Mask Transparent Zone Area Adjustment for Lithography Light Overlap Compensation
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Solution Overview
Problem
In the manufacturing of thin film transistor liquid crystal display (TFT-LCD) substrates, the lithography process is hindered by light overlap regions from multiple lenses in exposure machines, leading to uneven light intensity and lens mura phenomena, which result in variations in photoresist patterns and decreased yield, especially for small-size high-resolution panels.
Innovation Solution
A method and apparatus that adjust the transparent zones in the light overlap region of the mask to compensate for light intensity variations by increasing or decreasing their area relative to the light incident regions, ensuring more accurate exposure patterns by optimizing the light exposure through a mask with specific transparent and non-transparent zones for negative or positive photoresists.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple lenses are used in the exposure machine to increase productivity, then the manufacturing efficiency is improved, but the light intensity becomes uneven in the light overlap region causing lens mura phenomenon
Solution Approach 1:
The patent applies local quality by making the transparent zones in the light overlap region have different areas compared to the light incident region. Specifically, for negative photoresist, the transparent zones in the overlap region are made larger to compensate for insufficient light exposure. This local modification of the mask structure ensures that each region of the mask has the appropriate light transmission properties for its specific function, resolving the uneven light intensity problem while maintaining high productivity from multiple lenses.
2Manufacturing precision
If the light intensity in the light overlap region is adjusted to match the center region, then the photoresist pattern accuracy is improved, but the mask structure becomes more complex
Solution Approach 1:
The patent applies parameter changes by modifying the area parameter of the transparent zones in the light overlap region. Instead of changing the physical structure or adding complex optical components to the mask, the invention simply adjusts the dimensional parameter (area) of the existing transparent zones. This straightforward parameter modification achieves the goal of compensating for light intensity variations while keeping the mask structure relatively simple and easy to manufacture.
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 results in a more accurate exposure pattern on the substrate, reducing the impact of lens-related light intensity variations and improving product yield by aligning the photoresist pattern with the target pattern, thus enhancing the manufacturing efficiency of array and color filter substrates.
Implementation Method 1
exposing the photoresist layer by using a plurality lenses of an exposure machine through a mask
Implementation Method 2
the mask includes a light incident region and a light overlap region, the light overlap region includes a transparent zone and a non-transparent zone
Data Source
AI summary
A method of manufacturing a substrate of a display device is provided. The method includes: providing a substrate body; coating a photoresist layer on the substrate body; exposing the photoresist layer by using a plurality lenses of an exposure machine through a mask, wherein the mask includes a light incident region and a light overlap region, the light overlap region includes a transparent zone and a non-transparent zone, and the light incident region includes a transparent zone and a non-transparent zone, and wherein an area of each transparent zone of the light overlap region is larger or smaller than an area of each transparent zone of the light incident region; and developing the photoresist layer after exposing to obtain a photoresist pattern. The embodiment of the disclosure also provides a mask applied to the method. By practice of the disclosure, the exposure pattern of the light overlap region could be compensated in order to obtain more accurate exposure pattern, so the product yield could be improved.