Metal Oxide TFT Top-Gate Structure for Stable On-State Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transistors using metal oxide as the active layer in display panels suffer from poor stability and low on-state current due to defects at the interface between the active layer and the gate insulating layer, leading to instability and inadequate drive capabilities.
Innovation Solution
A top gate structure is employed with a first gate insulating layer formed through chemical vapor deposition, reducing electron capture phenomena and increasing capacitance between the gate and active layer, while an ohmic contact layer is used to enhance electrical connection between the active layer and the electrode, improving conductivity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If metal oxide is used as the active layer material, then the transistor can be manufactured with lower cost and simpler process, but the stability and on-state current are insufficient
Solution Approach 1:
An ohmic contact layer is introduced as an intermediary between the metal oxide active layer and the electrode. This intermediate layer improves the electrical connection and reduces contact resistance, thereby enhancing the on-state current and stability without changing the active layer material itself. The ohmic contact layer acts as a mediator that bridges the gap between the metal oxide and the electrode, solving the poor electrical connection issue while maintaining the manufacturing advantages of metal oxide.
2Ease of manufacture
If metal oxide is used as the active layer, then the manufacturing process is simplified, but the on-state current is too small for adequate drive capability
Solution Approach 1:
The ohmic contact layer serves as an intermediary that enhances current flow between the electrode and the metal oxide active layer. By improving the contact interface and reducing resistance, this intermediate layer enables higher on-state current while preserving the manufacturing simplicity of using metal oxide as the active layer material.
3Device complexity
If a conventional transistor structure is used with metal oxide active layer, then the device structure is simple, but the threshold voltage drift occurs leading to instability
Solution Approach 1:
The ohmic contact layer is introduced as an intermediary component between the electrode and the metal oxide active layer. This additional layer, while increasing structural complexity slightly, significantly improves threshold voltage stability by reducing interface defects and improving electrical connection, thereby preventing threshold voltage drift and enhancing overall device stability.
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 solution enhances the stability and on-state current of transistors, improving display resolution and performance by reducing threshold voltage drift and increasing current transmission.
Implementation Method 1
A top gate structure is employed with a first gate insulating layer formed through chemical vapor deposition
Implementation Method 2
an ohmic contact layer is used to enhance electrical connection between the active layer and the electrode, improving conductivity and stability
Data Source
AI summary
Provided are an array substrate, a preparation method thereof, a display panel and a display device. The array substrate includes a substrate and at least one transistor located on a side of the substrate. Each transistor of the at least one transistor includes an active layer, a first ohmic contact layer, a first gate and a first electrode. The active layer includes metal oxide. The first ohmic contact layer is in contact connection with a first ohmic contact region of the active layer. The first electrode is electrically connected to the first ohmic contact layer.