Light Receiving Device With Nested Isolation Portions
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Solution Overview
Problem
Existing light receiving devices face challenges in preventing noise due to crosstalk between adjacent photoelectric transducers while achieving high light-receiving sensitivity, which affects their performance in applications such as distance measuring and light detection.
Innovation Solution
The light receiving device incorporates a configuration with isolation areas and a quench resistor to prevent crosstalk, featuring a semiconductor substrate with P-type and N-type semiconductor layers, metal isolation areas, and a control circuit to manage the output of photoelectric transducers, ensuring effective electrical and optical isolation between adjacent transducers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If isolation structures are added between adjacent photoelectric transducers, then crosstalk noise is reduced, but device complexity increases
Solution Approach 1:
The patent divides the semiconductor substrate into multiple isolated photoelectric transducer regions by introducing isolation portions between adjacent transducers. This segmentation physically separates the transducers to prevent crosstalk while maintaining their individual functionality, directly resolving the contradiction between noise reduction and device complexity.
Solution Approach 2:
The patent introduces isolation portions as intermediary structures between adjacent photoelectric transducers. These isolation portions act as mediators that block electrical and optical interference between transducers, reducing crosstalk noise without requiring complete physical separation of the transducers.
2Reliability
If multiple isolation portions are embedded in isolation areas, then crosstalk prevention is improved, but manufacturing complexity increases
Solution Approach 1:
The patent embeds multiple isolation portions within isolation areas in a nested configuration. The first isolation portions are positioned between adjacent second semiconductor regions, while second isolation portions are embedded within the first isolation portions. This nesting approach maximizes isolation effectiveness within limited space while streamlining the manufacturing process by combining multiple isolation functions into hierarchical structures.
Solution Approach 2:
The patent extends isolation from a two-dimensional planar arrangement to a three-dimensional nested structure by embedding isolation portions vertically within isolation areas. This dimensional transition allows multiple isolation layers to coexist without proportionally increasing manufacturing complexity, as they can be formed through sequential processing steps.
3Area of stationary object
If photoelectric transducers are arranged closely to increase detection area, then light-receiving capability is improved, but crosstalk noise increases
Solution Approach 1:
The patent applies different properties to different regions: photoelectric transducers have high conductivity for signal detection, while isolation portions have low conductivity to block crosstalk. This local differentiation allows closely spaced transducers to maintain high detection area while preventing noise through region-specific property optimization.
Solution Approach 2:
The patent uses identical isolation portion structures repeated between each pair of adjacent photoelectric transducers. This copying of the isolation structure across the array provides consistent crosstalk prevention throughout the detection area, enabling uniform noise reduction across all transducer pairs.
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 noise from crosstalk and enhances light-receiving sensitivity, allowing for accurate detection of incident photons and improved performance in applications like distance measuring and digital imaging.
Implementation Method 1
a light receiving device in which avalanche photodiodes, which are a kind of photoelectric transducer, are connected in parallel and the number of incident photons is measured
Implementation Method 2
avalanche photodiodes, which are a kind of photoelectric transducer
Data Source
AI summary
A light receiving device comprises a substrate of a first type on a first electrode, a first region of the first type on the substrate, second regions of the first type arrayed on the first region, and third regions of a second type on the second regions. A first isolation portion is between the adjacent second regions and adjacent third regions. A second isolation portion comprising a metal is embedded the first isolation portions. A fourth region of the second type is on the first region and spaced from the second regions in a second direction with a pair of fifth regions thereon. An insulating film is on the fourth region and the pair of fifth regions. A second electrode is on the insulating film between the pair of fifth regions. The second electrode is comprised of the same metal as the second isolation portion.