bragg spots comprising one or more positive order Bragg spots and one or more negative order Bragg spots.