Lithographic Patterning Device Error Correction
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Solution Overview
Problem
Current lithographic technologies face challenges in achieving accurate pattern positioning due to errors such as overlay and critical dimension errors, which are not optimally corrected by existing apparatuses, leading to functional issues in devices like semiconductor wafers, and are dependent on specific lithographic apparatuses for correction.
Innovation Solution
A method and system that obtain error information to produce modification information for positional shifts across the patterning device, independent of other layers, to enhance positioning accuracy, using a computer program product and hardware processor system to modify the patterning device based on this information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing lithographic apparatuses are used for pattern positioning, then device manufacturing can proceed, but positioning accuracy is insufficient due to overlay and critical dimension errors
Solution Approach 1:
The patent applies preliminary action by measuring and characterizing positioning errors (overlay and critical dimension errors) before the actual device manufacturing process. Error maps are created in advance to guide subsequent correction steps, allowing the system to pre-compensate for known inaccuracies in the lithographic apparatus.
Solution Approach 2:
The patent implements feedback through metrology processes that measure actual pattern positions and dimensions, compare them against target specifications, and use this information to adjust and correct positioning errors. The measured error data feeds back into the lithographic process to improve subsequent patterning operations.
2Adaptability or versatility
If correction methods dependent on specific lithographic apparatuses are used, then some errors can be corrected, but the solution lacks versatility across different apparatuses
Solution Approach 1:
The patent achieves universality by developing correction methods based on fundamental error characteristics that are independent of specific lithographic apparatus types. The error maps and correction algorithms are designed to be applicable across different lithographic tools, making the solution universally applicable rather than apparatus-specific.
Solution Approach 2:
The patent applies parameter changes by adjusting lithographic process parameters based on measured error data. The system modifies exposure conditions, focus settings, and other controllable parameters to compensate for positioning errors, enabling effective correction across different apparatuses through parameter optimization.
3Manufacturing precision
If overlay-based error correction is used, then relative positioning between layers can be improved, but errors from individual layers cannot be independently corrected
Solution Approach 1:
The patent applies segmentation by separating the error correction process into independent layer-specific measurements and corrections. Instead of treating overlay as a single combined measurement, the system measures and corrects errors for each layer independently, then combines the corrections to achieve both individual and relative positioning accuracy.
Solution Approach 2:
The patent uses intermediary reference measurements and error maps that bridge individual layer measurements with overall overlay correction. These intermediary data structures allow the system to translate individual layer error measurements into coordinated corrections across multiple layers, enabling both independent and relative positioning improvement.
Data Source
AI summary
A method including: obtaining error information indicative of accuracy of positioning a pattern formed on a layer on a substrate relative to a target position, wherein the pattern has been formed by irradiating the layer with a radiation beam patterned by a patterning device; and producing modification information including a map of positional shifts across the patterning device so as to increase the accuracy of positioning the pattern formed using the patterning device modified according to the modification information, the modification information based on the error information, wherein the error information is independent of any other layer on the substrate.