APD Photodetector Layout With Carrier Absorption for Temperature Compensation
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Solution Overview
Problem
The existing light detection devices face challenges in achieving accurate temperature compensation for avalanche photodiodes (APDs) while maintaining low manufacturing costs, as they require selecting and combining APDs with specific temperature characteristics, which complicates the process and increases costs.
Innovation Solution
A light detection device is designed with an avalanche photodiode (APD) and a temperature compensation diode formed on the same semiconductor substrate, utilizing a peripheral carrier absorbing portion to absorb carriers generated by the temperature compensation diode, ensuring accurate temperature compensation and reducing manufacturing costs by simplifying the formation of APDs with desired temperature characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If APDs with the same temperature characteristics are selected and combined from different semiconductor substrates, then temperature compensation accuracy is improved, but manufacturing cost increases and manufacturing complexity increases
Solution Approach 1:
The patent merges the APD and temperature compensation diode onto a single semiconductor substrate, eliminating the need to select and combine separate components from different substrates. This integration maintains temperature compensation accuracy while significantly reducing manufacturing cost and complexity by producing both components through the same fabrication process.
Solution Approach 2:
The semiconductor substrate serves multiple functions by simultaneously hosting both the APD for light detection and the temperature compensation diode for temperature stabilization. This multi-functional design allows both components to share the same substrate environment and fabrication process, resolving the contradiction between accuracy and manufacturability.
2Measurement precision
If APDs with the same temperature characteristics are selected and combined from different semiconductor substrates, then temperature compensation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent combines the APD and temperature compensation diode on a single semiconductor substrate, simplifying the manufacturing process by eliminating the need to handle, select, and assemble separate components from different substrates. This integration reduces device complexity while maintaining temperature compensation accuracy.
3Ease of manufacture
If the temperature compensation diode and APD are formed on the same semiconductor substrate, then manufacturing cost is reduced and ease of manufacture is improved, but carrier interference may occur affecting detection accuracy
Solution Approach 1:
The patent extracts the harmful carriers generated by the temperature compensation diode from the region near the APD by introducing a dedicated carrier removal region. This separation function removes the interference source from the detection path while keeping both components on the same substrate, thus maintaining manufacturing advantages while protecting detection accuracy.
Solution Approach 2:
The carrier removal region acts as an intermediary structure between the temperature compensation diode and the APD. It mediates the interaction by capturing and removing carriers before they can reach the APD, thus enabling coexistence on the same substrate without compromising detection accuracy.
4Reliability
If the temperature compensation diode emits light, then temperature compensation function is achieved, but carriers are generated that may interfere with APD detection
Solution Approach 1:
The patent extracts the harmful carriers generated by the temperature compensation diode's light emission through the carrier removal region. This region specifically targets and removes the carriers before they can reach the APD, allowing the temperature compensation diode to function reliably without generating interference.
Solution Approach 2:
The patent converts the harmful carrier generation effect into a beneficial situation by using the carrier removal region to capture these carriers. The carriers that would otherwise interfere with detection are now utilized to fill the carrier removal region, which is designed to accommodate and neutralize them, thus transforming the harmful effect into a controlled and beneficial state.
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 enhances detection accuracy while reducing manufacturing costs by allowing for easier formation of APDs with matching temperature characteristics and effectively suppressing carrier interference from the temperature compensation diode, thus improving the overall performance of the light detection device.
Implementation Method 1
When a breakdown voltage is applied to the temperature compensation diode, the temperature compensation diode may emit light. When the temperature compensation diode emits light, carriers are generated in the semiconductor substrate due to the light emitted from the temperature compensation diode.
Implementation Method 2
When the temperature compensation diode emits light, carriers are generated in the semiconductor substrate due to the light emitted from the temperature compensation diode.
Implementation Method 3
The peripheral carrier absorbing portion is configured to absorb carriers located at the periphery.
Data Source
AI summary
In a light detection device, the semiconductor substrate forms an APD and a temperature compensation diode so as to be spaced apart from each other. The semiconductor substrate includes a peripheral carrier absorbing portion configured to absorb carriers located at the periphery, between the APD and the temperature compensation diode when viewed from the direction perpendicular to the main surface. When viewed from the direction perpendicular to the main surface, on a line segment connecting the APD and the temperature compensation diode at the shortest distance, the shortest distance between the APD and the peripheral carrier absorbing portion is smaller than the shortest distance between the temperature compensation diode and a portion, which is closest to the APD, of edges of the peripheral carrier absorbing portion.