Multi-Gate TFT Layout Under Wiring for Higher Display Aperture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing active matrix display devices face challenges in increasing aperture ratio without adding manufacturing steps, and complex opening shapes in electroluminescent (EL) display devices promote shrinkage of light-emitting portions, while semiconductor devices require larger element areas.
Innovation Solution
The display device incorporates a thin film transistor (TFT) with a channel formation region under a wiring, where the channel width direction is parallel to the current flow direction, and employs a multi-gate structure with increased channel width and length to enhance aperture ratio without complex opening shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a material with a high dielectric constant is used for a capacitor to increase the aperture ratio, then the aperture ratio is improved, but the number of manufacturing steps increases
Solution Approach 1:
The patent changes the geometric parameters of the capacitor (increasing area, changing shape) rather than changing the dielectric material properties. By modifying the capacitor's physical dimensions and configuration, the aperture ratio is improved without introducing additional manufacturing steps for new materials.
2Area of stationary object
If the area of an opening is increased to increase the aperture ratio, then the aperture ratio is improved, but the shape of the opening becomes complex
Solution Approach 1:
The patent utilizes the vertical dimension by positioning the channel formation region under the wiring in the third dimension (below the substrate surface), rather than expanding the opening area in the planar view. This allows the opening to maintain a simple shape while still achieving increased aperture ratio through the multi-dimensional arrangement of components.
3Area of stationary object
If the shape of an opening is made complex to increase the area of the opening, then the aperture ratio is improved, but the length of the edge of the opening increases
Solution Approach 1:
The patent resolves this contradiction by moving the channel formation region to a position under the wiring, utilizing the vertical dimension. This allows the opening to have a simple shape with shorter edges while still achieving the required aperture ratio through the three-dimensional arrangement of the TFT and wiring structures.
4Area of stationary object
If the channel width direction of the channel formation region is made parallel to the current flow direction, then the aperture ratio is improved, but the device layout becomes more constrained
Solution Approach 1:
The patent positions the channel formation region under the wiring, utilizing the vertical dimension to accommodate the parallel arrangement of channel width direction and current flow direction. This three-dimensional configuration allows the aperture ratio to be improved without creating layout constraints in the planar view, as the components are stacked vertically rather than arranged horizontally.
Data Source
AI summary
An object is to provide a display device with a high aperture ratio or a semiconductor device in which the area of an element is large. A channel formation region of a TFT with a multi-gate structure is provided under a wiring that is provided between adjacent pixel electrodes (or electrodes of an element). In addition, a channel width direction of each of a plurality of channel formation regions is parallel to a longitudinal direction of the pixel electrode. In addition, when a channel width is longer than a channel length, the area of the channel formation region can be increased.