Display Substrate Gate-Line Oxide Layer for TFT Short-Circuit Prevention
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Solution Overview
Problem
The yield of display panels is decreased due to short circuits in the overlap region formed by the gate line and the data line during the TFT manufacturing process, resulting from the steep edges and thermal diffusibility of copper in the high-temperature deposition or etching process.
Innovation Solution
A display substrate is designed with an oxide metal layer on the surface of the gate line opposite to the data line, which reduces the possibility of short circuits by providing a high dielectric constant and breakdown voltage, and the manufacturing method involves depositing a first metal film layer including molybdenum, copper, and aluminum metal layers, followed by patterning and oxidation to form an aluminum oxide layer in the opposite region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper metal layer is used in the gate line for high conductivity, then electrical performance is improved, but short circuit risk increases due to thermal diffusibility and steep edges during high-temperature deposition or etching
Solution Approach 1:
An aluminum oxide insulating layer is introduced as an intermediary between the copper gate line and the data line. This mediator prevents direct contact and thermal interaction, eliminating the short circuit risk while preserving the copper's electrical performance. The aluminum oxide layer acts as a protective barrier that isolates the copper from harmful thermal effects during subsequent high-temperature processes.
Solution Approach 2:
The gate line structure is segmented into multiple layers: the copper metal layer for electrical conduction and the aluminum oxide insulating layer for isolation. This segmentation separates the electrical function from the thermal protection function, allowing copper to maintain high conductivity while the aluminum oxide prevents short circuits by creating a physical and thermal barrier.
2Area of stationary object
If the gate line and data line are arranged in overlap region to reduce area, then device integration is improved, but short circuit risk increases due to proximity and thermal interaction
Solution Approach 1:
The aluminum oxide layer serves as a mediator in the overlap region where the gate line and data line are in close proximity. It prevents thermal diffusion from the data line to the copper gate line, eliminating the short circuit risk that would otherwise result from their close arrangement. This enables compact device design without compromising reliability.
Solution Approach 2:
The aluminum oxide insulating layer is applied locally to the gate line in the overlap region where short circuit risk is highest. This localized treatment provides thermal protection precisely where needed, allowing the gate line to maintain its conductive properties elsewhere while preventing short circuits only in the critical overlap area.
3Manufacturing precision
If high-temperature deposition or etching process is used for manufacturing, then manufacturing precision is improved, but short circuit risk increases due to thermal diffusibility of copper
Solution Approach 1:
The aluminum oxide insulating layer is formed beforehand on the copper gate line before subsequent high-temperature deposition or etching processes. This pre-protective layer acts as a cushion against thermal diffusion, preventing the copper from overheating and forming steep edges that could cause short circuits, while allowing the high-temperature processes to proceed for manufacturing precision.
Solution Approach 2:
The aluminum oxide layer serves as a thermal mediator between the external heat source and the copper gate line during high-temperature manufacturing processes. It controls and distributes the thermal energy, preventing localized overheating that would cause copper to diffuse and form short circuits, while still allowing sufficient heat transfer to maintain manufacturing precision.
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
The use of the display substrate with an oxide metal layer effectively reduces the occurrence of short circuits in the overlap region, thereby increasing the yield of display panels by ensuring complete coverage of the overlap region with the oxide metal layer.
Implementation Method 1
forming an oxide metal layer on a surface of an opposite region, opposite to a data line to be formed, of the gate line
Data Source
AI summary
Disclosed are a display substrate and a manufacturing method therefor, and a display device. The display substrate comprises: a substrate base, and an active layer, a gate insulating layer, a first metal film layer, an interlayer insulating layer, a second metal film layer, and a passivation layer stacked in sequence on the substrate base. The first metal film layer comprises a pattern of a gate and a gate line. The second metal film layer comprises a pattern of a source/drain and a data line. The gate line and the data line are partially arranged opposite to each other. An oxide metal layer is provided on the surface of the side of the region of the gate line opposite to the data line facing the data line.