Thin Film Transistor Light-Shielding Film Simultaneous Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thin film transistors (TFTs) used in active-matrix liquid crystal displays face challenges in achieving high light resistance and reliability while maintaining low manufacturing costs, due to complex processes and increased costs associated with light-shielding and patterning of multiple layers, which lead to light leak currents and poor step coverage.
Innovation Solution
A TFT structure is developed with a light-shielding film, an insulating film, and a semiconductor film made of silicon or silicon-containing materials, where each layer is patterned simultaneously using similar film-forming and etching gases, simplifying the manufacturing process and improving light resistance by reducing light leak currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple light-shielding films and insulating films are provided underneath the semiconductor film, then light resistance is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent combines the light-shielding film and insulating film into a single integrated layer structure underneath the semiconductor film. This merging approach maintains the light-blocking function while reducing the number of separate manufacturing steps, thereby improving light resistance without proportionally increasing manufacturing complexity
Solution Approach 2:
The insulating film is designed to serve dual functions: as an electrical insulator and as a light-shielding layer. By making the insulating film具有光遮蔽功能，the patent eliminates the need for separate light-shielding films, reducing manufacturing steps while maintaining both electrical insulation and light resistance
2Manufacturing precision
If multiple layers are patterned separately, then manufacturing precision is improved, but productivity decreases
Solution Approach 1:
The patent performs simultaneous patterning of multiple layers (light-shielding film, insulating film, and semiconductor film) in a single etching process. This merging of patterning operations maintains manufacturing precision through aligned etching while dramatically improving productivity by eliminating multiple sequential patterning steps
3Reliability
If different materials are used for light-shielding film and insulating film, then functional performance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent uses silicon-based materials for both the light-shielding film and insulating film, creating a homogeneous material system. This allows both layers to be formed using similar deposition processes (such as CVD or sputtering) and patterned using similar etching chemistry, thereby maintaining functional performance while significantly simplifying manufacturing
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 solution achieves high light-resistance characteristics with suppressed light leak currents and reduced manufacturing costs, enhancing the reliability and performance of TFTs in liquid crystal displays.
Implementation Method 1
a light-shielding film formed on an insulating substrate, an insulating film formed on the light-shielding film
Data Source
AI summary
To achieve TFT having a high light-resistance characteristic with a suppressed light leak current at low cost by simplifying the manufacturing processes. The TFT basically includes a light-shielding film formed on a glass substrate that serves as an insulating substrate; an insulating film formed on the light-shielding film; a semiconductor film formed on the insulating film; and a gate insulating film formed on the semiconductor film. Each layer of a laminate that is configured with three layers of the light-shielding film, the insulating film, and the semiconductor film is patterned simultaneously. Further, each layer of the laminate is configured with silicon or a material containing silicon.