Light Sensor Infrared Absorption via Light Splitters
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Solution Overview
Problem
The quantum efficiency of light sensors using near-infrared light is low due to the long wavelength of infrared light, which results in low absorption and conversion of infrared light into charge, leading to reduced sensitivity and performance.
Innovation Solution
A light sensor design incorporating a deep trench isolation structure, micro lenses, light splitters, and photoelectric-conversion-enhancing layers is employed. The light splitters are positioned at the focal point of the micro lenses to scatter and increase the light path within the sensor, enhancing the absorption of infrared light, while the photoelectric-conversion-enhancing layers improve the conversion efficiency of the photoelectric converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional light sensor design is used, then结构简单性 is maintained, but quantum efficiency of near-infrared light is low
Solution Approach 1:
The light sensor structure is segmented into multiple functional layers: micro lens layer, light splitter layer, photoelectric-conversion-enhancing layer, and photoelectric converter layer. Each layer performs a specific function to progressively enhance near-infrared light absorption and conversion efficiency, resolving the contradiction by dividing the complex light interaction process into manageable segments.
Solution Approach 2:
The patent introduces a vertical stacking dimension by placing multiple functional layers (micro lenses, light splitters, enhancing layers, photoelectric converters) in sequence along the light path. This vertical arrangement allows light to interact with multiple interfaces and layers, increasing absorption opportunities without significantly expanding the planar footprint, thus improving quantum efficiency while controlling structural complexity.
2Reliability
If light splitters are positioned at focal point of micro lenses, then light path length is increased, but manufacturing precision requirements increase
Solution Approach 1:
The light splitters are pre-positioned at the focal points of the micro lenses during the manufacturing process. This preliminary positioning ensures that incoming light is optimally scattered and redirected through the photoelectric-conversion-enhancing layer, maximizing the light path length and absorption factor before the light reaches the photoelectric converters.
Solution Approach 2:
The light splitters are strategically positioned only at specific locations (focal points of micro lenses) rather than uniformly distributed throughout the structure. This localized placement optimizes light scattering precisely where needed to enhance absorption, while avoiding unnecessary complexity in other regions, thus balancing manufacturing precision requirements with performance enhancement.
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 design significantly increases the absorption factor and quantum efficiency of infrared light, thereby enhancing the sensitivity and performance of the light sensor, particularly for near-infrared wavelengths.
Implementation Method 1
The light splitters are positioned at the focal point of the micro lenses
Implementation Method 2
The light splitters are positioned at the focal point of the micro lenses to scatter and increase the light path within the sensor
Implementation Method 3
Each of a plurality of photoelectric converters is disposed in one of the plurality of unit pixel regions
Data Source
AI summary
A first substrate includes a plurality of unit pixel regions. A deep trench isolation structure is disposed in the first substrate and isolates each of the plurality of the unit pixel regions from each other. Each of a plurality of photoelectric converters is disposed in one of the plurality of unit pixel regions. A plurality of micro lenses are disposed on the first substrate. A plurality of light splitters are disposed on the first substrate. Each of the plurality of light splitters is disposed between one of the plurality of micro lenses and one of the plurality of photoelectric converters. Each of a plurality of photoelectric-conversion-enhancing layers is disposed between one of the plurality of light splitters and one of the plurality of photoelectric converters.