Semiconductor Optical Sensor UV Visible Detection

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Solution Overview

Problem

Existing semiconductor optical sensors cannot simultaneously detect visible and ultraviolet light with the same spatial resolution due to absorption issues and separate sensor regions, leading to inefficiencies and reliability concerns.

Innovation Solution

A single-chip semiconductor optical sensor with alternating UV and visible light detection cells, utilizing UV conversion regions and filter regions on a CMOS substrate to convert UV light into visible light, allowing simultaneous detection with the same spatial resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a single-chip sensor integrates both UV and visible light detection, then area occupation and manufacturing costs are reduced, but UV detection performance deteriorates due to absorption losses in insulating layers and substrate

Engineering Contradiction:

Improvearea occupationVSAvoidUV detection performance

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The sensor chip is divided into two distinct detection regions: a first detection region for UV light and a second detection region for visible light. This segmentation allows each region to be optimized for its specific wavelength range, with the UV region positioned to minimize absorption losses while the visible region maintains standard detection capabilities.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent utilizes the spatial dimension by positioning the UV detection region and visible detection region at different locations on the sensor chip. The UV region is strategically placed to receive UV light incident at specific angles, while the visible region is positioned to optimize visible light detection, thereby resolving the absorption conflict through spatial separation.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If separate optical sensors are used for UV and visible light detection, then detection performance is optimized for each wavelength range, but device complexity and manufacturing costs increase

Engineering Contradiction:

Improvedetection performanceVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges UV detection and visible light detection into a single optical sensor chip with integrated processing circuitry. Both detection regions share common signal processing resources, readout circuits, and control logic, thereby reducing device complexity and manufacturing costs while maintaining optimized detection performance for each wavelength range.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The sensor chip is designed as a multi-functional device that can simultaneously detect both UV and visible light. The integrated architecture allows a single device to perform multiple detection functions, eliminating the need for separate sensors and reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If UV conversion coatings are applied to convert UV light to visible light, then UV detection capability is enhanced, but the spectral range and detection accuracy are compromised

Engineering Contradiction:

ImproveUV detection capabilityVSAvoidspectral range and detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

Instead of using UV conversion coatings that would compromise spectral information, the patent segments the detection regions spatially. The UV detection region directly detects UV photons, while the visible detection region detects visible photons, preserving the full spectral information without conversion losses.

Inventive Principle:

Principle #1Segmentation

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

Enables the reconstruction of a single image containing both visible and UV light information with the same spatial resolution, reducing area occupation and manufacturing costs while improving reliability and efficiency.

Implementation Method 1

use of layers of a suitable material, being able to convert UV light radiation into visible light radiation

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

absorption depth of UV light radiation is very small (a few nanometers), so that a portion of radiation is absorbed in the structure of the optical sensor

Methodology Applied

Scientific EffectOptical absorption: Absorption (EM radiation)

Data Source

PatentUS11581350B2Semiconductor optical sensor for visible and ultraviolet light detection and corresponding manufacturing process

Publication Date: 2023.02.14 LFOUNDRY

AI summary

A semiconductor optical sensor (1) is provided with: a substrate (2) integrating a plurality of photodetector active areas (4); and a CMOS layer stack (6) arranged on the substrate (2) and including a number of dielectric (6a) and conductive (6b) layers. UV conversion regions (10) are arranged above a number of first photodetector active areas (4) to convert UV light radiation into visible light radiation towards the first photodetector active areas (4), so that the first photodetector active areas (4) are designed to detect UV light radiation. In particular, the first photodetector active areas (4) are alternated to a number of second photodetector active areas (4), designed to detect visible light radiation, in an array (15) of photodetection units (16) of the optical sensor (1), defining a single image detection area (15′), sensitive to both UV and visible light radiation with a same spatial resolution.