GaN Light Emitting Device Convex Insulating Layer
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Solution Overview
Problem
Nitride semiconductor light emitting devices face reduced light emitting efficiency due to total reflection and damage from dry etching during n-type electrode formation, which affects optical and current-voltage characteristics.
Innovation Solution
A nitride semiconductor light emitting device with a structured insulating member having a predetermined pattern, such as a trapezoid, is used to reflect light and minimize damage by employing wet etching for electrode formation, enhancing light emitting efficiency and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flat insulating layer is used, then the device structure is simple, but total reflection occurs at the interface reducing light emitting efficiency
Solution Approach 1:
The patent applies curvature by forming the insulating layer with a convex upward surface instead of a flat surface. This convex shape has a maximum height positioned between the first and second cladding layers, creating a curved interface that reduces total reflection of light generated in the active layer, thereby improving light emitting efficiency while maintaining manufacturing simplicity through a single-layer structure.
2Productivity
If dry etching is used to form the n-type electrode, then the electrode formation process is efficient, but the nitride semiconductor layer is damaged reducing optical and electrical characteristics
Solution Approach 1:
The patent changes the etching parameter from dry etching to wet etching for forming the n-type electrode. This parameter change eliminates damage to the nitride semiconductor layer that occurs with dry etching, preserving the optical and electrical characteristics of the semiconductor while still achieving efficient electrode formation through the wet etching process.
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 structured insulating member effectively reduces total reflection and minimizes semiconductor layer damage, significantly improving light emitting efficiency and maintaining device reliability.
Implementation Method 1
When light is incident from a material with an optically large refractive index to a material with a small refractive index, if an incident angle is greater than a predetermined angle (critical angle), the light is totally reflected on the interface.
Implementation Method 2
the light emitted from the active layer moves along light paths, and the light path is caused by such a total reflection
Data Source
AI summary
A semiconductor light emitting device having a light emitting structure including at least one first conductive GaN based semiconductor layer, an active layer above the at least one first conductive GaN based semiconductor layer, and at least one second conductive GaN based semiconductor layer above the active layer, a plurality of patterns disposed from the at least one second conductive GaN based semiconductor layer through a portion of the at least one first conductive GaN based semiconductor layer, and an insulating member on the plurality of patterns. The plurality of patterns include a lower part contacting with the light emitting structure and a upper part contacting with the light emitting structure. A first base angle of the lower part is different from the second base angle of the upper part.