LTPO Display Substrate Layout for Uniform Via Hole Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display substrates face challenges in yield due to non-uniform critical dimensions and abnormal slope angles caused by different etching depths of via holes in LTPO technology, which combines LTPS and metal oxide semiconductor layers.
Innovation Solution
The display substrate design includes a first active layer and a second active layer made of different materials, both in the same layer and same material, allowing for a uniform etching process of via holes, ensuring consistent etching depths and improving yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different etching depths are used for via holes in LTPS and metal oxide semiconductor layers, then the etching process can accommodate different material requirements, but the critical dimensions become non-uniform and slope angles become abnormal
Solution Approach 1:
The patent merges the etching processes for LTPS and metal oxide semiconductor layers into a single unified etching step. By designing the via hole structure to penetrate both layers simultaneously with consistent etching parameters, the patent achieves uniform critical dimensions and slope angles while maintaining compatibility with different material properties through optimized via hole geometry and positioning.
2Reliability
If separate etching processes are used for LTPS and metal oxide semiconductor layers, then material-specific requirements are met, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent combines multiple etching operations into one unified etching process that handles both LTPS and metal oxide semiconductor layers. This is achieved through careful design of the via hole structure, etching selectivity, and process parameters, thereby reducing manufacturing steps, lowering costs, and simplifying the overall patterning process while maintaining material-specific performance requirements.
3Reliability
If via holes are etched to different depths for different layers, then layer-specific electrical properties are optimized, but the yield of the display substrate decreases
Solution Approach 1:
The patent implements a unified etching approach where via holes penetrate both LTPS and metal oxide semiconductor layers in a single process step. This consolidation eliminates variability associated with multiple etching steps, ensures consistent electrical properties across different layers, and significantly improves substrate yield by reducing process-induced defects and non-uniformities.
Data Source
AI summary
The present application provides a display substrate, a method for manufacturing the same, and a display device, which belongs to the technical field of displays. The display substrate includes: a base substrate and a plurality of sub-pixels on the base substrate, the sub-pixels include a sub-pixel driving circuit and a light-emitting element. The sub-pixel driving circuit includes: a first transistor and a second transistor; an active layer structure of the first transistor includes a first active layer and a second active layer connected to the first active layer. The second active layer is located at a side of the first active layer away from the base substrate, the first active layer includes a first active portion and a second active portion which are independent from each other, and the first active portion and the second active portion are connected to two ends of the second active layer, respectively.