Nitrogen Doping Gate Insulation Layer LTPS TFT Threshold Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
P-type Thin Film Transistors (TFTs) in display panels exhibit high threshold voltage, leading to splash screens and increased pixel leakage due to high turn-on and turn-off voltages, which are not effectively addressed by existing technologies.
Innovation Solution
A manufacturing method for Low Temperature Poly-silicon (LTPS) TFTs involves nitrogen doping of the gate insulation layer using plasma enhanced chemical vapor deposition, reducing the threshold voltage of P-type TFTs from -1V to -1.3V by increasing positive charges within the gate insulation layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If P-type TFT is used with conventional gate insulation layer, then the TFT can be fabricated with standard process, but the threshold voltage is too high causing splash screen and increased pixel leakage
Solution Approach 1:
The patent applies nitrogen doping to the gate insulation layer, which changes the electrical parameters of the insulation layer by introducing nitrogen atoms. This modifies the charge distribution and interface properties, thereby adjusting the threshold voltage of the P-type TFT from its conventional high value to an optimized range, eliminating splash screen and reducing pixel leakage without requiring process redesign
Solution Approach 2:
The nitrogen doping is applied specifically to the gate insulation layer rather than the entire TFT structure. This localized modification targets the critical interface region where charge accumulation affects threshold voltage, allowing precise control of electrical properties only where needed while maintaining other TFT characteristics
2Device complexity
If high turn-on and turn-off voltages are used in P-type TFT, then the TFT structure remains simple, but energy consumption increases and display quality deteriorates
Solution Approach 1:
By nitrogen doping the gate insulation layer, the patent changes the electrical parameters to reduce turn-on and turn-off voltages. This allows the TFT to operate at lower voltage levels, directly reducing energy consumption during display operation while maintaining the simplicity of the overall device structure
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 method effectively reduces the threshold voltage of P-type TFTs, mitigating splash screen issues and improving energy efficiency by reducing turn-on and turn-off voltages, thereby enhancing the performance of display panels.
Implementation Method 1
depositing a gate insulation layer on the base substrate and applying a nitrogen doping process using nitrogen-containing plasma toward the gate insulation layer
Implementation Method 2
applying a nitrogen doping process using nitrogen-containing plasma toward the gate insulation layer, wherein the gate insulation layer covers the polysilicon active layer
Data Source
AI summary
The present disclosure relates to a manufacturing method of LTPS TFT substrate and the LTPS TFT substrate. With respect to the manufacturing method, after the gate insulation layer is formed, the gate insulation layer is doped with nitrogen by a plasma containing nitrogen so as to increase the positive charges within the gate insulation layer. As such, the P-type TFT threshold voltage can be negatively shifted so as to enhance the splash screen issue.