EUV Illumination Configuration Using Mask Phase Wavefront Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in semiconductor manufacturing lies in effectively using EUV light sources for precise patterning due to absorption characteristics, leading to contrast loss and reduced reliability in EUV masks, which affects the quality of semiconductor circuits.
Innovation Solution
A method involving phase measurement of EUV masks, wavefront correction using Zernike polynomials, optimization of a cost function, and configuring an EUV illumination system with optimized EUV light sources to minimize contrast loss and improve patterning accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If EUV light sources are used for precise patterning, then manufacturing precision is improved, but contrast loss occurs due to absorption characteristics
Solution Approach 1:
The patent applies parameter changes by measuring the phase of the EUV mask and using wavefront correction to adjust optical parameters. The cost function optimization modifies illumination parameters to compensate for absorption characteristics, thereby maintaining patterning precision while reducing contrast loss.
Solution Approach 2:
The patent implements feedback through phase measurement of the EUV mask and iterative optimization of the cost function. The measured phase information feeds back into the wavefront correction process, allowing the system to adjust and optimize illumination parameters to minimize contrast loss while maintaining patterning quality.
2Reliability
If wavefront correction is performed to reduce contrast loss, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent achieves universality by implementing a comprehensive cost function that simultaneously optimizes multiple parameters including contrast loss, illumination efficiency, and rotational symmetry. This multi-functional optimization approach consolidates multiple correction objectives into a single unified process, reducing overall system complexity.
Solution Approach 2:
The patent uses parameter changes through cost function optimization to achieve reliable contrast loss reduction. By mathematically optimizing illumination parameters based on measured phase data, the system achieves reliable results without requiring additional physical hardware components, thereby limiting the increase in device complexity.
3Productivity
If multiple EUV light sources are combined to improve illumination efficiency, then productivity is improved, but configuring the system becomes more complex
Solution Approach 1:
The patent applies universality by creating a unified cost function that simultaneously optimizes the configuration of multiple EUV light sources. The optimization process considers illumination efficiency, rotational symmetry, and contrast loss together, allowing the system to configure multiple sources efficiently through a single integrated approach rather than separate optimizations.
Solution Approach 2:
The patent implements feedback by measuring the phase of the EUV mask and using this information to iteratively optimize the configuration of multiple light sources. The cost function optimization uses measured data to adjust source positions and intensities, achieving high illumination efficiency while managing configuration complexity through data-driven optimization.
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 the productivity and reliability of EUV lithography by reducing contrast loss and pattern shift, ensuring high illumination efficiency and rotational symmetry, thereby improving the quality of semiconductor circuit patterns.
Implementation Method 1
an EUV light source, which may include a plasma-based light source or a synchrotron radiation light source
Implementation Method 2
an EUV light source, which may include a plasma-based light source or a synchrotron radiation light source
Implementation Method 3
Due to the absorption characteristics of EUV light, reflective EUV masks may be generally used in an EUV exposure process
Implementation Method 4
the illumination optics for transmitting EUV light to an EUV mask and the projection optics for projecting EUV light reflected by an EUV mask to an exposure target may include a plurality of mirrors
Data Source
AI summary
A method of configuring an extreme ultraviolet (EUV) system may include measuring a phase of an EUV mask, correcting a wavefront based on the phase of the EUV mask, optimizing a cost function, and configuring an EUV illumination system with a combination of EUV light sources based on the optimized cost function.