Light Detector Structure for Dark Current and Crosstalk Suppression
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Solution Overview
Problem
Conventional light detectors face reliability issues due to erroneous light detection caused by dark electric currents and crystal defects, leading to reduced accuracy and increased crosstalk noise.
Innovation Solution
The light detector design incorporates a p−-type and n+-type semiconductor region structure with a separation part and quenching mechanism, which suppresses avalanche breakdown and dark electric currents, enhancing reliability and accuracy by separating the depletion layers and reducing crosstalk noise through a multi-layered semiconductor and insulating structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional light detector structure is used, then the device is simple to manufacture, but dark electric currents and crystal defects cause erroneous light detection, reducing reliability
Solution Approach 1:
The semiconductor region is divided into multiple doped regions (first doped region, second doped region, third doped region, fourth doped region) with different conductivity types and impurity concentrations. This segmentation creates separate functional zones that suppress dark currents and reduce crosstalk noise, thereby improving detection accuracy without requiring external suppression components.
Solution Approach 2:
Different regions of the semiconductor structure are assigned different local properties: the first and second doped regions have first conductivity type with specific impurity concentrations, while the third and fourth doped regions have second conductivity type. This local quality variation optimizes each region's function in suppressing dark currents and reducing crosstalk, enhancing overall reliability.
2Measurement precision
If separation parts are added to reduce crosstalk noise, then detection accuracy improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The crosstalk suppression function is merged into the semiconductor substrate itself through doped regions, rather than adding separate physical separation parts. The second doped region and fourth doped region act as integrated suppression zones that reduce crosstalk noise between adjacent elements, achieving measurement precision improvement without increasing manufacturing complexity.
Solution Approach 2:
The third doped region with second conductivity type acts as an intermediary between the first and fourth doped regions. This intermediate region suppresses dark electric currents and reduces crosstalk noise by providing a controlled electrical pathway, thereby improving light detection accuracy through an integrated mediator rather than external separation structures.
3Reliability
If avalanche breakdown is suppressed through additional structures, then reliability improves, but the device becomes more complex
Solution Approach 1:
The doped regions are pre-configured during manufacturing to create depletion layers that prevent avalanche breakdown before it occurs. The specific impurity concentrations and conductivity types of the doped regions establish electric field distributions that suppress breakdown phenomena, ensuring operational stability through preliminary structural design rather than active control mechanisms.
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 effectively reduces dark count rates and crosstalk noise, improving the reliability and accuracy of light detection by stabilizing the electric potential and reducing secondary photon interference.
Implementation Method 1
dark electric currents and crystal defects, leading to reduced accuracy and increased crosstalk noise
Implementation Method 2
a light detector detecting light incident on a semiconductor region
Data Source
AI summary
According to one embodiment, a light detector includes a plurality of elements, a plurality of separation parts, a fourth semiconductor region, a fifth semiconductor region, a first interconnect, a first quenching part, and a second interconnect. The elements are located in a cell region and arranged. Each of the elements includes first, second, and third semiconductor regions. The second semiconductor region is located on the first semiconductor region. The third semiconductor region is located on the second semiconductor region. The separation parts are located respectively around the elements. The fourth semiconductor region is located around each of the separation parts. The fifth semiconductor region is located on the fourth semiconductor region. The first interconnect is electrically connected to the third semiconductor regions. The first quenching part is electrically connected to the first interconnect. The second interconnect is electrically connected to the fifth semiconductor region.