Semiconductor Shape Measurement Correction via Curvature Equations
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Solution Overview
Problem
Existing methods for measuring the shape of semiconductor patterns struggle to achieve high precision and are not easily applicable to various measurement techniques, and they complicate the correlation of two-dimensional or three-dimensional shapes with shape index values, making it difficult to estimate semiconductor device features and manufacturing process states.
Innovation Solution
A method and apparatus that corrects two-dimensional or three-dimensional shapes by applying a curvature equation based on shape index values, using a graphical user interface to visualize and adjust parameters, allowing for high-precision shape measurement and correlation with semiconductor device features and manufacturing process states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional shape measurement methods are used, then measurement can be performed, but measurement precision is insufficient for high-precision line patterns
Solution Approach 1:
The patent applies feedback by using shape index values calculated from measured shape data to iteratively correct the measured shape. The correction process uses the shape index values as feedback signals to adjust and refine the shape measurement, improving precision by continuously comparing and adjusting against reference values.
Solution Approach 2:
The patent changes parameters by introducing shape index values as additional measurement parameters and using curvature equations with adjustable parameters to correct the measured shape. This allows transformation of the measurement approach from direct geometric measurement to parameter-based correction, achieving higher precision.
2Measurement precision
If shape correction methods are developed for specific measurement techniques, then correction can be applied, but adaptability to different measurement methods is limited
Solution Approach 1:
The patent achieves universality by developing a shape correction method based on shape index values that can be applied to any measurement technique. The method uses general mathematical concepts (curvature equations, shape index calculations) rather than being tied to specific measurement apparatus, making it adaptable to SEM, SPM, and other measurement methods.
Solution Approach 2:
The patent enables broad applicability by transforming the correction approach into a parameter-based system where shape index values and curvature parameters serve as universal intermediaries. This parameter transformation allows the same correction methodology to work across different measurement techniques without requiring method-specific adjustments.
3Measurement precision
If complex correction algorithms are used to improve shape precision, then measurement accuracy increases, but ease of operation decreases
Solution Approach 1:
The patent applies self-service by enabling the measurement system to automatically calculate shape index values and perform corrections using curvature equations without requiring manual intervention. The system self-corrects the measured shape by processing the data through the algorithm, reducing operational complexity while maintaining high precision.
4Loss of information
If correlation methods between shape and device features are established, then device feature estimation becomes possible, but device complexity of the measurement system increases
Solution Approach 1:
The patent uses shape index values as intermediaries to correlate measured shape data with semiconductor device features. Rather than directly analyzing complex device features, the system first computes shape index values that serve as simplified mediators, making the correlation process more manageable while preserving essential information.
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
Enables high-precision two-dimensional or three-dimensional shape measurement and correction, facilitating the estimation of semiconductor device features and manufacturing process states, and allowing for general application across different measurement methods.
Implementation Method 1
exposure of the specimen to electromagnetic wave or electrically charged particles
Implementation Method 2
scanning electron microscopy (hereinafter referred to as "SEM")
Data Source
AI summary
In the past, when a shape was corrected by adjusting parameters of a shape calculating equation proper for a measuring method used in measuring a two-dimensional or three-dimensional shape by correlating the parameters and a shape index value, the degree of freedom of modifying a shape by correction depended on a model equation used in the calculation of the shape, and therefore such a shape correction method was unsuitable for objects of correction having a number of shape variations. According to the present invention, the three-dimensional shape is corrected by fitting a curvature equation to a three-dimensional shape of a semiconductor pattern measured by any three-dimensional shape measuring method and by adjusting parameters of the curvature equation based on a shape index value separately calculated. The relations between the shape index value and the parameters are stored in a data base, and at the time of measurement the measured shapes are corrected based on the relations mentioned above.