3D Shape Detection Apparatus Spectral Scatterometry Pattern Interference
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Solution Overview
Problem
In semiconductor manufacturing, spectral scatterometry struggles to accurately manage three-dimensional shape dimensions due to the influence of patterns outside the dimension management target within the field of view during measurement, making it difficult to achieve high accuracy in dimension management.
Innovation Solution
A three-dimensional shape detection apparatus that measures spectral reflection intensity and estimates the area ratio between the target region and the surrounding regions outside the field of view, allowing for the removal of the influence of patterns outside the dimension management target from spectral reflections, enabling accurate dimension management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If spectral scatterometry is performed on actual layout pattern, then measurement accuracy is improved, but influence from surrounding patterns causes measurement error
Solution Approach 1:
The patent divides the measurement field into a target region (first region) and surrounding regions (second region). By separately analyzing the spectral reflection intensity from each region and calculating the area ratio, the influence of surrounding patterns is isolated and removed, enabling accurate dimension management of the target pattern alone.
Solution Approach 2:
The patent extracts the spectral reflection intensity component from the surrounding patterns (second region) from the total spectral reflection measurement. By calculating the area ratio between target and surrounding regions, the harmful influence of surrounding patterns is separated and eliminated from the final dimension management calculation.
2Device complexity
If test element group (TEG) is used in scribe region, then dimension management is simplified, but measurement accuracy deteriorates due to position and pattern density differences
Solution Approach 1:
The patent performs preliminary identification of the target pattern region and calculation of area ratios before conducting the final spectral scatterometry measurement. By pre-separating the target region from surrounding patterns and calculating their area ratios, the subsequent dimension management measurement can focus solely on the target pattern, ensuring high accuracy without requiring TEG in scribe regions.
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 allows for precise dimension management of actual layout patterns by isolating the spectral reflection intensity of the target pattern from surrounding patterns, improving the accuracy of three-dimensional shape detection and management.
Implementation Method 1
spectral scatterometry is performed by measuring spectral reflection intensity of a target with a light spot
Data Source
AI summary
To implement, when a plurality of patterns are included in a field of view during measurement of scattered light in spectral scatterometry, removal of an influence of a pattern outside a dimension (three-dimensional shape) management target from spectral reflection intensity in the field of view without modeling the pattern outside the dimension management target. A three-dimensional shape detection apparatus 100 includes a spectral reflection intensity measurement unit configured to measure spectral reflection intensity in a field of view of a light spot by irradiating a sample 103 as a target with the light spot, and detects a three-dimensional shape in the field of view of the light spot based on the measured spectral reflection intensity. The three-dimensional shape detection apparatus further has a spectral feature value calculation unit configured to calculate a spectral feature value in a first region in the field of view of the light spot in advance in an external control apparatus 102 thereof, and an area ratio estimation unit configured to estimate an area ratio between an area of the first region in the field of view of the light spot and an area of a second region outside the first region in the field of view of the light spot.