Semiconductor Light Emitting Element Dual Protective Layer Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing semiconductor light emitting elements face issues with poor output characteristics and moisture resistance due to the use of silicon oxide as a protective layer, which is difficult to etch and may damage the semiconductor layer, and aluminum oxide, which is hard to etch but provides excellent moisture resistance.
Innovation Solution
A semiconductor light emitting element design that includes a first protective layer of silicon oxide or silicon oxynitride on the p-type semiconductor layer for enhanced ultraviolet light reflection and a second protective layer of aluminum oxide or aluminum nitride covering the lateral surfaces for improved moisture resistance, allowing for the formation of electrodes without damaging the p-type semiconductor layer during etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon oxide (SiO2) is used as a protective layer, then it provides protective function, but it has poor moisture resistance and requires large thickness
Solution Approach 1:
The patent uses a composite protective layer structure combining silicon oxide (or silicon oxynitride) and aluminum oxide (or aluminum nitride). The first protective layer uses silicon oxide for UV reflection, while the second protective layer uses aluminum oxide for moisture resistance. This composite structure resolves the contradiction by leveraging the strengths of both materials rather than relying on a single material to provide all protective functions.
2Object-affected harmful factors
If aluminum oxide (Al2O3) is used as a protective layer, then it has excellent moisture resistance, but it is difficult to etch and may damage the semiconductor layer
Solution Approach 1:
The protective layer is segmented into two distinct layers with different functions. The first protective layer (silicon oxide) is positioned where etching is needed to form electrodes, while the second protective layer (aluminum oxide) is positioned to provide moisture resistance. This segmentation allows each layer to be optimized for its specific function, resolving the contradiction between etchability and moisture resistance.
Solution Approach 2:
Different regions of the protective structure have different material compositions tailored to local requirements. The first protective layer uses materials with good etchability in regions where electrode formation is needed, while the second protective layer uses materials with excellent moisture resistance in regions where protection is prioritized. This local quality approach resolves the contradiction by applying the right material properties in the right locations.
3Device complexity
If a single protective layer is used, then the structure is simple, but it cannot simultaneously provide both UV light reflection and moisture resistance
Solution Approach 1:
The patent employs a composite protective layer structure where the first protective layer (silicon oxide or silicon oxynitride) provides UV light reflection through its low refractive index, and the second protective layer (aluminum oxide or aluminum nitride) provides moisture resistance through its excellent barrier properties. This composite structure resolves the contradiction by combining multiple materials, each optimized for a specific function, thereby achieving both UV reflection and moisture resistance simultaneously.
4Use of energy by moving object
If silicon oxide protective layer is used, then UV light reflection is enhanced, but moisture resistance deteriorates
Solution Approach 1:
The patent uses a composite protective layer structure where the first protective layer (silicon oxide or silicon oxynitride) enhances UV light reflection to improve external quantum efficiency, while the second protective layer (aluminum oxide or aluminum nitride) provides excellent moisture resistance. This composite structure resolves the contradiction by combining materials with complementary properties, allowing both UV reflection enhancement and moisture resistance to be achieved simultaneously without compromising either function.
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 design increases external quantum efficiency by reflecting more ultraviolet light and enhances moisture resistance, preventing damage to the semiconductor layers during the etching process and improving the contact resistance of the electrodes.
Implementation Method 1
providing the first protective layer of a low refractive index made of silicon oxide (SiO2) or silicon oxynitride (SiON) on the p-type semiconductor layer ensures that more ultraviolet light is totally reflected at the interface between the p-type semiconductor layer and the first protective layer
Implementation Method 2
aluminum oxide (Al2O3) has an excellent moisture resistance but is difficult to etch
Data Source
AI summary
A semiconductor light emitting element includes: an n-type semiconductor layer provided on a substrate; an active layer provided in a first region of the n-type semiconductor layer and made of an AlGaN-based semiconductor material; a p-type semiconductor layer provided on the active layer; a first protective layer provided on the p-type semiconductor layer and made of silicon oxide (SiO2) or silicon oxynitride (SiON); a second protective layer provided to cover a top of the first protective layer, a second region on the n-type semiconductor layer different from the first region, and a lateral surface of the active layer and made of aluminum oxide (Al2O3), aluminum oxynitride (AlON), or aluminum nitride (AlN); a p-side electrode provided contiguously on the p-type semiconductor layer; and an n-side electrode provided contiguously on the n-type semiconductor layer.