APD Array Multiplication Layer Layout to Reduce Dead Areas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Avalanche photodiode arrays face challenges with dead areas between photodiodes, which are not effectively addressed by existing configurations, particularly those using microlens arrays, leading to high costs and complex manufacturing processes, and limited capability in detecting electromagnetic waves and particle beams.
Innovation Solution
The proposed avalanche photodiode array features a semiconductor substrate with a specific layer configuration, including a first conductivity type semiconductor layer, second conductivity type semiconductor layers, and a multiplication layer, where the multiplication layer is continuously provided to overlap the second semiconductor layers, reducing dead areas and suppressing edge breakdown, allowing for detection of electromagnetic waves and particle beams without a microlens array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a microlens array is used to guide light from dead areas to detectable areas, then the light receiving range is expanded, but the manufacturing cost increases and the number of manufacturing steps increases
Solution Approach 1:
The patent merges the multiplication layer with the photodiode structure by providing it as a continuous layer overlapping multiple second semiconductor layers. This integration eliminates the need for separate microlens arrays while achieving both dead area reduction and light guidance functions through the unified semiconductor structure.
Solution Approach 2:
The patent extracts the microlens array from the system and replaces it with a semiconductor-based multiplication layer that performs the light guidance function. The multiplication layer is provided within the semiconductor region and continuously overlaps the second semiconductor layers, eliminating external optical components.
2Reliability
If a microlens array is used to expand the light receiving range, then dead areas are reduced, but the manufacturing cost and process complexity increase
Solution Approach 1:
The multiplication layer is merged with the photodiode structure as an integrated semiconductor component. It is provided within the semiconductor region and continuously overlaps the second semiconductor layers, combining dead area reduction and light detection functions in a single manufacturable structure.
Solution Approach 2:
The multiplication layer acts as an intermediary between the second semiconductor layers and the first semiconductor layer. It facilitates carrier multiplication and transport while maintaining a simple continuous structure that is easier to manufacture than microlens arrays.
3Measurement precision
If a microlens array is used for dead area reduction, then light detection is improved, but the configuration becomes complex and costly
Solution Approach 1:
The multiplication layer is merged with the photodiode structure as a continuous semiconductor layer that overlaps multiple second semiconductor layers. This integration achieves precise carrier multiplication and detection while maintaining a simple configuration without external microlens arrays.
Solution Approach 2:
The patent uses composite semiconductor structures with different conductivity types (first conductivity type for first semiconductor layer, second conductivity type for second semiconductor layers and multiplication layer) to achieve precise detection functionality within a unified material system.
4Productivity
If the multiplication layer is continuously provided to overlap second semiconductor layers, then dead areas are reduced and detection capability is improved, but edge breakdown may occur in second semiconductor layers
Solution Approach 1:
The patent applies local quality by providing the multiplication layer with specific conductivity type (second conductivity type) that differs from the first semiconductor layer. This local differentiation enables efficient carrier multiplication in the multiplication layer while the surrounding semiconductor region structure prevents edge breakdown in the second semiconductor layers.
Solution Approach 2:
The patent uses composite semiconductor structures with alternating conductivity types to create favorable electric field distributions. The combination of first conductivity type (first semiconductor layer) and second conductivity type (second semiconductor layers and multiplication layer) materials enables both high-speed carrier multiplication and edge breakdown suppression.
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 configuration reduces dead areas and enhances the detection of electromagnetic waves and particle beams by providing a wider sensitive layer, improving detection accuracy and response speed while simplifying the manufacturing process and reducing costs.
Implementation Method 1
The multiplication layer includes a third semiconductor layer of the second conductivity type and a fourth semiconductor layer of the second conductivity type facing each other
Implementation Method 2
An avalanche photodiode array includes a semiconductor substrate and a plurality of avalanche photodiodes arranged on the semiconductor substrate
Data Source
AI summary
In an APD array, a plurality of APDs include a first semiconductor layer, a plurality of second semiconductor layers, and a multiplication layer. The first semiconductor layer is provided closer to the second surface than a semiconductor region. The plurality of second semiconductor layers are arranged along a first surface. The multiplication layer is provided within the semiconductor region and provided between the plurality of second semiconductor layers and the first semiconductor layer in a direction perpendicular to the first surface. Each of a third semiconductor layer and a fourth semiconductor layer of the multiplication layer is continuously provided so as to overlap the plurality of second semiconductor layers when viewed in the direction perpendicular to the first surface. The third semiconductor layer is provided closer to the first surface than the fourth semiconductor layer.