Array Substrate Drive Transistor Threshold Voltage Consistency
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Solution Overview
Problem
Current array substrates exhibit inconsistent threshold voltages between drive and switch transistors due to the presence of a light-shielding layer between the drive transistor and the substrate but not between the switch transistor and the substrate, affecting display quality.
Innovation Solution
A method is proposed to produce an array substrate by forming a preset layer with different carrier concentrations for the drive and switch active layers, where the carrier concentration in the drive active layer is set to be less than that in the switch active layer, using sublayers of indium gallium zinc oxide and indium zinc oxide, and adjusting their thickness and material composition to achieve consistent threshold voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a light-shielding layer is provided between the drive transistor and substrate but not between the switch transistor and substrate, then the drive transistor characteristics are protected from light irradiation, but the threshold voltages of drive and switch transistors become inconsistent
Solution Approach 1:
The patent applies local quality by creating different carrier concentrations in different regions of the active layer. The drive transistor region has a lower carrier concentration (1×10^18 to 5×10^18 cm^-3) compared to the switch transistor region (5×10^18 to 1×10^19 cm^-3), which compensates for the light-shielding layer effect and achieves threshold voltage consistency between the two transistor types.
Solution Approach 2:
The patent changes the carrier concentration parameter in the active layer to resolve the threshold voltage inconsistency. By controlling the carrier concentration through material composition (In-Ga-Zn-O with specific Ga ratios) and thickness variations in different regions, the threshold voltages of drive and switch transistors are made consistent despite the presence of the light-shielding layer.
2Manufacturing precision
If the carrier concentration in the drive active layer is reduced to compensate for the light-shielding layer, then the threshold voltage consistency is improved, but the drive transistor current drive capability may be reduced
Solution Approach 1:
The patent optimizes the carrier concentration parameter to a specific range (1×10^18 to 5×10^18 cm^-3) in the drive transistor region that balances threshold voltage consistency with adequate current drive capability. This parameter optimization ensures that the drive transistor can still drive the liquid crystal effectively while maintaining consistent threshold voltage with the switch transistor.
Solution Approach 2:
The patent uses composite In-Ga-Zn-O semiconductor materials with specific composition ratios to achieve the desired carrier concentration range. By controlling the Ga ratio and material composition, the active layer provides both the required electrical characteristics for threshold voltage consistency and sufficient current drive capability for liquid crystal operation.
Data Source
AI summary
This disclosure discloses an array substrate, and a production method, a display panel, and a display apparatus thereof. Particularly, this disclosure proposes a method of producing an array substrate, having the following steps: providing a substrate having a drive transistor region and a switch transistor region thereon; forming an preset layer for active layer on a side of the substrate; patterning the preset layer for active layer to form a drive active layer and a switch active layer, wherein an orthographic projection of the drive active layer on the substrate is located in the drive transistor region, an orthographic projection of the switch active layer on the substrate is located in the switch transistor region, and a carrier concentration in the drive active layer is less than a carrier concentration in the switch active layer.