Semiconductor Light Shielding Layer for Display Device Transistor Protection
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Solution Overview
Problem
Existing flat panel display devices face issues with light leakage due to incident light affecting the transistor's channel region, leading to image quality degradation, and the use of metallic light shielding materials can damage transistors and complicate manufacturing processes.
Innovation Solution
A display device with a light shielding layer made of semiconductor material, such as amorphous or poly-silicon, is integrated beneath the transistor, sharing the same etched surface as the semiconductor layer, to prevent light leakage and simplify manufacturing by eliminating the need for additional mask processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metallic light shielding layer is used, then light shielding effect is improved, but transistor damage occurs and manufacturing complexity increases
Solution Approach 1:
The patent changes the material parameter of the light shielding layer from metallic to semiconductor material. This parameter change maintains the light shielding function while eliminating the harmful effects of metallic materials such as static electricity generation and thermal conductivity that cause transistor damage.
Solution Approach 2:
The light shielding layer is formed using the same semiconductor material as the transistor's semiconductor layer, creating material homogeneity. This eliminates the interface between dissimilar materials (metal and semiconductor) that causes reliability issues, while still providing effective light shielding.
2Object-affected harmful factors
If a separate metallic light shielding layer is added, then light shielding effect is improved, but manufacturing process complexity increases
Solution Approach 1:
The patent merges the light shielding layer formation with the existing semiconductor layer formation process. By forming both layers from the same semiconductor material using the same deposition and crystallization processes, the need for separate metallic layer deposition and additional masking steps is eliminated, simplifying the manufacturing process.
Solution Approach 2:
The semiconductor material serves multiple functions: it forms the active transistor channel layer and simultaneously forms the light shielding layer. This multi-functionality eliminates the need for dedicated light shielding materials and processes, reducing overall manufacturing complexity.
3Object-affected harmful factors
If metallic light shielding material is used, then light shielding effect is improved, but thermal and electrical damage to transistor occurs
Solution Approach 1:
The patent changes the physical parameters of the light shielding layer by using semiconductor material instead of metallic material. This changes the thermal conductivity and electrical conductivity parameters to lower values, preventing heat and electricity generation that would damage the transistor, while maintaining light absorption properties.
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
The semiconductor-based light shielding layer effectively absorbs incident light, reducing photo leakage current and improving image quality while preventing transistor damage and simplifying the manufacturing process by using non-metallic materials with lower thermal and electrical conductivity.
Implementation Method 1
The semiconductor material may be poly-silicon. Alternatively, the semiconductor material may be amorphous silicon... effectively absorbs incident light, reducing photo leakage current
Data Source
AI summary
A display device capable of implementing the light shielding effect and process simplification, and a method of manufacturing the display device. The display device includes a transistor formed in a first region on a substrate, a pixel electrode formed in a second region on the substrate, a buffer layer formed beneath the transistor in the first region, and a light shielding layer formed between the buffer layer and the substrate in the first region. In the display device, the light shielding layer may include a semiconductor material.