Photolithographic Mask Pixel Positioning for Defect Correction
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Solution Overview
Problem
The increasing complexity and cost of manufacturing photolithographic masks with high resolution requirements, coupled with defects such as optical transmission inhomogeneity, registration errors, and overlay errors, necessitate an improved method for correcting errors in photolithographic masks to ensure uniformity and accuracy in semiconductor device production.
Innovation Solution
A method and apparatus using a laser system to determine the positions of pixels to be introduced into a photolithographic mask substrate, considering error data and illumination system parameters, to correct defects like critical dimension errors, registration errors, and overlay errors, by modifying optical transmission and density locally within the mask substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithographic masks are manufactured with higher resolution requirements to meet increasing integration density, then the ability to project smaller structures is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent applies preliminary action by performing defect detection and pixel correction during the mask manufacturing process before the mask is used for wafer fabrication. This allows errors to be identified and corrected in advance, preventing defective masks from proceeding to production, thereby maintaining high resolution requirements while managing manufacturing complexity through early intervention.
2Manufacturing precision
If the exposure wavelength is shifted to the far ultraviolet region (193 nm) to achieve smaller structure projection, then the resolution capability is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent addresses the complexity introduced by far ultraviolet exposure by implementing parameter changes in the mask fabrication process. Specifically, it introduces pixel density and optical transmission corrections as adjustable parameters that can be optimized to compensate for the challenges of 193 nm wavelength exposure, thereby maintaining resolution capability while managing the increased manufacturing complexity through controlled parameter adjustments.
3Manufacturing precision
If pixels are introduced to correct optical transmission inhomogeneity, then the critical dimension uniformity is improved, but the device complexity increases
Solution Approach 1:
The patent applies local quality by introducing pixels with specific optical transmission properties at localized positions within the mask substrate where transmission inhomogeneity is detected. Rather than uniformly modifying the entire mask, the correction is applied locally at specific coordinates determined by error data analysis, thereby improving critical dimension uniformity while minimizing the overall complexity of the correction system.
4Manufacturing precision
If the mask fabrication process is made more complex to achieve high resolution, then the manufacturing precision is improved, but the production time increases
Solution Approach 1:
The patent implements self-service by incorporating automated defect detection and pixel placement determination systems into the mask fabrication process. The system automatically analyzes error data, determines optimal pixel positions and densities, and guides the correction process without requiring extensive manual intervention, thereby maintaining high fabrication precision while reducing the time loss associated with complex manufacturing processes.
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 enhances the defect correction process by optimizing pixel placement based on the specific optical radiation distribution used during the manufacturing process, improving the uniformity and accuracy of pattern elements on wafers, thereby increasing the yield of semiconductor devices.
Implementation Method 1
A method and apparatus using a laser system to determine the positions of pixels to be introduced into a photolithographic mask substrate... by modifying optical transmission and density locally within the mask substrate
Data Source
AI summary
The present invention refers to a method and an apparatus for determining positions of a plurality of pixels to be introduced into a substrate of a photolithographic mask by use of a laser system, wherein the pixels serve to at least partly correct one or more errors of the photolithographic mask. The method comprises the steps: (a) obtaining error data associated with the one or more errors; (b) obtaining first parameters of an illumination system, the first parameters determining an illumination of the photolithographic mask of the illumination system when processing a wafer by illuminating with the illumination system using the photolithographic mask; and (c) determining the positions of the plurality of pixels based on the error data and the first parameters.