Strain-Induced Birefringence in Microlithography Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Microlithographic projection exposure systems face defects in partial beams, particularly polarization variations, which reduce the intensity in preferred state (IPS) and impair imaging quality, especially in the deep ultraviolet wavelength range, leading to increased complexity and cost in manufacturing.
Innovation Solution
The introduction of an optical element with strain-induced birefringence in the illumination system, which compensates for defects by modifying the polarization of partial beams, allowing for effective defect compensation without affecting the beam characteristics, thereby enhancing the IPS and maintaining imaging quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the optical beam is separated into multiple partial beams and guided through various channels, then the imaging quality and process window are improved, but the device complexity increases
Solution Approach 1:
The optical beam is separated into multiple partial beams that travel through different channels, each containing optical elements that can be independently optimized. This segmentation allows for improved imaging quality through better control of polarization and intensity distribution while managing complexity by treating each channel as a modular unit
Solution Approach 2:
Different channels are assigned different optical elements with specific properties tailored to their function. For example, certain channels contain optical elements with strain-induced birefringence to compensate for polarization defects, while others may have different characteristics. This local optimization improves overall imaging quality without requiring all channels to be equally complex
2Illumination intensity
If optical elements are introduced to compensate for polarization defects in channels, then the intensity in preferred state (IPS) is improved, but the device complexity increases
Solution Approach 1:
Instead of attempting to perfectly compensate for all polarization defects across all channels, the invention introduces optical elements with strain-induced birefringence in selected channels where they provide the most benefit. This partial action approach improves the intensity in preferred state sufficiently without requiring every channel to have complex compensation mechanisms
Solution Approach 2:
The invention changes the physical parameters of optical elements by introducing strain to induce birefringence. This parameter change allows the optical elements to modify polarization properties and improve IPS without requiring fundamentally different or more complex device architectures
3Manufacturing precision
If the wavelength is reduced to the deep ultraviolet range, then the resolving power is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The invention operates in the deep ultraviolet wavelength range (193 nm or shorter) to achieve higher resolving power for projecting smaller semiconductor structures. By combining this wavelength parameter change with the introduction of strain-induced birefringence in optical elements, the system maintains manufacturability through controlled polarization compensation rather than requiring entirely new manufacturing approaches
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 solution effectively increases the intensity in preferred state (IPS) of the beam exiting the illumination system, improving imaging quality and reducing the need for complex correction measures, while minimizing the impact on the optical properties of the optical elements.
Implementation Method 1
The at least one optical element is adapted to comprise an arrangement of local persistent modifications which generate a strain induced birefringence
Data Source
AI summary
The invention relates to an illumination system of a microlithographic projection exposure apparatus comprising (a) a plurality of channels, each channel guiding a partial beam and at least one channel comprising at least one defect, and (b) at least one optical element arranged within the at least one channel having the at least one defect, the optical element being adapted to at least partially compensate the at least one defect of the partial beam of the channel.