Oxide Semiconductor Pixel Contact Layout for High Aperture Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In display devices using oxide semiconductors, the reduction in pixel size and wiring width is limited by the arrangement of metal and semiconductor layers, leading to a decrease in aperture ratio due to the need for a metal pedestal between the silicon layer and transparent conductive layer, which reduces the pixel's transparency and electrical contact efficiency.
Innovation Solution
A display device configuration featuring a transistor with an oxide semiconductor layer, a gate electrode, and a gate insulating layer, where a first transparent conductive layer is in contact with the oxide semiconductor layer without overlapping the gate electrode, and a second transparent conductive layer is connected to the first layer while overlapping the gate electrode, eliminating the need for a metal pedestal and enhancing contact efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal pedestal is provided between the silicon layer and the transparent conductive layer in low-temperature polysilicon transistors, then electrical contact is ensured, but the aperture ratio is reduced
Solution Approach 1:
The invention extracts and removes the metal pedestal structure from the transistor configuration. By using an oxide semiconductor layer instead of low-temperature polysilicon, the patent eliminates the need for the metal pedestal that was required to ensure electrical contact in conventional structures, thereby resolving the contradiction between electrical contact integrity and aperture ratio.
Solution Approach 2:
The invention changes the material parameter of the semiconductor layer from low-temperature polysilicon to oxide semiconductor. This material parameter change fundamentally alters the electrical contact characteristics, allowing direct contact between the transparent conductive layer and the semiconductor layer without requiring a metal pedestal, thus improving aperture ratio while maintaining electrical contact integrity.
2Manufacturing precision
If the pixel size and wiring width are reduced, then the display device achieves higher resolution, but the aperture ratio is limited due to the arrangement of metal and semiconductor layers
Solution Approach 1:
The invention removes the metal pedestal structure that occupies space in the pixel arrangement. By eliminating this intermediate structure through the use of oxide semiconductor transistors, the patent allows for more efficient use of pixel area, enabling both high resolution and high aperture ratio to be achieved simultaneously.
3Reliability
If the transparent conductive layer is placed on the metal pedestal, then electrical contact is achieved, but light blockage increases and brightness is reduced
Solution Approach 1:
The invention extracts and removes the metal pedestal structure that causes light blockage. By enabling direct contact between the transparent conductive layer and the oxide semiconductor layer, the patent eliminates the metal layer that would otherwise block light, thereby improving brightness while maintaining electrical contact integrity.
Solution Approach 2:
The invention changes the optical property of the contact structure by removing the metal pedestal. The transition from a metal-based contact structure (which blocks light) to a direct transparent conductive layer-to-oxide semiconductor contact (which allows light transmission) improves the optical characteristics and brightness of the display device.
Data Source
AI summary
A display device includes a first transistor provided with an oxide semiconductor layer, a first gate electrode facing the oxide semiconductor layer and a first gate insulatin layer between the oxide semiconductor layer and the first gate electrode, a first transparent conductive layer in contact with the oxide semiconductor layer in a first contact area not overlapping the first gate electrode in a plan view, and a second transparent conductive layer connected to the first transparent conductive layer in a second contact area overlapping the first gate electrode in a plan view and provided in a display area of the pixel.