Silicon Nitride Buffer Layer for GIP Oxide TFT Hydrogen Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydrogen inflow into an oxide thin film transistor in the gate in panel (GIP) area of electroluminescent display devices causes degradation of transistor characteristics and reliability.
Innovation Solution
A buffer layer made of silicon nitride is formed in the GIP area to block hydrogen diffusion from the encapsulation layer into the oxide thin film transistor, preventing damage and maintaining transistor performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an oxide thin film transistor is used in the GIP area, then manufacturing cost is reduced and manufacturing precision is improved, but hydrogen diffusion from the encapsulation layer degrades transistor characteristics and reliability
Solution Approach 1:
A buffer layer made of silicon nitride is introduced between the oxide thin film transistor and the encapsulation layer. This intermediary layer blocks hydrogen diffusion from the encapsulation layer to the transistor, preventing degradation while maintaining the benefits of using oxide thin film transistors in the GIP area.
Solution Approach 2:
The encapsulation structure is segmented by adding a separate buffer layer component. Instead of relying on a single encapsulation layer, the structure is divided into an outer encapsulation layer and an inner buffer layer, where each layer performs a specific function: the encapsulation layer provides overall protection while the buffer layer specifically blocks hydrogen diffusion.
2Reliability
If a buffer layer is added to block hydrogen diffusion, then transistor reliability is improved, but device complexity increases
Solution Approach 1:
The buffer layer is applied locally only in the GIP area where oxide thin film transistors are positioned, rather than covering the entire display device. This localized approach provides the necessary hydrogen barrier function where needed while minimizing the increase in overall device complexity and maintaining manufacturing efficiency.
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 silicon nitride buffer layer enhances the reliability and characteristics of the thin film transistor by preventing hydrogen diffusion, thereby reducing defects such as white stripes and improving yield.
Implementation Method 1
a buffer layer disposed on the passivation layer or the planarization layer in the GIP area and made of silicon nitride... block diffusion of external hydrogen or hydrogen in the encapsulation layer into the oxide thin film transistor therebelow
Data Source
AI summary
An electroluminescent display device according to an exemplary embodiment of the present disclosure may include a substrate including an active area and a non-active area having a gate in panel (GIP) area outside the active area, an oxide thin film transistor disposed on the substrate in the GIP area, a passivation layer disposed on the oxide thin film transistor, a planarization layer disposed on the passivation layer, a buffer layer disposed on the passivation layer or the planarization layer in the GIP area and made of silicon nitride and a light emitting element disposed on the planarization layer and including an anode, a light emitting unit, and a cathode. As a result, by preventing hydrogen inflow into an oxide thin film transistor, characteristics and reliability of the thin film transistor can be improved.