Lithographic Aberration Sensitivity Measurement on Single Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining aberration sensitivity in lithographic processes are slow, inefficient, and potentially inaccurate, often requiring multiple substrates and extensive alignment, which can introduce inaccuracies and inefficiencies in the production process.
Innovation Solution
A method and assembly that control the lithographic apparatus to establish multiple aberration states on a single substrate, allowing pattern features to be applied and measured across different target portions, enabling the determination of aberration sensitivity through controlled changes in aberration states without the need for multiple substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple substrates are used to determine aberration sensitivity, then measurement accuracy can be improved, but the process time and complexity increase significantly
Solution Approach 1:
The invention divides the substrate into multiple target portions (e.g., first target portion, second target portion) that can be processed independently. Each target portion can be exposed under different aberration states, allowing the substrate to serve as multiple test samples simultaneously. This segmentation enables aberration sensitivity measurement across different conditions without requiring separate substrates for each measurement.
Solution Approach 2:
The single substrate is designed to serve multiple functions: it acts as both the test sample and the carrier for pattern features. By incorporating multiple target portions on one substrate, the system achieves multi-functionality where one substrate replaces what would traditionally require multiple separate substrates, reducing overall process complexity and time.
2Reliability
If multiple substrates are used for aberration sensitivity determination, then measurement reliability improves, but device complexity and alignment requirements increase
Solution Approach 1:
The substrate is segmented into multiple target portions that can be independently addressed. This segmentation allows different aberration states to be tested on the same substrate without requiring complex alignment between multiple separate substrates. Each target portion can be processed with controlled aberration states while maintaining a common reference frame on the single substrate.
Solution Approach 2:
Instead of using multiple physical substrates, the invention creates multiple test conditions by varying the aberration state parameter on a single substrate. The different target portions effectively copy the testing function of multiple substrates through software-controlled aberration variations, eliminating the need for physical multi-substrate alignment.
3Measurement precision
If conventional aberration sensitivity methods are used, then measurement accuracy is maintained, but productivity decreases due to extensive processing time
Solution Approach 1:
The invention enables continuous processing by exposing multiple target portions on the same substrate under different aberration states during a single production run. Rather than completing measurements on one substrate before moving to the next, the system continuously varies aberration states and processes multiple target portions in sequence, maintaining productive operation throughout the measurement process.
Solution Approach 2:
The system performs preliminary aberration state variations and measurements on target portions before final production processing. By establishing aberration sensitivity data in advance on the same substrate used for production, the system eliminates the need for separate measurement substrates and integrates measurement into the production flow, improving throughput.
Data Source
AI summary
A lithographic method of determining a sensitivity of a property of a pattern feature to change in optical aberrations of a lithographic apparatus used to provide that pattern feature. The method includes controlling a configuration of the lithographic apparatus to establish a first aberration state, forming a first image of the pattern feature with that lithographic apparatus when the lithographic apparatus is in that first aberration state, measuring a property of the image, controlling a configuration of the lithographic apparatus to establish a second, different, aberration state, forming an image of the same pattern feature with that lithographic apparatus when the lithographic apparatus is in that second aberration state, measuring a same property of the image, and using the measurements to determine the sensitivity of the property of the pattern feature to changes in the aberration state.