Vertical GaN LED Etch Stop Layer for Contact Resistance
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Solution Overview
Problem
The existing methods for manufacturing vertical GaN-based LEDs face challenges in achieving uniformity and preventing damage to the n-type GaN layer during the etching process, leading to increased contact resistance and operating voltage, which degrades luminous efficiency.
Innovation Solution
Incorporating an etch stop layer with different etching selectivity, formed from materials like group III-V, III-VI, or III-VII semiconductor compounds, to selectively expose the n-type GaN layer and prevent damage during etching, while also forming an uneven surface to enhance light emission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the undoped GaN layer and lightly doped n-type GaN layer are removed by etching to expose the n-type GaN layer for electrode contact, then the contact resistance of the n-electrode is reduced and operating voltage is reduced, but the surface of the n-type GaN layer is partially etched and damaged, leading to non-uniform thickness and surface state
Solution Approach 1:
An etch stop layer is formed on the n-type GaN layer before the etching process. This preliminary action protects the n-type GaN layer surface from being etched or damaged during the removal of the undoped and lightly doped GaN layers, ensuring uniform surface state and thickness while still allowing the etching to proceed to expose the n-type GaN layer for electrode contact
Solution Approach 2:
The etch stop layer acts as an intermediary protective layer between the etchant and the n-type GaN layer. It has different etching selectivity compared to the GaN layers, allowing it to be etched selectively to expose the n-type GaN layer while preventing direct etching damage to the GaN layer surface during the process
2Productivity
If the n-type GaN layer surface is damaged during etching, then the etching process can be completed, but the contact resistance and operating voltage increase, resulting in degradation of luminous efficiency
Solution Approach 1:
The etch stop layer is formed in advance on the n-type GaN layer before the etching process begins. This preliminary protective measure ensures that the etching process can be completed successfully to remove the undoped and lightly doped GaN layers, while simultaneously preventing surface damage that would otherwise increase contact resistance and reduce luminous efficiency
Solution Approach 2:
The etch stop layer provides beforehand cushioning or protection to the n-type GaN layer surface. It cushions the surface against the harmful effects of the etching process, preventing etching damage that would lead to increased contact resistance, higher operating voltage, and reduced luminous efficiency
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 stabilizes the contact resistance of the n-electrode, reduces operating voltage, and improves luminous efficiency by preventing n-type GaN layer damage and scattering light emissions.
Implementation Method 1
Incorporating an etch stop layer with different etching selectivity, formed from materials like group III-V, III-VI, or III-VII semiconductor compounds, to selectively expose the n-type GaN layer and prevent damage during etching
Implementation Method 2
forming an uneven surface to enhance light emission efficiency
Data Source
AI summary
A vertical GaN-based LED and a method of manufacturing the same are provided. The vertical GaN-based LED can prevent the damage of an n-type GaN layer contacting an n-type electrode, thereby stably securing the contact resistance of the n-electrode. The vertical GaN-based LED includes: a support layer; a p-electrode formed on the support layer; a p-type GaN layer formed on the p-electrode; an active layer formed on the p-type GaN layer; an n-type GaN layer for an n-type electrode contact, formed on the active layer; an etch stop layer formed on the n-type GaN layer to expose a portion of the n-type GaN layer; and an n-electrode formed on the n-type GaN layer exposed by the etch stop layer.