Mask Pattern Disposing Method for Semiconductor Exposure Alignment
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Solution Overview
Problem
In semiconductor manufacturing, the accuracy of pattern engagement during the exposure step is compromised by mask movement variations and light diffraction, leading to inefficiencies in the development process due to incomplete patterns and alignment issues.
Innovation Solution
A pattern disposing method and exposing method where geometric patterns on a mask are arranged in odd and even columns with selective pattern placement, allowing for partial overlap between edge columns to ensure complete pattern engagement and alignment, even with errors, and reducing the need for incomplete pattern engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If patterns are arranged in all columns including edge columns, then pattern completeness is improved, but alignment accuracy deteriorates due to movement variations and diffraction
Solution Approach 1:
The pattern array is segmented into odd columns and even columns with different arrangements. Edge columns are further segmented to have fewer patterns compared to internal columns. This segmentation allows the system to maintain pattern completeness in internal columns while reducing alignment sensitivity at edge columns, thereby resolving the contradiction between quantity and precision.
Solution Approach 2:
Different column positions are assigned different pattern densities: internal columns have full pattern arrangements for completeness, while edge columns have reduced pattern arrangements for alignment stability. This local differentiation in pattern density allows the system to optimize both pattern completeness and alignment accuracy in different spatial locations simultaneously.
2Quantity of substance
If multiple exposure steps are performed to complete patterns, then pattern completeness is improved, but production efficiency deteriorates
Solution Approach 1:
The mask is pre-configured with selectively arranged patterns in edge columns before exposure. This preliminary arrangement ensures that during the exposure process, patterns can be completed in fewer steps because the edge columns already have the appropriate pattern density to avoid incomplete engagements. This eliminates the need for additional exposure steps, thereby maintaining both pattern completeness and production efficiency.
3Quantity of substance
If edge columns have full pattern arrangements, then pattern completeness is improved, but engagement accuracy deteriorates due to diffraction and movement
Solution Approach 1:
The mask design introduces asymmetry between edge columns and internal columns. Edge columns have fewer patterns arranged differently compared to the full arrangements in internal columns. This asymmetric design reduces the impact of diffraction and movement variations at the edges, thereby improving engagement accuracy while maintaining overall pattern completeness through the full arrangements in internal columns.
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 ensures smooth engagement of exposed patterns, maintains pattern completeness, and minimizes rounding issues, enhancing the accuracy and efficiency of the semiconductor manufacturing process.
Implementation Method 1
the diffraction of the light might affect the accuracy of the engagement
Implementation Method 2
a mask is used for blocking some energy light to project on a photoresister layer, such that the photoresister layer can be developed some pattern
Data Source
AI summary
A mask, a pattern disposing method thereof and an exposing method thereof are provided. A plurality of geometric patterns are arranged on the mask along a plurality of columns. The arrangement of the patterns arranged along odd columns is similar to that of the patterns arranged along even columns. Two odd columns or two even columns are selected to be a first edge column and a second edge column respectively. At each corresponding position of the first edge column and the second edge column, only one of the first edge column and the second edge column is selected to be disposed one geometric pattern.