Nitride LED N-Layer Doping Structure for Lower Forward Voltage
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Solution Overview
Problem
Current methods for manufacturing light-emitting elements face challenges in reducing forward voltage, which affects their efficiency and performance.
Innovation Solution
A method involving the formation of nitride semiconductor layers with specific compositions and structures, including n-layers with varying concentrations of Al, Ga, Si, and Ge, and the use of metal organic chemical vapor deposition (MOCVD) to create a semiconductor structure that emits ultraviolet light, with a p-electrode and n-electrode configuration to optimize electrical connections and crystallizability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional methods using single impurity doping (Si or Ge) are used to create n-type gallium nitride semiconductor, then the manufacturing process is simple, but the forward voltage cannot be effectively reduced
Solution Approach 1:
The patent applies local quality by creating distinct n-layer regions with different impurity compositions: a first n-layer with Ge impurity near the substrate for crystallization control, and a second n-layer with Si impurity above it for electrical conductivity. This spatial differentiation of impurity types and concentrations optimizes both forward voltage reduction and manufacturing feasibility
Solution Approach 2:
The patent uses composite materials by combining multiple impurity elements (Ge and Si) in specific concentrations within the gallium nitride semiconductor layers. The first n-layer contains Ge at 1×10^18 to 1×10^20 atoms/cm³, while the second n-layer contains Si at 1×10^18 to 1×10^20 atoms/cm³, creating a composite doped structure that achieves superior electrical properties compared to single impurity doping
2Loss of energy
If multi-layer n-structure with different impurities is formed to reduce forward voltage, then energy loss is reduced, but the manufacturing process complexity increases
Solution Approach 1:
The patent segments the n-type semiconductor structure into multiple functional layers: a first n-layer formed with Ge-containing source gas for crystallization control, and a second n-layer formed with Si-containing source gas for conductivity enhancement. This segmentation allows each layer to be optimized independently while simplifying the overall manufacturing process through systematic impurity introduction
Solution Approach 2:
The patent applies parameter changes by systematically varying impurity type (Ge vs Si), concentration (1×10^18 to 1×10^20 atoms/cm³), and layer position during the semiconductor formation process. These parameter variations are introduced through controlled changes in source gas composition during MOCVD growth, enabling precise control of electrical properties while maintaining manufacturing efficiency
3Reliability
If Ge concentration is increased near the substrate to improve crystallizability, then crystal quality improves, but Si concentration needs to be increased in upper layers for conductivity
Solution Approach 1:
The patent applies preliminary action by introducing Ge impurity in the first n-layer close to the substrate before forming the second n-layer. This preliminary Ge doping establishes strong crystallization nuclei that promote high-quality crystal growth in subsequent layers, ensuring reliable crystallizability before the conductivity-optimizing Si-doped second n-layer is formed
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 reduces forward voltage, enhances crystallizability, and improves light extraction efficiency, leading to more effective light-emitting elements.
Implementation Method 1
forming an active layer made of a nitride semiconductor layer that emits ultraviolet light
Implementation Method 2
forming a first n-layer made of a nitride semiconductor layer above a first substrate by using a first source gas including an Al source gas, a Ga source gas, and a Ge source gas
Data Source
AI summary
A method for manufacturing a light-emitting element includes forming a first n-layer made of a nitride semiconductor layer above a first substrate using a first source gas including an Al source gas, a Ga source gas, and a Ge source gas. The method further includes forming a second n-layer made of a nitride semiconductor layer above the first n-layer using a second source gas including an Al source gas, a Ga source gas, and a Si source gas, exposing the second n-layer by removing the first substrate and the first n-layer, and forming an n-electrode on the second n-layer exposed in the exposing of the second n-layer.