Light Sensor Trench Structure Infrared Detection
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Solution Overview
Problem
Existing light sensors in electronic devices have limitations in detecting gestures and tracking complex movements due to limited range and sensitivity, particularly in detecting infrared light, which requires improved charge carrier generation and absorption mechanisms.
Innovation Solution
The integration of a trench structure within light sensors, featuring a substrate with a dopant material of a first conductivity type and a diffusion region of a second conductivity type, creating a depletion region that attracts charge carriers generated by incident light, including infrared light, thereby enhancing charge carrier density and detection depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional photodetector structures are used, then the device complexity is low, but the sensitivity and detection depth for infrared light are insufficient
Solution Approach 1:
The photodetector structure is segmented into multiple regions including a substrate, trenches, diffusion regions, and depletion regions. This segmentation creates multiple interfaces and zones that enhance light absorption and charge carrier separation, thereby improving sensitivity without excessive complexity
Solution Approach 2:
The patent introduces vertical depletion regions extending from the substrate surface into the bulk material, adding a depth dimension to the detection capability. This vertical dimension enables detection of infrared light that generates charge carriers at greater depths, improving detection depth and sensitivity
2Length of stationary object
If the detection range is extended to deeper charge carriers, then the range improves, but the charge carrier attraction efficiency decreases
Solution Approach 1:
Depletion regions are pre-formed during device fabrication, establishing electric fields before light exposure. These pre-established fields are positioned to extend into deeper regions of the substrate, enabling efficient attraction of charge carriers generated by infrared light at greater depths
Solution Approach 2:
The patent introduces intermediate structures including trenches and diffusion regions that act as mediators between the substrate and the depletion regions. These intermediaries facilitate the formation of extended depletion zones that can efficiently attract charge carriers from deeper regions while maintaining structural integrity
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 improves the sensitivity and range of light sensors by attracting a majority of charge carriers to the depletion region, allowing for deeper detection of infrared light and improved gesture detection capabilities.
Implementation Method 1
A depletion region is created at the interface of the dopant material of the first conductivity type and the dopant material of the second conductivity type. The depletion region is configured to attract charge carriers to the depletion region
Implementation Method 2
A depletion region is created at the interface of the dopant material of the first conductivity type and the dopant material of the second conductivity type
Implementation Method 3
charge carriers generated due to light incident upon the substrate
Data Source
AI summary
Light sensors are described that include a trench structure integrated therein. In an implementation, the light sensor includes a substrate having a dopant material of a first conductivity type and multiple trenches disposed therein. The light sensor also includes a diffusion region formed proximate to the multiple trenches. The diffusion region includes a dopant material of a second conductivity type. A depletion region is created at the interface of the dopant material of the first conductivity type and the dopant material of the second conductivity type. The depletion region is configured to attract charge carriers to the depletion region, at least substantially a majority of the charge carriers generated due to light incident upon the substrate.