TFT Panel Contact Hole Width Control via Inorganic Passivation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the manufacturing of liquid crystal displays, the formation of contact holes between thin film transistors and field generating electrodes is challenging due to the reflow of organic insulators, which can result in inconsistent and reduced hole sizes, affecting the electrical connectivity and display performance.
Innovation Solution
A thin film transistor array panel design that includes a first passivation layer of inorganic insulating material with a contact hole pattern, preventing the reflow of organic insulating material from a second passivation layer, thereby maintaining a controlled and minimized contact hole width, and ensuring precise electrical connections between electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an organic insulator is used in the insulating layer, then the insulating properties are improved, but the contact hole width becomes inconsistent and may be filled due to reflow
Solution Approach 1:
The insulating layer is segmented into multiple layers: a first insulating layer with an inorganic insulator and a second insulating layer with an organic insulator. This segmentation allows the inorganic layer to provide structural stability for contact hole formation while the organic layer provides superior insulating properties, thereby resolving the contradiction between insulating performance and contact hole dimensional consistency.
Solution Approach 2:
The patent uses a composite insulating structure combining inorganic and organic insulating materials in different layers. The inorganic insulator (such as silicon oxide or silicon nitride) in the first layer provides dimensional stability during processing, while the organic insulator (such as polyimide) in the second layer provides excellent electrical insulation, thus achieving both contact hole width consistency and reliable insulating properties.
2Manufacturing precision
If the contact hole width is minimized for precise electrical connections, then the electrical connectivity is improved, but the contact hole may be filled or become too small due to organic insulator reflow
Solution Approach 1:
The first insulating layer with inorganic material is formed and patterned with a contact hole pattern before forming the second organic insulating layer. This preliminary action creates a structural framework that prevents subsequent organic insulator material from refloving into the contact hole, thereby maintaining precise contact hole dimensions and ensuring reliable electrical connectivity.
Solution Approach 2:
The patent changes the material parameter of the insulating layers, using inorganic insulators with lower reflow tendencies in the first layer and organic insulators with superior electrical properties in the second layer. This parameter change allows minimization of contact hole width for precise electrical connections while preventing hole filling through the use of dimensionally stable inorganic material in the underlying layer.
Data Source
AI summary
A thin film transistor array panel according to an exemplary embodiment of the present invention includes: an insulation substrate; a thin film transistor disposed on the insulation substrate, wherein the thin film transistor includes a first electrode; a first contact hole pattern having a first width, wherein the first contact hole pattern exposes a portion of the first electrode, and a first contact hole to expose the portion of the first electrode, wherein an inner sidewall of the first contact hole pattern constitutes a first portion of the first contact hole.