Flip-Chip III-Nitride LED Structure with Bragg Reflector
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Solution Overview
Problem
The existing manufacturing methods for flip-chip structures of group III semiconductor light emitting devices require complex and costly processes due to the need for high accuracy in etching holes and the use of multiple metal layers, which increases production costs and complexity.
Innovation Solution
A manufacturing method that uses a linear convex mesa structure instead of multiple holes, with a Bragg reflective layer and multilayer oxide insulation forming a first insulation layer that acts as both a reflector and insulation, eliminating the need for a metal protective layer and simplifying the process by allowing the transparent conductive layer and convex mesa pattern to be formed simultaneously.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal protective layer is used on the back of the highly reflective material to avoid instability, then the reliability is improved, but the device complexity and manufacturing cost increase due to multiple metal layers and complex etching processes
Solution Approach 1:
The patent removes the metal protective layer from the structure. Instead of using multiple metal layers (ITO and Ag or Al), the invention uses a single highly reflective metal layer (Ag or Al) directly contacting the p-type nitride semiconductor layer, eliminating the need for the protective layer while maintaining stability through direct ohmic contact formation
Solution Approach 2:
The highly reflective metal layer serves dual functions: it acts as both the reflective layer and the protective layer simultaneously. By forming an ohmic contact directly between the p-type nitride semiconductor layer and the highly reflective metal layer, the structure eliminates the need for separate protective layers while maintaining both reflectivity and stability
2Manufacturing precision
If high accuracy etching holes is performed to access contact metals, then the manufacturing precision is improved, but the device complexity and production cost increase due to complex etching processes
Solution Approach 1:
The patent removes the complex multi-step etching process for creating holes to access contact metals. Instead of etching holes through multiple layers to reach p-type and n-type contact metals, the invention uses a simplified process where the highly reflective metal layer is deposited and patterned directly, eliminating the need for complex hole etching while maintaining precise electrical contacts
3Reliability
If multiple metal layers are used to form electrodes, then the reliability is improved, but the productivity decreases due to extended manufacturing time and higher production cost
Solution Approach 1:
The patent removes unnecessary metal layers from the electrode structure. Instead of using multiple metal layers (ITO and Ag or Al), the invention uses a single highly reflective metal layer that directly contacts the p-type nitride semiconductor layer, reducing manufacturing steps and increasing productivity while maintaining electrode stability through direct ohmic contact
Solution Approach 2:
The patent combines the functions of multiple metal layers into a single highly reflective metal layer. The highly reflective metal layer simultaneously provides reflectivity, electrical contact, and structural stability, merging what were previously separate functions into one integrated layer, thereby simplifying the manufacturing process and improving productivity
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 method reduces production costs, simplifies the process, and improves the alignment of the transparent conductive layer and convex mesa pattern, while maintaining photoelectric properties and allowing for direct contact between the Bragg reflector and the p-type nitride semiconductor layer, enhancing the structure's reflectivity and insulation.
Implementation Method 1
a first insulation layer structure, which is formed by a Bragg reflective layer, a metal layer and a multilayer of oxide insulation
Data Source
AI summary
This disclosure refers to a manufacturing method of a flip-chip structure of III group semiconductor light emitting device. The manufacturing method includes steps of: growing a substrate, a buffer layer, an N type nitride semiconductor layer, an active layer and a P type nitride semiconductor layer sequentially from bottom to top to form an epitaxial structure, depositing a transparent conductive layer; defining an isolation groove with the yellow light etching process, depositing a first insulation layer structure, depositing a P type contact metal and N type contact metal, depositing a second insulation layer structure, depositing a flip-chip P type electrode and flip-chip N type electrode, then removing the photo resist by using of the stripping process to get a wafer; thinning, dicing, separating, measuring and sorting the wafer. In this disclosure, structure of the first insulation layer structure which is formed by the Prague reflective layer, the metal layer and the multilayer of oxide insulation, acts as a reflector structure and an insulation layer to replace the flip-chip reflector structure design and the first insulation layer, so that a metal protective layer can be omitted.