Multi-Wavelength VCSEL Arrays on Single Substrate
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Solution Overview
Problem
Existing multi-wavelength light-emitting semiconductor devices require complex alignment processes and additional manufacturing steps to integrate different devices with varying emission wavelengths, leading to increased costs and potential performance issues in applications like facial recognition systems.
Innovation Solution
The development of multi-wavelength light-emitting (MWLE) semiconductor devices with VCSEL arrays fabricated on the same substrate, utilizing a light emission layer with III-V compound semiconductor materials and oxidized apertures, allows for multiple emission wavelengths in close proximity without the need for alignment processes, using nitrogen and indium concentrations to tune the energy bandgap and minimize lattice mismatch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different devices with different emission wavelengths are integrated, then multi-wavelength light emission is achieved, but alignment complexity and manufacturing cost increase
Solution Approach 1:
The patent merges multiple VCSEL devices with different emission wavelengths onto a single substrate, forming an integrated VCSEL array. This combining approach achieves multi-wavelength light emission while eliminating the need for complex alignment processes between separate devices, as all VCSELs are fabricated together in the same device structure
Solution Approach 2:
The patent creates a universal substrate structure that can accommodate multiple VCSEL devices with different emission wavelengths simultaneously. The common substrate and integrated fabrication process enable the system to perform multiple wavelength functions through a single unified device architecture rather than requiring separate alignment procedures for each wavelength
2Adaptability or versatility
If different devices with different emission wavelengths are integrated, then multi-wavelength light emission is achieved, but manufacturing cost increases
Solution Approach 1:
The patent combines multiple VCSEL devices into a single integrated array on one substrate, which reduces manufacturing cost by eliminating the need to separately fabricate and assemble multiple discrete devices. The integrated structure allows for batch fabrication processes that are more cost-effective than individual device manufacturing and assembly
3Area of stationary object
If VCSELs with different emission wavelengths are placed in close proximity, then space efficiency is improved, but alignment precision requirements increase
Solution Approach 1:
The patent merges multiple VCSEL devices into a single integrated array where all devices are fabricated together on the same substrate. This merging eliminates the need for post-fabrication alignment between separate devices, as the close-proximity emission regions are automatically precisely positioned during the integrated fabrication process itself
Solution Approach 2:
The patent performs the positioning and alignment of multiple VCSEL emission regions during the initial fabrication process on the substrate, before the device is completed. This preliminary action of establishing precise relative positions during manufacturing eliminates the need for subsequent alignment procedures and ensures accurate spatial arrangement of close-proximity emission regions
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 manufacturing complexity and cost while enhancing alignment and performance, enabling efficient multi-wavelength light emission for applications such as facial recognition systems with improved device performance and extended wavelength tunability.
Implementation Method 1
Each of the apertures is surrounded by an oxidized oxidation layer
Implementation Method 2
The nitrogen atom concentration range in the light emission layer can advantageously allow the energy bandgap of the III-V compound semiconductor material to be tuned to a smaller energy bandgap compared to III-V compound semiconductor materials without nitrogen atom or with nitrogen atom concentration above about 5%. As a result, the III-V compound semiconductor material with the smaller energy bandgap advantageously allows the light emission layer to have a longer primary emission wavelength
Implementation Method 3
The indium atom concentration range in the light emission layer can advantageously minimize lattice mismatch between the III-V compound semiconductor material and the material of the substrate
Implementation Method 4
Free carriers in the form of holes and electrons are injected into the quantum wells, when the PN junction is forward biased by an electrical current. At a sufficient bias current, the injected minority carriers form a population inversion in the quantum wells that produce optical gain, which is used inside a resonant cavity to cause lasing in VCSELs
Data Source
AI summary
A multi-wavelength light-emitting semiconductor device and a method of fabricating the same are disclosed. The semiconductor device includes a substrate, a first reflector on the substrate, a light emission layer on the first reflector, second reflectors on corresponding active regions; and apertures on corresponding active regions. The light emission layer includes active regions. Each of the active regions includes a primary emission wavelength different from each other.