Vertical GaN LED n-type Gradient Buffer Ion Implantation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing fabrication methods for vertical GaN-based LED chips face challenges with high contact resistance and thermal resistance due to the difficulty in controlling the etching of the u-doped buffer layer, which affects luminous efficiency and the service life of the components, especially in ultra-high power applications.
Innovation Solution
The introduction of an n-type gradient buffer layer formed through ion implantation, which allows for high-concentration doping without impeding subsequent epitaxial growth, enabling direct electrode contact to the surface layer and reducing thermal resistance by eliminating the need for etching the u-doped buffer layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the u-doped buffer layer is etched to expose the n-GaN layer for electrode contact, then the electrode can be formed, but the etching process is difficult to control and results in high contact resistance and high thermal resistance
Solution Approach 1:
The invention removes the u-doped buffer layer entirely from the structure and replaces it with an n-type buffer layer that extends through to the n-GaN layer. This extraction of the problematic u-doped layer eliminates the need for difficult etching processes while maintaining good electrical contact and thermal conduction properties.
Solution Approach 2:
The invention changes the doping type parameter of the buffer layer from undoped (u-type) to n-type, creating an n-type buffer layer that provides both mechanical support and electrical conduction. This parameter change eliminates the need for etching while achieving low contact resistance and low thermal resistance simultaneously.
2Temperature
If the u-doped buffer layer is etched to reduce thermal resistance, then heat dissipation improves, but the etching difficulty and contact resistance problems persist
Solution Approach 1:
The u-doped buffer layer is extracted and replaced with an n-type buffer layer that provides inherent thermal conduction pathways from the n-GaN layer to the substrate, eliminating thermal resistance issues without requiring precise etching operations.
Solution Approach 2:
Changing the buffer layer doping from undoped to n-type creates a continuous conductive pathway for both electricity and heat, simultaneously improving electrical contact and thermal conduction while avoiding etching-related precision problems.
3Reliability
If high-concentration doping is applied to reduce contact resistance, then electrical contact improves, but subsequent epitaxial growth may be impeded
Solution Approach 1:
The n-type buffer layer is designed with a doping concentration gradient, having higher doping concentration near the substrate for good electrical contact and lower doping concentration near the n-GaN layer to facilitate epitaxial growth. This local quality variation simultaneously achieves low contact resistance and growth compatibility.
Solution Approach 2:
The doping concentration parameter is optimized to provide sufficient electrical conduction while remaining compatible with subsequent epitaxial growth processes, resolving the contradiction between contact resistance reduction and growth facilitation.
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 significantly improves the component characteristics of vertical LED chips by reducing thermal resistance and enhancing luminous efficiency, leading to improved performance and extended service life, especially in high-power applications.
Implementation Method 1
changing the buffer layer into an n-type gradient buffer layer through ion implantation
Implementation Method 2
forming an n-type cladding layer via the second epitaxial growth on the n-type gradient buffer layer
Data Source
AI summary
Disclosed is a light-emitting diode with an n-type graded buffer layer and a manufacturing method therefor. An epitaxial structure of a light-emitting diode comprises: a growth substrate; an n-type graded buffer layer located on the growth substrate; an n-type limiting layer (231) located on the n-type graded buffer layer; an active layer (232) located on the n-type limiting layer (231); and a p-type limiting layer (233) located on the active layer (232). A buffer layer is converted into an n-type graded buffer layer by means of an ion implantation method, and is applied to a light-emitting diode chip of a vertical structure while ensuring that a high-quality epitaxial structure is obtained, thereby being able to effectively reduce the contact resistance.