Waveguide Photodetector Structure With Charge and Multiplication Regions
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Solution Overview
Problem
The responsivity of waveguide photodetectors is low, requiring increased optical power for substantial photocurrent generation.
Innovation Solution
Incorporating a charge region and an intrinsic multiplication region into the waveguide photodetector to enhance carrier multiplication and photocurrent generation without increasing optical power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional semiconductor waveguide photodetector structure is used, then the device complexity is low, but the responsivity is low requiring high optical power
Solution Approach 1:
The photodetector is segmented into distinct functional regions: an absorption region for photon absorption, a charge region for carrier separation, and a multiplication region for carrier multiplication. This segmentation allows each region to be optimized for its specific function, improving overall responsivity while maintaining manageable device complexity through modular design
Solution Approach 2:
Different regions of the photodetector are doped with different doping concentrations to create local quality variations. The absorption region has one doping concentration, the charge region has a different doping concentration, and the multiplication region has yet another doping concentration. This local quality differentiation enables optimized performance in each region, resolving the contradiction between improved responsivity and device complexity
2Productivity
If optical power is increased to achieve substantial photocurrent generation, then the photocurrent increases, but the energy consumption increases
Solution Approach 1:
The invention changes the electrical parameters (doping concentrations) of different regions to optimize the optical-to-electrical conversion process. By carefully controlling the doping concentrations in the absorption, charge, and multiplication regions, the device achieves higher photocurrent generation efficiency, reducing the optical power required for substantial photocurrent generation
Solution Approach 2:
The charge region acts as an intermediary between the absorption region and the multiplication region. It facilitates efficient carrier separation and transport, enabling the multiplication region to effectively amplify the photocurrent signal. This intermediary function improves the overall conversion efficiency, reducing the optical power needed for substantial photocurrent generation
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 addition of the charge and intrinsic multiplication regions increases photocurrent generation and responsivity of the waveguide photodetector, reducing the required optical power.
Implementation Method 1
The second semiconductor layer forms an absorption region of the waveguide photodetector. The absorption region is configured to absorb photons traveling through the waveguide.
Implementation Method 2
The waveguide photodetector is configured to convert an optical signal (e.g., optical radiation) traveling through the waveguide into an electrical signal (e.g., current).
Implementation Method 3
Incorporating a charge region and an intrinsic multiplication region into the waveguide photodetector structure to enhance carrier multiplication, thereby increasing photocurrent without increasing optical power.
Data Source
AI summary
A waveguide photodetector includes a slab over a substrate, first and second contact portions protruding upward from the slab, and a ridge protruding upward from the slab between the first and second contact portions. A first semiconductor layer is over the substrate and includes a first doped region in the first contact portion, a second doped region in the slab between the first contact portion and the ridge, a third doped region and a sixth doped region in the ridge, a fourth doped region in the second contact portion, a fifth doped region in the slab between the second contact portion and the ridge, a first intrinsic region between the sixth and third doped regions, and a second intrinsic region between the sixth and fifth doped regions. A second semiconductor layer is over the first intrinsic region and between the sixth and third doped regions.