Nitride Semiconductor Light-Emitting Device with Ridge Waveguide
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Solution Overview
Problem
Nitride semiconductor light-emitting devices, such as lasers and super-radiance light-emitting diodes, face issues with high series resistance, thermal power, and reduced performance due to large p-type layer resistance, low optical field limitation, and inefficient heat dissipation, leading to elevated junction temperatures and shortened service life.
Innovation Solution
A nitride semiconductor light-emitting device with a ridge waveguide structure is developed, featuring a (0001) nitrogen face for p-type ohmic contact and the use of low-refractive-index materials for optical field limitation, along with a reduced p-type contact layer thickness and improved heat conduction paths to minimize thermal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of the p type nitride semiconductor layer is increased to 500 nm or more for good optical field limitation, then the optical field limitation is improved, but the series resistance becomes large causing high voltage drop and thermal power
Solution Approach 1:
The patent divides the p type nitride semiconductor layer into multiple sub-layers with different thicknesses and doping concentrations. The layer adjacent to the active region has smaller thickness and higher doping concentration to reduce resistance, while layers farther away have larger thickness to provide optical field limitation. This segmentation allows simultaneous optimization of both electrical and optical properties.
Solution Approach 2:
Different regions of the p type nitride semiconductor layer are assigned different local properties: the region near the active region has higher doping concentration and smaller thickness for low resistance, while regions farther away have lower doping concentration and larger thickness for optical field limitation. This local quality differentiation resolves the contradiction between resistance and optical confinement.
2Reliability
If the doping concentration of Mg acceptor is increased to improve hole concentration, then the electrical conductivity is improved, but the effective mass of holes increases and migration rate decreases
Solution Approach 1:
The patent optimizes the Mg acceptor doping concentration to a specific range that balances hole concentration and hole mobility. By carefully controlling the doping concentration parameter, the patent achieves sufficient electrical conductivity while minimizing the increase in effective mass that would reduce hole migration rate.
3Reliability
If the refractive index difference between AlGaN optical limiting layer and waveguide layer is increased to improve optical field limitation, then the optical confinement is improved, but the device complexity increases
Solution Approach 1:
The patent adjusts the Al composition ratio in the AlGaN optical limiting layer to optimize the refractive index difference with the waveguide layer. By changing this material parameter, the patent achieves improved optical field limitation without adding structural complexity or additional layers.
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 solution results in reduced device resistance, enhanced electro-optic efficiency, lower thermal power, and extended performance and service life, with improved reliability and stability, particularly for AlGaN-based ultraviolet lasers and super-radiance light-emitting diodes.
Implementation Method 1
featuring a (0001) nitrogen face for p-type ohmic contact
Implementation Method 2
the use of low-refractive-index materials for optical field limitation
Implementation Method 3
along with a reduced p-type contact layer thickness and improved heat conduction paths to minimize thermal resistance
Data Source
AI summary
The present application discloses a nitride semiconductor light-emitting device and a manufacture method thereof. The nitride semiconductor light-emitting device includes an epitaxial structure, wherein the epitaxial structure has a first face and a second face opposite to the first face, the first face is a (0001) nitrogen face and located at the n type side of the epitaxial structure, the second face is located at the p type side of the epitaxial structure, the n type side of the epitaxial structure is electrically contacted with an n type electrode, the p type side is electrically contacted with a p type electrode, and a ridge waveguide structure is formed on the first face. The nitride semiconductor light-emitting device, especially a III-V nitride semiconductor laser or a super-radiance light-emitting diode, of the present application, has the advantages of low resistance, low internal loss, small threshold current, small thermal resistance and good stability and reliability and the like, and meanwhile the preparation process is simple and is easily implemented.