Lithographic Apparatus Aberration Measurement and Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithographic methods face challenges in achieving high throughput and availability due to time-consuming radiation beam aberration measurements and lens heating effects, which can lead to incorrect image formation on substrates.
Innovation Solution
A method that involves performing radiation beam aberration measurements and adjustments only when necessary, using a lens heating model for intra-lot adjustments, and skipping these steps under certain conditions to increase throughput, while also allowing for feed-forward corrections based on existing lens heating models.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If radiation beam aberration measurement and adjustment are performed for every substrate lot, then image quality and manufacturing precision are maintained, but throughput and productivity decrease due to time-consuming measurements
Solution Approach 1:
The patent performs radiation beam aberration measurements and adjustments in advance before substrate exposure, establishing a baseline state. This preliminary action allows the system to operate without repeated measurements during production, thereby maintaining image quality while improving throughput.
Solution Approach 2:
The patent implements a feedback mechanism that monitors lens heating effects and radiation beam aberrations during substrate exposure. When aberrations exceed predefined thresholds or lens temperature changes are detected, the system automatically triggers adjustments to the projection system, ensuring continuous image quality without requiring frequent full measurements.
2Manufacturing precision
If radiation beam aberration measurement and adjustment are performed frequently, then manufacturing precision is maintained, but loss of time increases due to repeated measurements
Solution Approach 1:
The patent performs comprehensive radiation beam aberration measurements and projection system adjustments as a preliminary action before substrate exposure begins. By establishing the optimal optical state in advance, the system eliminates the need for repeated measurements during production, thereby maintaining pattern accuracy while minimizing time loss.
Solution Approach 2:
The patent implements self-service monitoring where the system automatically detects lens heating effects and radiation beam aberrations during exposure and triggers appropriate adjustments without external intervention. This continuous self-correction maintains pattern accuracy without requiring manual measurement interventions that would cause time loss.
3Productivity
If lens heating effects are not compensated, then measurement and adjustment time is reduced, but manufacturing precision deteriorates due to incorrect image formation
Solution Approach 1:
The patent implements a feedback mechanism that continuously monitors lens temperature and radiation beam aberrations during substrate exposure. When lens heating causes aberration changes that affect image formation accuracy, the system automatically triggers adjustments to the projection system, thereby maintaining manufacturing precision while allowing continuous production without stopping for measurements.
Solution Approach 2:
The patent dynamically changes operational parameters such as projection system alignment and focus settings in response to detected lens heating effects. By adjusting these parameters in real-time based on temperature and aberration monitoring, the system maintains image formation accuracy throughout the production run without requiring interruptions for recalibration.
Data Source
AI summary
A method of patterning substrates using a lithographic apparatus. The method comprising providing a beam of radiation using an illumination system, using a patterning device to impart the radiation beam with a pattern in its cross-section, and using a projection system to project the patterned radiation beam onto target portions of a lot of substrates, wherein the method further comprises performing a radiation beam aberration measurement after projecting the patterned radiation beam onto a subset of the lot of substrates, performing an adjustment of the projection system using the results of the radiation beam aberration measurement, then projecting the patterned radiation beam onto a further subset of the lot of substrates.