Pinhole Masking Layer in LEDs for Dislocation Blocking
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Solution Overview
Problem
Current light emitting diode (LED) technologies face challenges in achieving optimal performance due to the propagation of dislocations from the substrate into the active region, which degrades the quality of the LED, particularly when using patterned sapphire substrates with lattice mismatches.
Innovation Solution
A dielectric masking layer with pinholes is introduced, having a thickness of 20 nm or less and pinhole widths of 200 nm or less, which allows the n-doped semiconductor material to fill and contact the buffer layer, thereby terminating dislocations and improving the quality of the active region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a patterned sapphire substrate is used with lattice mismatches, then the substrate provides structural support, but dislocations propagate from the substrate into the active region degrading LED quality
Solution Approach 1:
A dielectric masking layer with pinholes is introduced as an intermediary between the patterned sapphire substrate and the n-doped semiconductor layer. This masking layer acts as a mediator that allows selective contact while blocking dislocation propagation, thus protecting the active region from substrate defects while maintaining structural support.
Solution Approach 2:
The dielectric masking layer is designed with localized pinholes rather than being completely continuous or completely porous. This creates local quality variation where the masking layer is insulating in most areas but conductive at specific pinhole locations, enabling selective electrical contact while maintaining overall dislocation blocking functionality.
2Reliability
If a dielectric masking layer is introduced to terminate dislocations, then LED quality is improved, but the device structure becomes more complex
Solution Approach 1:
The dielectric masking layer is designed with a porous structure containing pinholes rather than being completely solid. This porous design allows the layer to maintain its dielectric and dislocation-blocking properties while providing localized pathways for electrical contact, eliminating the need for additional complex patterning steps.
3Reliability
If the dielectric masking layer thickness is reduced to 20 nm or less, then dislocation termination is improved, but manufacturing precision requirements increase
Solution Approach 1:
The thickness of the dielectric masking layer is optimized to 20 nm or less, representing a specific parameter change that balances dislocation termination effectiveness with manufacturing feasibility. This thin thickness provides sufficient dislocation blocking while remaining compatible with standard thin-film deposition processes.
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 effectively terminates dislocations at the dielectric masking layer, reducing their propagation into the n-doped semiconductor layer and enhancing the overall quality and performance of the light emitting diode.
Implementation Method 1
forming a n-doped semiconductor material layer on the dielectric masking layer such that the n-doped semiconductor material of the n-doped semiconductor layer fills the pinholes and contacts the buffer layer
Implementation Method 2
This approach effectively terminates dislocations at the dielectric masking layer, reducing their propagation into the n-doped semiconductor layer and enhancing the overall quality and performance of the light emitting diode
Data Source
AI summary
A structure includes a first material layer, a second material layer, and a dielectric masking layer having a thickness of 20 nm or less and containing pinholes having a width of 200 nm or less filled with the second material of second material layer located between the first material layer and the second material layer. A method of forming a LED includes forming a buffer layer over a support substrate, forming a dielectric masking layer having a thickness of 20 nm or less and containing pinholes having a width of 200 nm or less on the semiconductor buffer layer, forming a n-doped semiconductor material layer on the dielectric masking layer such that the n-doped semiconductor material of the n-doped semiconductor layer fills the pinholes and contacts the buffer layer, forming an active region over the n-doped semiconductor material layer, and forming a p-doped semiconductor material layer over the active region.