Mask Layout Width Limits for Lithography Process Window
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Solution Overview
Problem
In semiconductor manufacturing, integrating patterns with different characteristics into a mask layout narrows the process window, making it challenging for mass production due to strict lithography requirements, especially in 0.13 micron or below processes.
Innovation Solution
A system comprising a mask writer tool, lithography tool, metrology tool, and controller determines a width/space limit for a product mask layout by generating test patterns on a mask and wafer, measuring line and space widths, and establishing a standard exposure dose to broaden the lithography process window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If patterns of different characteristics (dense line/space, isolated line, etc.) are integrated into a mask layout, then the mask layout becomes more complex and functional, but the lithography process window is narrowed down to 0.3 μm which is too strict for mass production
Solution Approach 1:
The patent applies local quality by determining different width/space limits for different pattern types (dense line/space, isolated line, isolated space) rather than using a single universal limit. This allows each pattern type to have optimized lithography parameters, thereby maintaining design flexibility while ensuring reliable manufacturing for each specific pattern configuration.
Solution Approach 2:
The patent introduces dynamic adjustment of width/space limits based on pattern characteristics. The system automatically determines appropriate limits by measuring actual pattern widths from metrology data and comparing them with design values, allowing the lithography process window to be dynamically optimized for each specific mask layout configuration rather than using a fixed strict limit.
2Reliability
If a single width/space limit is used for all pattern types, then the lithography process window is maintained, but the mask layout design flexibility is reduced
Solution Approach 1:
The patent determines different width/space limits for different pattern types (dense line/space, isolated line, isolated space) based on their specific characteristics. This localized approach allows each pattern type to have optimized lithography parameters, maintaining both reliable manufacturing and design flexibility simultaneously.
Solution Approach 2:
The patent changes the width/space limit parameter dynamically based on pattern characteristics. By measuring actual pattern dimensions and comparing with design values, the system adjusts the acceptable width/space limits for different pattern types, thereby maintaining process reliability while enabling diverse mask layout designs.
3Manufacturing precision
If design rules specify strict width/space limits, then manufacturing precision is improved, but the ease of manufacture is reduced due to narrow process window
Solution Approach 1:
The patent implements feedback by measuring actual pattern widths using metrology tools and comparing them with design values. This feedback mechanism allows the system to determine appropriate width/space limits that ensure manufacturing precision while maintaining a feasible process window for mass production. The feedback loop enables continuous optimization of both precision and manufacturability.
Solution Approach 2:
The patent dynamically adjusts width/space limit parameters based on measured pattern dimensions and design specifications. By changing these parameters adaptively rather than using fixed strict limits, the system achieves both high manufacturing precision and ease of manufacture, as the limits are optimized for each specific pattern type and process condition.
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 allows for a broader process window, enabling more flexible and efficient mask layout design by determining optimal width/space limits, thereby improving manufacturing feasibility in semiconductor production.
Implementation Method 1
the lithography tool generates a second pattern on a wafer corresponding to a first pattern on a test mask by a lithography process
Data Source
AI summary
Systems for determining width/space limits for product mask layouts. A mask writer generates a first pattern on a test mask corresponding to a test mask layout. A lithography tool generates a second pattern on a wafer corresponding to a first pattern on a test mask by a lithography process using a preset exposure dose. A metrology tool measures widths of the first and second pattern. A controller determines a width/space limit for the product mask layout according to the width difference between the first and second pattern.