Exposure Mask Segmentation for Variable Contact Hole Depth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithographic exposure techniques for display substrates face challenges in efficiently patterning organic insulating layers with different thicknesses, leading to inadequate exposure of the gate layer and resulting defects, which increases production costs and alignment inconsistencies.
Innovation Solution
An exposure mask with distinct transmission and blocking portions is used, allowing for different energy levels of light to be transmitted to form contact holes of varying depths, ensuring sufficient exposure of both the source/drain and gate layers during the same processing step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple exposure techniques are used to pattern the organic insulating layer, then the gate layer can be sufficiently exposed, but production costs increase and alignment inconsistencies are introduced
Solution Approach 1:
The exposure mask is segmented into multiple regions with different light transmission properties: a first region that transmits light at a first energy level for forming contact holes in thinner organic insulating layer portions, and a second region that transmits light at a second energy level for forming contact holes in thicker organic insulating layer portions. This segmentation allows different exposure depths to be achieved in a single exposure process.
Solution Approach 2:
Different regions of the exposure mask are assigned different local qualities in terms of light transmission energy levels. The first region provides lower energy light transmission suitable for thinner areas, while the second region provides higher energy light transmission suitable for thicker areas. This local differentiation enables precise control of exposure depth across varying thicknesses of the organic insulating layer.
2Ease of manufacture
If a single exposure process is used to form contact holes, then production cost is reduced, but the gate layer may not be sufficiently exposed when the organic insulating layer is thicker
Solution Approach 1:
The exposure mask utilizes parameter changes in light transmission energy levels across different regions. By varying the energy level of transmitted light between the first region and second region, the mask enables a single exposure process to achieve different penetration depths, ensuring sufficient exposure of the gate layer even through thicker organic insulating layer portions.
3Manufacturing precision
If multiple exposure masks are used to pattern different depths, then alignment accuracy may be compromised, but deeper exposure is achieved
Solution Approach 1:
The exposure mask merges multiple exposure functions into a single component. By integrating regions with different light transmission energy levels into one mask, the invention eliminates the need for multiple separate exposure masks and processes, thereby maintaining alignment accuracy while achieving variable exposure depths in a single step.
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 defects in the substrate by ensuring proper exposure of the gate layer, even when the organic insulating layer is thicker, while maintaining cost-effectiveness and alignment accuracy.
Implementation Method 1
The first transmission portion is configured to, when illuminated with light, transmit the light at a first energy level. The second transmission portion is configured to, when illuminated with the light, transmit the light at a second energy level.
Data Source
AI summary
An exposure mask includes a first transmission portion, a second transmission portion, and a blocking portion. The first transmission portion is configured to, when illuminated with light, transmit the light at a first energy level. The first transmission portion is disposed in association with formation of a first contact hole in an underlying layer. The second transmission portion is configured to, when illuminated with the light, transmit the light at a second energy level. The second transmission portion is disposed in association with formation of a second contact hole in the underlying layer. The blocking portion is configured to block the light, and is disposed in association with a boundary region between a first region and a second region of the underlying layer. The second transmission portion is further configured to enable the second contact hole to be formed deeper into the underlying layer than the first contact hole.