Compensating Patterning Device Deformation in Lithography
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Solution Overview
Problem
Lithographic projection apparatuses face challenges in accurately projecting design layouts onto substrates due to deformation of patterning devices caused by factors like radiation absorption, temperature changes, and mechanical movements, leading to aberrations and reduced image quality, especially with off-axis illuminations and deep ultraviolet radiation.
Innovation Solution
A method is introduced to determine the deformation of the patterning device and generate a compensatory design layout that accounts for these deformations, ensuring accurate projection by adjusting the design layout to compensate for the patterning device's deformation during exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If off-axis illumination and deep ultraviolet radiation are used to improve resolution, then manufacturing precision is improved, but patterning device deformation increases due to radiation absorption and temperature changes
Solution Approach 1:
The patent applies preliminary action by pre-determining the deformation characteristics of the patterning device before actual pattern projection. A deformation model is created in advance that predicts how the patterning device will deform under specific illumination conditions, allowing compensatory measures to be prepared beforehand rather than reacting to deformation after it occurs.
Solution Approach 2:
The patent implements preliminary anti-action by determining a compensatory design layout that counteracts the predicted deformation effects. The compensatory layout is designed in advance to offset the anticipated patterning device deformation, so that when deformation occurs during exposure, the final projected pattern remains accurate despite the physical changes in the patterning device.
2Manufacturing precision
If compensation methods are applied to maintain pattern accuracy, then manufacturing precision is improved, but device complexity increases due to additional computational and procedural steps
Solution Approach 1:
The patent applies parameter changes by transforming the design layout parameters based on the deformation model. Instead of physically adjusting the patterning device or adding complex real-time correction mechanisms, the solution modifies the numerical parameters of the design layout to pre-compensate for expected deformation, achieving accuracy through computational parameter adjustment rather than physical complexity.
3Manufacturing precision
If real-time deformation monitoring and adjustment are implemented, then manufacturing precision is improved, but productivity decreases due to additional measurement and adjustment time
Solution Approach 1:
The patent eliminates real-time monitoring and adjustment by performing all deformation compensation calculations before pattern projection begins. The deformation model and compensatory design layout are established in advance, allowing the actual exposure process to proceed without interruption for measurement or adjustment, thereby maintaining high productivity while achieving improved pattern fidelity.
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 improves the accuracy of the projected image by compensating for patterning device deformations, enhancing image quality and process windows, and reducing the need for complex adjustments and reworking of masks.
Implementation Method 1
deformation of patterning devices caused by factors like radiation absorption, temperature changes, and mechanical movements
Implementation Method 2
deformation of patterning devices caused by factors like radiation absorption, temperature changes, and mechanical movements
Data Source
AI summary
A method for improving a lithographic process for imaging a design layout onto a substrate using a lithographic projection apparatus comprising a patterning device, wherein the patterning device deforms from a first state to a second state, the method comprising: determining a deformation of the patterning device from the first state to the second state; determining a compensatory design layout from the design layout and the deformation; wherein the compensatory design layout is such that when the compensatory design layout is generated on the patterning device in the first state, the deformation of the patterning device deforms the compensatory design layout to the design layout.