Hybrid Silicon-Oxide Pixel Circuit for Flexible Display Reliability
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Solution Overview
Problem
Existing display apparatuses are vulnerable to external impacts and lack flexibility.
Innovation Solution
A display apparatus design incorporating a substrate with a first silicon-based transistor and a first oxide-based transistor, connected by a bottom metal layer and insulated by multiple inorganic layers, featuring a valley filled with an organic insulating material, and including a storage capacitor with specific electrode configurations to enhance durability and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a silicon-based transistor is used to achieve high switching speed, then the switching speed is improved, but the transistor cannot be operated at 100% duty cycle due to insufficient off-state characteristics
Solution Approach 1:
The patent combines a silicon-based transistor (for high switching speed) and an oxide-based transistor (for excellent off-state characteristics) into a single pixel circuit. The silicon-based transistor serves as the switching element while the oxide-based transistor functions as the hold element, merging the advantages of both material systems to achieve both high switching speed and 100% duty cycle operation capability.
Solution Approach 2:
The invention uses a composite transistor structure where the active channel is formed by an oxide semiconductor layer deposited over a silicon-based semiconductor layer. This composite material structure allows the device to exhibit both the high mobility of silicon (for fast switching) and the excellent off-state characteristics of oxide semiconductors, enabling 100% duty cycle operation.
2Reliability
If an oxide-based transistor is used to achieve high off-state characteristics, then the off-state characteristics are improved, but the transistor cannot be driven at high speed
Solution Approach 1:
The patent combines a silicon-based transistor (for high switching speed) and an oxide-based transistor (for excellent off-state characteristics) into a single pixel circuit. The silicon-based transistor serves as the switching element while the oxide-based transistor functions as the hold element, merging the advantages of both material systems to achieve both high switching speed and 100% duty cycle operation capability.
Solution Approach 2:
The invention uses a composite transistor structure where the active channel is formed by an oxide semiconductor layer deposited over a silicon-based semiconductor layer. This composite material structure allows the device to exhibit both the high mobility of silicon (for fast switching) and the excellent off-state characteristics of oxide semiconductors, enabling 100% duty cycle operation.
3Ease of manufacture
If a bottom-gate transistor structure is used to simplify manufacturing, then the manufacturing process is simplified, but the threshold voltage cannot be adequately controlled
Solution Approach 1:
The patent divides the gate structure into two separate gates: a first gate electrode formed before the semiconductor layer (bottom gate) and a second gate electrode formed after the semiconductor layer (top gate). This segmentation allows independent control and optimization of each gate's function, enabling both simplified manufacturing (using standard bottom-gate processes) and precise threshold voltage control (through top gate adjustment).
Solution Approach 2:
The invention controls the threshold voltage by adjusting parameters of the dual-gate structure, including the gate lengths (L1 and L2), the dielectric layer thickness, and the doping concentrations. By changing these parameters, the threshold voltage can be precisely controlled while maintaining compatibility with standard manufacturing processes.
Data Source
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AI summary
A display apparatus includes a substrate, a first silicon-based transistor including a first semiconductor layer and a first gate electrode. The first semiconductor layer includes a silicon-based semiconductor, and the first gate electrode overlaps the first semiconductor layer, at least one insulating layer on the first gate electrode, a first oxide-based transistor including a semiconductor layer. The semiconductor layer includes an oxide-based semiconductor, a first connection electrode electrically connecting the first semiconductor layer to the semiconductor layer of the first oxide-based transistor, and a bottom metal layer disposed between the substrate and the first silicon-based transistor and overlapping a portion of the first semiconductor layer of the first silicon-based transistor. A portion of the bottom metal layer overlaps a first connection point between a portion of the first semiconductor layer and the first connection electrode.