Light-Concentrating Layer for Amorphous Semiconductor Crystallization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for fabricating thin-film transistor (TFT) substrates are complex and inefficient, particularly in forming polycrystalline semiconductor layers for improved charge mobility and ON current in liquid crystal displays.
Innovation Solution
A method involving the formation of a gate electrode, insulating film, amorphous semiconductor pattern, and light-concentrating layer with protrusions on the TFT substrate, where light is irradiated to crystallize the amorphous semiconductor pattern, focusing energy onto the channel region for efficient crystallization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polycrystalline semiconductor layer is formed through conventional methods, then charge mobility and ON current are improved, but fabrication process becomes complicated
Solution Approach 1:
The patent changes the physical state parameter of the semiconductor layer from amorphous to crystalline through controlled laser irradiation. By adjusting laser parameters (energy density, scanning speed, number of passes) and using a light-concentrating layer to modify light distribution, the amorphous semiconductor is transformed into polycrystalline form, achieving high charge mobility through a simplified single-step process rather than multiple conventional fabrication steps
Solution Approach 2:
The light-concentrating layer acts as an intermediary component that focuses and concentrates laser energy onto the amorphous semiconductor layer. This intermediary structure enables efficient energy transfer and controlled crystallization, allowing the laser processing to achieve polycrystalline formation without requiring complex multi-step fabrication processes
2Productivity
If conventional laser processing is used without light concentration, then higher energy laser beams are required, but processing speed decreases and energy consumption increases
Solution Approach 1:
The light-concentrating layer utilizes curved or lens-like structures to focus parallel laser beams into concentrated energy points on the semiconductor layer. This geometric concentration of light energy allows lower-power lasers to achieve the same crystallization effect that would require high-energy beams without focusing, thereby increasing processing speed and reducing energy consumption
Solution Approach 2:
The invention introduces a spatial dimension of light concentration by adding the light-concentrating layer at an intermediate position between the laser source and the semiconductor. This dimensional addition allows energy to be concentrated at a specific focal point rather than being distributed over a large area, enabling efficient processing with lower energy input
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 simplifies the fabrication process, increases crystallization efficiency, and allows for the use of lower energy laser beams, enhancing processing speed and efficiency while maintaining defect-free transistor formation on larger substrates.
Implementation Method 1
The protrusion focuses the light onto the exposed portion of the amorphous semiconductor
Implementation Method 2
crystallizing at least part of the amorphous semiconductor pattern by irradiating the protrusion with light
Data Source
AI summary
A method of fabricating a thin-film transistor (TFT) substrate includes forming a gate electrode on a substrate; forming an insulating film on the gate electrode; forming an amorphous semiconductor pattern on the insulating film; and forming a source electrode separated from a drain electrode on the amorphous semiconductor pattern; forming a light-concentrating layer, which includes a protrusion, on the amorphous semiconductor pattern, the source electrode, and the drain electrode; and crystallizing at least part of the amorphous semiconductor pattern by irradiating light to the protrusion of the light-concentrating layer.