Phase Shifting Mask Protrusions for Sub-Resolution Patterning
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Solution Overview
Problem
The high manufacturing cost of liquid crystal display (LCD) apparatus due to the need for high-resolution steppers, which increases exposure efficiency but is costly, necessitates a more efficient method for creating line patterns without significantly raising costs.
Innovation Solution
A mask with a light blocking pattern and a diffraction pattern is used, featuring protrusion parts on a transparent substrate, allowing for increased light exposure and pattern precision without the need for high-resolution steppers, by utilizing a chromium light blocking part and carefully controlled photoresist layer curing to form the diffraction pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a high-resolution stepper is used to reduce line pattern width, then manufacturing precision is improved, but manufacturing cost increases
Solution Approach 1:
A phase shifting mask is introduced as an intermediary component between the light source and photoresist. This mask includes a light blocking pattern with diffracting protrusions that modify the optical path, enabling sub-resolution line patterns to be formed using a lower-resolution stepper, thus avoiding the need for expensive high-resolution steppers
Solution Approach 2:
The invention changes the optical parameters by introducing phase-shifting protrusions on the mask. These protrusions create constructive and destructive interference patterns in the exposed photoresist, allowing line widths smaller than the stepper's native resolution to be achieved, thereby maintaining manufacturing precision while using cost-effective equipment
2Ease of manufacture
If exposure efficiency is increased using a phase shifting mask, then manufacturing cost is reduced, but device complexity increases
Solution Approach 1:
The mask structure is segmented into distinct functional regions: light blocking portions that define the pattern and diffracting protrusions that create the phase-shifting effect. This segmentation allows the complex phase-shifting function to be achieved through simple geometric modifications to the mask structure, making it easier to manufacture despite the enhanced functionality
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 reduces manufacturing costs by enhancing exposure efficiency while maintaining pattern precision, allowing for the creation of narrow line patterns without the expense of high-resolution stepper technology.
Implementation Method 1
The light blocking part is disposed on the transparent substrate and is configured to block light
Implementation Method 2
The diffraction pattern includes a plurality of protrusion parts and is configured to diffract the light
Implementation Method 3
The first photoresist layer is irradiated by a laser beam to cure a first area and a second area
Data Source
AI summary
A mask includes a transparent substrate and a light blocking pattern. The light blocking pattern includes a light blocking part and a diffraction pattern. The light blocking part is disposed on the transparent substrate and is configured to block light. The diffraction pattern includes a plurality of protrusion parts and is configured to diffract the light. The plurality of protrusion parts protrudes from a side of the blocking part and is separated from each other.