Overlapping Pixel Transistors for Dense Stable Data Voltage Routing
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Solution Overview
Problem
Existing display devices face challenges in achieving high pixel integration density and efficient data voltage transmission, which limits their resolution and performance.
Innovation Solution
The display device incorporates a structure where first and second transistors, made of low temperature poly-silicon and oxide semiconductor respectively, overlap with shared electrodes through contact holes on different layers, and includes capacitors to enhance data voltage transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If transistors are arranged in overlapping layers with shared electrodes, then pixel integration density is improved, but device complexity increases
Solution Approach 1:
The patent transitions from planar transistor arrangement to three-dimensional overlapping layers. The first transistor is formed on the substrate while the second transistor is formed on the first gate wiring of the first transistor, creating vertical stacking. This dimensional change allows multiple transistors to occupy the same footprint area, thereby improving pixel integration density without proportionally increasing device complexity.
Solution Approach 2:
The patent merges the electrode structures of the first and second transistors by making them share common electrodes. Specifically, the first lower electrode serves as both the source/drain electrode for the first transistor and the lower electrode for the second transistor. This merging reduces the total number of electrodes required, improving integration density while controlling device complexity.
2Reliability
If oxide semiconductor is used for the second active pattern, then data voltage transmission stability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies different material qualities to different regions: the first active pattern uses low temperature poly-silicon while the second active pattern uses oxide semiconductor. This local differentiation allows the oxide semiconductor to provide superior data voltage transmission stability in the critical second transistor path, while the poly-silicon handles other functions. The selective material application balances performance improvement with manufacturing feasibility.
Data Source
AI summary
A display device includes: a substrate; a first transistor on the substrate; a second transistor on the first transistor and overlapping the first transistor; and an anode electrode on the second transistor and connected to the first transistor, wherein the first transistor includes: a first active pattern on the substrate; and a gate electrode on the first active pattern and overlapping the first active pattern, and wherein the second transistor includes: a first lower electrode on the gate electrode; an upper electrode on the first lower electrode and including a first opening that overlaps the first lower electrode; a second active pattern on the upper electrode and connected to the first lower electrode through the first opening; and a first gate wiring on the second active pattern and overlapping the second active pattern.