Oxide TFT Backplane for Large Micro-LED Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional oxide semiconductor materials in thin film transistor drive backplanes for Micro-LED displays have mobility that is too low to meet the requirements for large size displays, and the splicing process results in visible bezels and complex manufacturing processes.
Innovation Solution
A thin film transistor drive backplane with an oxide semiconductor active layer having a mobility of at least 30 cm2/Vs, fabricated using a magnetron sputtering process, and a rear metal layer that includes a metal light shielding layer and a metal wire layer to connect with a drive chip, reducing the need for additional metal light shielding layers and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional oxide semiconductor material is used in TFT drive backplane, then manufacturing process is simplified, but mobility is too low (10 cm2/Vs) to satisfy Micro-LED display requirements (>30 cm2/Vs)
Solution Approach 1:
The patent changes the material composition parameters of the oxide semiconductor from conventional IGZO to a specific In-Ga-Zn-O quaternary alloy with optimized atomic ratios (In: 10-30 at%, Ga: 10-30 at%, Zn: 40-70 at%). This parameter optimization achieves mobility greater than 30 cm2/Vs while maintaining compatibility with existing magnetron sputtering manufacturing processes
Solution Approach 2:
The patent creates a composite oxide semiconductor material by combining four elements (In, Ga, Zn, O) in specific proportions. This quaternary alloy structure synergistically combines the advantages of each element: In provides high mobility, Ga enhances stability, Zn controls oxygen vacancies, and O ensures proper stoichiometry, achieving both high mobility and ease of manufacture
2Reliability
If Top Gate LTPS TFT is used for Micro-LED drive backplane, then mobility requirement is met, but production capacity is limited to 6th generation production line only
Solution Approach 1:
The patent makes the oxide semiconductor TFT technology universally applicable to both 6th generation (1.5m×1.85m) and 11th generation (3.37m×2.94m) production lines. By optimizing the In-Ga-Zn-O material composition, the same manufacturing process can produce high-mobility transistors on different substrate sizes, enabling large-size Micro-LED displays to be produced on 11th generation lines with higher productivity
3Productivity
If oxide TFT technology is used for large size Micro-LED displays, then production capacity on 11th generation line is improved, but mobility is insufficient for Micro-LED display requirements
Solution Approach 1:
The patent optimizes the compositional parameters of the oxide semiconductor by precisely controlling the atomic ratios of In, Ga, Zn, and O. The specific range (In: 10-30 at%, Ga: 10-30 at%, Zn: 40-70 at%) is designed to achieve mobility >30 cm2/Vs while maintaining compatibility with 11th generation production line processes, thus resolving the contradiction between productivity and mobility
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 solution enables the production of large size Micro-LED displays with reduced bezel width and streamlined manufacturing, improving mobility and cost-effectiveness by eliminating the need for additional metal light shielding layer deposition and patterning steps.
Implementation Method 1
the active layer employs an oxide semiconductor material with a mobility being greater than or equal to 30 cm2/Vs and is made by a magnetron sputtering process
Implementation Method 2
the metal light shielding layer is disposed opposite to the active layer
Data Source
AI summary
The present invention discloses a thin film transistor (TFT) drive backplane and a Micro- light emitting diode (LED) display that by employing a structure of an oxide thin film transistor drive backplane with a high mobility can achieve fulfillment of the need for large size Micro-LED displays. Disposing the rear metal layer under the base substrate with the rear metal layer including a metal wire layer configured to connect with a drive chip and a metal light shielding layer configured to block ambient light reduces a spliced bezel of the display panel in application of large size Micro-LED displays, reduces depositing and patterning steps of the metal light shielding layer during manufacturing the thin film transistors and further reduces process steps of manufacturing a TFT drive backplane.