Flare Map Calculation for Lithography Overexposure Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional photolithography methods using multiple reticles for semiconductor device manufacturing fail to accurately account for the overexposure effects caused by neighboring die patterns, leading to inaccurate resist feature sizes, especially in extreme ultraviolet (EUV) lithography, where 'dark' area reflections cannot be ignored.
Innovation Solution
A method involving a computing apparatus that generates a modified layout file by copying features from neighboring die locations into a flare map calculation area, allowing for a comprehensive flare map calculation that includes the patterning effects of adjacent die, thereby replicating the flare map to cover the entire exposure field and perform optical proximity correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional flare map calculation is used considering only subject die location patterning, then calculation complexity is reduced, but manufacturing precision deteriorates due to inaccurate overexposure estimation
Solution Approach 1:
The exposure field is divided into multiple regions: subject die location, neighboring die locations, and kerf regions. The flare map calculation is segmented to process each region separately, copying features from neighboring die into the subject die's flare map calculation area. This segmentation allows accurate inclusion of overlapping exposure effects while managing calculation complexity through systematic regional processing.
Solution Approach 2:
Features from neighboring die locations are copied into the flare map calculation area before performing the flare map calculation. This preliminary action ensures that the overexposure effects from neighboring die are already accounted for in the calculation, enabling accurate pattern formation without requiring complex real-time calculations during exposure.
2Manufacturing precision
If multiple reticles are used for patterning, then manufacturing precision is improved for small pitch patterns, but device complexity increases
Solution Approach 1:
Instead of using multiple physical reticles, the invention copies features from neighboring die locations into the layout file for the subject die location. This creates a modified layout that includes all features that will be exposed in the subject die's field, including overlapping exposures from neighboring die. This copying approach eliminates the need for multiple reticles while maintaining pattern accuracy.
Solution Approach 2:
A single reticle is designed to perform multiple functions: patterning the subject die and accounting for overlapping exposures from neighboring die. By incorporating copied features from neighboring die into the subject die's layout, the single reticle achieves what previously required multiple specialized reticles, reducing device complexity while maintaining manufacturing precision.
3Productivity
If exposure field size is made larger than stepping distance, then productivity is improved, but manufacturing precision deteriorates due to overexposure from neighboring die
Solution Approach 1:
The invention implements a feedback mechanism where the flare map calculation for the subject die location incorporates information about neighboring die patterns. By copying features from neighboring die and calculating their contribution to overexposure, the system receives feedback about the actual exposure conditions, enabling accurate compensation and precise resist feature formation despite larger exposure fields.
Solution Approach 2:
The invention changes the parameters used in flare map calculation by including features from neighboring die locations in the calculation area. This parameter change transforms the calculation from considering only subject die patterning to considering combined patterning effects, enabling accurate overexposure compensation that maintains manufacturing precision while allowing larger exposure fields for improved productivity.
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 pattern accuracy and yield in semiconductor devices by accounting for the overlapping exposures from neighboring die patterns, ensuring more precise feature formation and improved performance in photolithography processes.
Implementation Method 1
Light is then transmitted through the reticle onto a thin layer of material called photoresist previously added to the wafer. The chrome blocks the light while the glass allows it to pass.
Data Source
AI summary
A method includes receiving a layout file for a reticle used to pattern a first die location in a computing apparatus, the layout file defining a plurality of kerf features. A flare map calculation area for the first die location covering at least a portion of a kerf region surrounding the first die location is defined in the computing apparatus. Features in the layout file into the region corresponding to the flare map calculation area that are associated with the patterning of die locations neighboring the first die location are copied in the computing apparatus to generate a modified layout file. A flare map of the portion of the kerf region included in the flare map calculation area based on the modified layout file is calculated in the computing apparatus.