Vertical Thin-Film Transistor Structure for Display Panel Aperture Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thin-film transistor structures with a horizontal channel limit the size of display panels, increasing the volume ratio to pixel structures and decreasing the aperture ratio as pixel sizes shrink.
Innovation Solution
A vertical thin-film transistor structure is fabricated with a substrate, source and drain electrodes stacked vertically, and channel layers extending from the drain electrode to the source electrode, reducing the channel area ratio and volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional bottom gate structure with horizontal channel is used, then the transistor can be easily fabricated, but the area occupied by the transistor increases, reducing the aperture ratio of the pixel structure
Solution Approach 1:
The patent transitions from a planar horizontal channel structure to a vertical channel structure that extends in the thickness direction (z-axis). The channel layers are formed as vertical films connecting source and drain electrodes stacked at different heights, utilizing the third dimension to reduce the footprint area while maintaining channel functionality.
Solution Approach 2:
The patent implements a stacked configuration where the gate electrode, channel layers, source electrode, and drain electrode are arranged in multiple layers vertically. The gate insulation layer nests between the gate electrode and channel layers, while source and drain electrodes are positioned at different vertical levels, creating a compact nested structure that minimizes planar area occupation.
2Volume of stationary object
If the pixel structure volume is reduced to increase aperture ratio, then the aperture ratio improves, but the conventional horizontal transistor structure occupies a larger proportion of the reduced volume
Solution Approach 1:
By transitioning to a vertical channel structure extending in the thickness direction, the transistor components are arranged vertically rather than horizontally. This dimensional change allows the transistor to occupy less planar area and reduces its volume ratio within the pixel structure, enabling higher aperture ratios even as overall pixel volume decreases.
3Ease of manufacture
If the channel is made horizontal as in conventional structures, then the fabrication process is straightforward, but the transistor size limits further miniaturization
Solution Approach 1:
The patent forms channel layers as vertical films extending in the thickness direction between source and drain electrodes positioned at different heights. This vertical orientation reduces the planar footprint and overall transistor dimensions, enabling further miniaturization while maintaining a relatively straightforward fabrication process using standard thin-film deposition and patterning techniques.
Data Source
AI summary
A vertical thin-film transistor structure includes a substrate, a source electrode, an insulation layer, a drain electrode, two first channel layers, a gate insulation layer and a gate electrode, which are stacked upward in that order on the substrate. The first channel layers are respectively disposed at two opposite ends of the drain electrode, and extend from the upper surface of the drain electrode to the upper surface of the source electrode respectively. Each of the first channel layers contacts the source electrode and the drain electrode. The gate insulation layer is disposed on the source electrode, the first channel layers and the drain electrode. The gate electrode is disposed on the gate insulation layer and covers the first channel layers. Therefore, the volume of the conventional thin-film transistor structure shrinks, and the ratio of the volume of the conventional thin-film transistor structure to that of a pixel structure decreases.