SiOxNy Capping Structure for Color Conversion Substrate Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices face reliability issues due to penetration of foreign materials into the low refractive index layer, leading to defects and reduced performance.
Innovation Solution
A color conversion substrate is designed with a capping layer made of silicon oxynitride (SiOxNy) having specific nitrogen and oxygen content ranges, along with a taper angle of 90 degrees or less for the bank side surface, to form a strong Si—N—H bond, reducing void spaces and preventing material penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional capping layer is used, then the manufacturing process is simple, but foreign materials penetrate into the low refractive index layer causing defects
Solution Approach 1:
The capping layer is divided into multiple sub-layers with different materials and functions: a first capping layer (SiOxNy with 10-35 at% nitrogen) providing adhesion and void space reduction, a second capping layer (SiOxNy with 0.2-5 at% nitrogen) providing oxidation resistance, and an organic capping layer providing planarization. This segmentation allows each layer to address specific reliability issues without requiring excessive complexity in a single layer.
Solution Approach 2:
The patent employs a composite capping layer structure combining inorganic materials (silicon oxynitride with controlled nitrogen content) and organic materials. This composite approach leverages the advantages of each material type: inorganic layers provide barrier properties and adhesion, while organic layers provide planarization and protection, collectively preventing foreign material penetration more effectively than a single material could.
2Reliability
If the bank side surface has a large taper angle, then the manufacturing process is easier, but void spaces increase allowing material penetration
Solution Approach 1:
The patent specifies a precise parameter range for the taper angle of the bank side surface (90 degrees or less). By controlling this geometric parameter within a defined range, the structure achieves optimal balance between manufacturing feasibility and preventing void space formation that would allow material penetration. This parameter control is implemented through controlled deposition or etching processes.
3Reliability
If the nitrogen content in silicon oxynitride is increased, then the Si—N—H bond formation improves reducing void spaces, but the oxidation resistance may be affected
Solution Approach 1:
The capping layer is segmented into two silicon oxynitride layers with different nitrogen content: the first layer (10-35 at% nitrogen) optimized for Si—N—H bond formation and void space reduction, and the second layer (0.2-5 at% nitrogen) optimized for oxidation resistance. This segmentation allows each layer to be optimized for its specific function without compromising the other.
Solution Approach 2:
Different regions of the capping layer structure have different nitrogen content tailored to local requirements: the lower layer (first capping layer) has higher nitrogen content to reduce void spaces and improve adhesion to the low refractive index layer, while the upper layer (second capping layer) has lower nitrogen content to provide superior oxidation resistance. This local quality variation optimizes overall performance.
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 enhances the reliability of the display device by minimizing defects and improving luminance, transmittance, and oxidation resistance, while maintaining the existing characteristics of the display device.
Implementation Method 1
form a strong Si—N—H bond
Implementation Method 2
The color conversion layer may convert a wavelength of light provided from the display substrate
Data Source
AI summary
A color conversion substrate includes a base substrate, a color filter layer on the base substrate, a low refractive index layer on the color filter layer, a capping layer on the low refractive index layer, where the capping layer includes a first capping film including silicon oxynitride (SiOxNy) having a nitrogen content in a range of about 10 at % to about 35 at %, a bank on the capping layer, where an opening defining a plurality of pixels is defined in the bank, and a color conversion layer on the capping layer in the opening.