AMOLED Manufacturing Reducing Photo-Masks via Self-Aligned Gate Metal
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Solution Overview
Problem
The complexity and cost of manufacturing LTPS TFT OLED panels are increased due to the need for multiple photo-masks in the photolithograph etching process, leading to misalignment and decreased yield.
Innovation Solution
A method that reduces the number of photo-masks required by altering the metal line position, omitting the inter-layer dielectric and passivation layers, and using a buffer insulator layer, while maintaining the gate metal on the metal layer to prevent shorting, and employing a spin-on glass process for the pixel define layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If seven photo-masks are used to complete the OLED manufacturing process, then the manufacturing process can be completed according to traditional methods, but the process complexity increases and manufacturing cost increases
Solution Approach 1:
The patent merges the functions of multiple photo-masks into fewer steps by using self-aligned processes. Specifically, the gate metal layer serves as a self-aligned mask for subsequent etching steps, eliminating the need for separate photo-masking steps that would otherwise be required to define the gate electrode and associated structures. This integration reduces the total photo-mask count from seven to six while maintaining complete process functionality.
Solution Approach 2:
The gate metal layer is assigned multiple functions: it serves as both the functional gate electrode and as a self-aligned mask for defining the source/drain regions and other structures. This multi-functionality reduces the need for dedicated mask layers, thereby simplifying the overall photolithography process and reducing the number of photo-masks required.
2Reliability
If seven photo-masks are used in the photolithograph etching process, then all necessary structures can be defined, but the manufacturing cost increases
Solution Approach 1:
The patent combines multiple structuring functions into fewer photolithography steps. By using the gate metal layer as a self-aligned mask, the patent eliminates the need for separate photo-masks to define gate-related structures, thereby reducing the photo-mask count from seven to six and lowering manufacturing costs while maintaining complete structure definition.
Solution Approach 2:
The gate metal layer serves itself as a mask for subsequent etching operations. Instead of requiring external photo-masks to define the source/drain regions and other gate-associated structures, the gate metal layer's own physical presence provides the necessary masking function, thereby reducing process steps and cost.
3Reliability
If seven photo-masks are used for manufacturing OLED, then all layers can be properly formed, but misalignment increases and yield decreases
Solution Approach 1:
The patent merges the gate electrode formation and gate mask definition into a single self-aligned process. The gate metal layer is deposited and patterned first, then automatically serves as the mask for subsequent etching steps. This self-alignment eliminates cumulative alignment errors that would occur with multiple separate photo-masking steps, thereby improving manufacturing precision and yield while maintaining complete layer formation.
Solution Approach 2:
The gate metal layer is formed and positioned in advance before serving as a mask for subsequent structures. This preliminary positioning establishes a fixed reference that ensures precise alignment for all subsequent etching steps, eliminating alignment drift that would occur with multiple independent photo-masking operations.
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
Simplifies the manufacturing process, decreases costs, and improves yield by reducing the number of photo-masks needed from seven to six, while maintaining panel functionality and allowing for various emission types by adjusting metal and electrode positions.
Implementation Method 1
The amorphous silicon film then re-crystallizes to polycrystalline silicon after an excimer laser annealing (ELA) process.
Implementation Method 2
The amorphous silicon film then re-crystallizes to polycrystalline silicon after an excimer laser annealing (ELA) process.
Implementation Method 3
performing an ion doping to form a source and a drain
Data Source
AI summary
The present invention relates to a method of manufacturing an AMOLED panel. The method comprises providing a substrate, forming a data line and a drain metal on the substrate, forming a buffer insulator layer, forming an active layer, forming a gate insulator layer, forming a gate metal, performing an ion doping to form a source and a drain, forming a via hole, forming a transparent electrode and a pixel define layer, and forming a LED on the transparent electrode.