Driving Substrate TFT Layout for Higher Mobility in Compact Displays
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Solution Overview
Problem
The improvement of electron mobility in thin film transistors is limited, and increasing the channel width of thin film transistors leads to an increase in transistor size, which is not conducive to achieving high-resolution displays.
Innovation Solution
A driving substrate design with a source electrode, drain electrode, and active layer, where the channel length is defined by the space between the electrodes, and additional auxiliary electrodes and conductive layers are used to enhance electron mobility without increasing transistor size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the width of the channel region of the thin film transistor is increased to improve electron mobility, then the electron mobility is improved, but the size of the entirety of the thin film transistor increases
Solution Approach 1:
The gate electrode is extended to overlap with the source and drain regions in addition to covering the channel region, creating a three-dimensional electric field distribution. This dimensional extension allows the gate to control carrier flow more effectively without requiring a wider channel, thus improving electron mobility while maintaining compact transistor size
Solution Approach 2:
The invention changes the geometric parameters of the gate electrode, making its length longer than the channel length to create overlap regions with source and drain. This parameter modification enables enhanced electric field control and improved electron mobility without increasing the overall transistor footprint
2Reliability
If the material of the active layer is changed to improve electron mobility, then the electron mobility is improved, but the manufacturing complexity increases
Solution Approach 1:
Instead of changing the active layer material, the invention changes the structural parameters of the gate electrode (making it longer than the channel to create overlap), providing an alternative pathway to improve electron mobility while avoiding the complexity of material substitution and associated manufacturing process changes
Data Source
AI summary
A driving substrate includes a substrate, a source electrode, a drain electrode, an active layer, and a gate electrode. The source electrode and the drain electrode are disposed on the substrate. There is a first space between the source electrode and the drain electrode. The active layer is disposed on the substrate, the source electrode, and the drain electrode, and includes a channel, a source region, and a drain region. The source region covers at least part of the source electrode. The drain region covers at least part of the drain electrode. The channel corresponds to the first space. The gate electrode is disposed on a side of the active layer away from the source electrode and the drain electrode, and is disposed corresponding to the active layer. A method is used for fabricating the driving substrate. A display panel includes the driving substrate.