Oxide Semiconductor Target Joints for Display Luminance Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of display units with oxide semiconductor TFTs faces challenges in luminance unevenness due to particle issues at the joints of divided ITO targets, leading to variations in electrical characteristics and luminance variations in organic EL displays.
Innovation Solution
A method of forming an oxide semiconductor layer using a sputtering method with a target having divided portions jointed in a planar form, where the spacing interval between joints is equal to or less than the width of the luminance distribution orthogonal to the joints, ensuring uniform luminance by minimizing local variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a divided target is used for sputtering oxide semiconductor layer, then large-sized substrate can be processed, but luminance unevenness occurs due to particle issues at joints
Solution Approach 1:
The target is divided into multiple segments that can be independently adjusted or replaced. This allows optimization of each segment's properties and easy replacement of defective segments without replacing the entire large target, thereby maintaining luminance uniformity while processing large substrates
Solution Approach 2:
Different regions of the target are designed with locally optimized properties. The joint regions are specifically treated to minimize particle generation, and the spacing between joints is controlled to ensure that luminance distributions from adjacent joints overlap and cancel out unevenness
2Area of stationary object
If target joints are placed closer to increase target area, then larger substrate coverage is achieved, but particle generation increases at joints
Solution Approach 1:
The harmful particle generation at joints is converted into a beneficial effect by strategically positioning joints such that their luminance distributions overlap and cancel out luminance unevenness. The joint regions are designed to generate controlled luminance variations that compensate for display region non-uniformities
3Object-generated harmful factors
If spacing between joints is increased to reduce particle issues, then particle generation is reduced, but luminance distribution becomes non-uniform
Solution Approach 1:
The spacing between joints is precisely controlled within a specific range that balances particle generation reduction with luminance uniformity. By optimizing this geometric parameter, the luminance distributions from adjacent joints overlap appropriately to cancel unevenness while maintaining acceptable particle generation levels
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 reduces luminance unevenness and enhances display quality by achieving uniform light emission across the display region, improving the yield and cost-effectiveness of oxide semiconductor targets.
Implementation Method 1
A sputtering method is typically used for the formation of an oxide semiconductor layer
Data Source
AI summary
A method of manufacturing a display unit includes: forming, on a substrate, a thin-film transistor having an oxide semiconductor layer; and forming, above the thin-film transistor, a display region that includes a plurality of display elements. The oxide semiconductor layer is formed using a sputtering method in which a target and the substrate are opposed to each other. The target is made of an oxide semiconductor and includes a plurality of divided portions that are jointed in a planar form. A spacing interval between two joints that are formed by the plurality of divided portions and are side-by-side with one another of the target is equal to or less than a width of a luminance distribution arising in the display region in a direction substantially orthogonal to the joints.