LTPS Substrate Amorphous Silicon Light Shielding Hydrogen Explosion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high production costs and complexity in fabricating LTPS substrates due to the need for opaque metal light shielding layers, which require additional processing steps, and the occurrence of hydrogen explosion defects during the excimer laser annealing (ELA) process.
Innovation Solution
A LTPS substrate with a light shielding layer composed of amorphous silicon doped with a lanthanide element, such as cerium, which reduces processing steps and prevents hydrogen explosion by effectively fixing residual hydrogen, using a doping treatment with controlled kinetic energy to ensure the lanthanide element does not interfere with the polysilicon layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an opaque metal light shielding layer is used, then light shielding efficiency is improved, but device complexity and production cost increase due to additional mask formation processes
Solution Approach 1:
The patent changes the material parameters of the light shielding layer from opaque metal to amorphous silicon with controlled optical properties. By adjusting the thickness and composition of the amorphous silicon layer, the light shielding efficiency is maintained while eliminating the need for additional mask formation processes, thus reducing device complexity
Solution Approach 2:
The patent uses a composite structure combining amorphous silicon light shielding layer with ITO transparent conductive layer. This composite material approach allows the light shielding layer to provide both optical shielding and electrical functionality, replacing the traditional metal layer that required separate mask processes
2Object-affected harmful factors
If an opaque metal light shielding layer is used, then light shielding efficiency is improved, but production cost increases due to additional mask formation processes
Solution Approach 1:
By changing from metal material to amorphous silicon material and adjusting layer thickness parameters, the patent eliminates the need for expensive mask formation processes while maintaining light shielding efficiency, thereby reducing production cost
Solution Approach 2:
The patent extracts and removes the mask formation process from the manufacturing sequence by using amorphous silicon that can be deposited directly as the light shielding layer, eliminating the need for separate metal layer deposition and mask alignment steps
3Object-affected harmful factors
If conventional light shielding layer is used, then light shielding is achieved, but hydrogen explosion defects occur during excimer laser annealing process
Solution Approach 1:
The patent converts the harmful effect of residual hydrogen in amorphous silicon by introducing lanthanide elements that have high affinity for hydrogen. The lanthanide atoms capture and bind the residual hydrogen atoms, preventing them from accumulating and causing hydrogen explosion during ELA processing, while the amorphous silicon layer continues to provide effective light shielding
Solution Approach 2:
The lanthanide element acts as an intermediary between the amorphous silicon matrix and residual hydrogen atoms. It mediates the interaction by providing binding sites for hydrogen, effectively removing the harmful hydrogen from the system before ELA processing occurs
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
This approach ensures light shielding efficiency while reducing production costs and preventing ELA defects, simplifying the fabrication process and enhancing the stability of the thin film transistor and display device.
Implementation Method 1
Since the lanthanide element has a strong hydrogen (H) bonding capacity, it can react rapidly with H, and it can be rapidly bonded with H to form dihydride or trihydride
Implementation Method 2
During the ELA process
Implementation Method 3
the occurrence of hydrogen explosion defects during the excimer laser annealing (ELA) process
Implementation Method 4
employing ion implantation where kinetic energy of the lanthanide element ion is controlled such that the lanthanide element ion enters a position where the light shielding layer is located
Data Source
AI summary
The present disclosure provides a field of display technologies, and in particular, to a LTPS substrate and a fabricating method thereof, a thin film transistor thereof, an array substrate thereof, and a display device thereof. The LTPS substrate, able to be used for the fabrication of a thin film transistor, includes a light shielding layer, the light shielding layer mainly composed of amorphous silicon doped with a lanthanide element. The present disclosure mainly employs an amorphous silicon film layer doped with the lanthanide element as the light shielding layer of the LTPS substrate, which not only ensures the light shielding efficiency but also reduces the production process, and further prevents the occurrence of the H explosion problem due to H exuding during the ELA process.