Oxide Semiconductor Transistor Light Blocking Layer
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Solution Overview
Problem
Existing liquid crystal display panels do not effectively block light from above the semiconductor layer, leading to variations in transistor characteristics due to photoelectric conversion effects, which can cause abnormalities.
Innovation Solution
A transistor configuration with a light blocking layer made of metal, electrically connected to the upper gate electrode, is implemented on a substrate, ensuring the oxide semiconductor layer is entirely overlapped by the light blocking layer to prevent light incidence, and the source and drain electrodes are connected through conductor contact holes in the insulating films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a light-blocking film is added below the semiconductor layer, then light from below is blocked, but light from above the semiconductor layer is not blocked causing photoelectric conversion abnormalities
Solution Approach 1:
The light blocking function is segmented into two separate locations: a light-blocking film below the semiconductor layer and a light blocking layer above the oxide semiconductor layer. This segmentation ensures that light is blocked from both directions, preventing photoelectric conversion abnormalities while maintaining transistor characteristic stability.
Solution Approach 2:
The light blocking approach is extended from one dimension (below the layer) to another dimension (above the layer). By adding the light blocking layer in the opposite direction, the patent achieves comprehensive light blocking without affecting transistor performance.
2Object-affected harmful factors
If a light blocking layer is added above the oxide semiconductor layer, then light incidence is blocked, but device complexity increases
Solution Approach 1:
The light blocking layer is integrated with existing transistor structures such as gate electrodes or planarization layers, allowing it to serve multiple functions: light blocking, electrical conduction, and structural planarization. This reduces the need for separate dedicated light blocking structures.
Solution Approach 2:
The light blocking layer is merged with other transistor components (gate electrodes, planarization layers) to combine multiple functions into a single structure, thereby reducing overall device complexity while achieving effective light blocking.
3Reliability
If the light blocking layer is electrically connected to the upper gate electrode, then floating electrode formation is prevented, but manufacturing precision requirements increase
Solution Approach 1:
The light blocking layer is designed to overlap with the gate electrode in plan view, creating a preliminary alignment that ensures electrical connection through the gate contact hole. This preliminary positioning simplifies the manufacturing process by reducing the precision requirements for subsequent alignment steps.
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
This configuration effectively blocks light incident on the oxide semiconductor layer, stabilizing transistor characteristics and preventing the formation of floating electrodes by maintaining the same potential as the upper gate electrode, thus ensuring stable operation.
Implementation Method 1
a light blocking layer layered on the second insulating film and formed of metal... the oxide semiconductor layer is configured such that a region overlapping with the upper gate electrode entirely overlaps with the light blocking layer
Data Source
AI summary
The transistor includes a first insulating film, an oxide semiconductor layer, a gate insulating film, an upper gate electrode, and a second insulating film being sequentially layered on a substrate, and the transistor includes a light blocking layer layered on the second insulating film and formed of metal. The light blocking layer is electrically connected to the upper gate electrode by interposing a gate contact hole provided in the second insulating film. The oxide semiconductor layer is configured such that a region overlapping with the upper gate electrode entirely overlaps with the light blocking layer.