SiNx Passivation Layout for Stable Display Transistor Characteristics
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Solution Overview
Problem
Existing display devices face challenges in maintaining the characteristics of transistor elements due to hydrogen incorporation during the fabrication process, which affects the reliability and performance of the display.
Innovation Solution
Incorporating a passivation layer made of silicon nitride (SiNx) with a specific hydrogen-to-nitrogen bond ratio of 1:0.6 to 1:1.5, and forming contact holes to directly contact active layers, thereby minimizing hydrogen introduction and stabilizing transistor element characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passivation layer is formed during fabrication, then protection and insulation are improved, but hydrogen incorporation occurs causing transistor element characteristics to change
Solution Approach 1:
The patent utilizes the hydrogen incorporation issue by forming a passivation layer with silicon nitride that has a specific hydrogen-to-nitrogen bond ratio (1:0.6 to 1:1.5). This converts the harmful hydrogen incorporation into a beneficial controlled structure where hydrogen is intentionally included in a specific ratio to passivate interface states and improve transistor characteristics stability.
Solution Approach 2:
The patent changes the chemical composition parameters of the passivation layer by controlling the silicon-to-nitrogen ratio and hydrogen content. Specifically, the passivation layer is formed with a Si:N:H ratio where the number of Si-H bonds to N-H bonds is in a range of about 1:0.6 to 1:1.5, optimizing the electrical characteristics and reducing threshold voltage shifts.
2Ease of manufacture
If conventional passivation layers are used, then fabrication is simplified, but transistor element characteristics change due to hydrogen
Solution Approach 1:
The patent modifies the composition parameters of the passivation layer formed by chemical vapor deposition. The silicon nitride layer is deposited with controlled ratios of silane (SiH4) and nitrogen-containing precursors, achieving a Si:N:H atomic ratio where Si-H to N-H bond ratio is 1:0.6 to 1:1.5, thus improving transistor stability while maintaining fabrication simplicity.
Solution Approach 2:
The passivation layer is formed as a composite structure with silicon nitride as the base material and controlled hydrogen incorporation. This composite approach combines the insulation properties of silicon nitride with the beneficial effects of controlled hydrogen content, creating a multi-functional layer that provides both protection and electrical stability.
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 solution effectively prevents changes in transistor element characteristics, enhancing the reliability and performance of the display device by reducing hydrogen-induced degradation.
Implementation Method 1
a passivation layer disposed on the second conductive layer and the semiconductor layer... a ratio of a number of silicon-hydrogen bonds (Si—H) to a number of nitrogen-hydrogen bonds (N—H) in the silicon nitride (SiNx) is in a range of about 1:0.6 to about 1:1.5
Data Source
AI summary
A display device includes a first conductive layer including a first voltage line and a second voltage line, a buffer layer, a semiconductor layer including a first active layer and a second active layer, a first gate insulating layer, a second conductive layer including a first gate electrode overlapping the first active layer and a second gate electrode overlapping the second active layer, a passivation layer, a via layer, a bank pattern layer including a first bank pattern and a second bank pattern partially spaced apart from each other, a third conductive layer including a first electrode and a second electrode spaced apart from each other, and light emitting elements. The passivation layer includes silicon nitride (SiNx), and a ratio of a number of silicon-hydrogen bonds (Si—H) to a number of nitrogen-hydrogen bonds (N—H) in the silicon nitride (SiNx) is in a range of about 1:0.6 to about 1:1.5.