Integrated Ambit Light Sensor with IR Sensing

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Solution Overview

Problem

Ambit light sensors currently only sense light with a single wavelength, limiting their quantum efficiency and requiring additional filters for infrared sensing, which increases material and processing costs.

Innovation Solution

An integrated ambit light sensor with both visible and infrared sensing capabilities is fabricated using a substrate with a hydrogenated amorphous silicon structure and a dielectric layer, allowing for simultaneous sensing of different wavelengths without the need for additional filters, featuring a stacked hydrogenated amorphous silicon layer and transparent electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If additional filters are added for infrared sensing, then infrared sensing capability is improved, but material and processing costs increase

Engineering Contradiction:

Improveinfrared sensing capabilityVSAvoidmaterial and processing costs

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges the visible light sensing layer and infrared sensing layer into a single integrated sensor structure. The visible light sensing layer is positioned above the infrared sensing layer, allowing both functions to be combined in one device without requiring separate filters, thereby reducing material and processing costs while maintaining both sensing capabilities.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The sensor structure is designed to perform multiple functions: it can sense both visible light and infrared radiation simultaneously. The visible light sensing layer responds to visible wavelengths while the infrared sensing layer detects infrared wavelengths, creating a universal sensor that handles multiple spectral ranges without additional filters.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If separate filter fabrication is performed, then wavelength selectivity is improved, but layout area and fabrication budget increase

Engineering Contradiction:

Improvewavelength selectivityVSAvoidlayout area

Core Design Contradiction:

Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The patent combines wavelength selectivity functions directly into the sensing layers themselves rather than using separate filter components. The visible light sensing layer inherently selects visible wavelengths while the infrared sensing layer selects infrared wavelengths, eliminating the need for additional filter structures and reducing layout area.

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If single wavelength sensing is used, then device complexity is reduced, but quantum efficiency is limited

Engineering Contradiction:

Improvesensing structure simplicityVSAvoidquantum efficiency

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The sensor is segmented into two distinct functional layers: a visible light sensing layer and an infrared sensing layer. Each layer is optimized for its specific wavelength range, allowing both to operate at high quantum efficiency without interfering with each other. This segmentation maintains relative structural simplicity while dramatically improving overall quantum efficiency across different wavelengths.

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

The solution enables high quantum efficiency in visible light wavelengths while reducing material and processing costs by integrating infrared sensing on the same chip, saving layout area and eliminating the need for separate filter fabrication.

Implementation Method 1

The hydrogenated amorphous silicon layer is located on the lower electrode. The transparent upper electrode covers on the hydrogenated amorphous silicon layer.

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

The IR sensing structure is located in the substrate under the ambit light sensing structure and configured to sense IR

Methodology Applied

Scientific EffectInfrared radiation detection: Absorption (EM radiation)

Data Source

PatentUS8558177B2Ambit light sensor with function of IR sensing

Publication Date: 2013.10.15 POWERCHIP SEMICON MFG CORP

AI summary

An ambit light sensor with a function of IR sensing and a method of fabricating the same are provided. The ambit light sensor includes a substrate, an ambit light sensing structure, an infrared ray (IR) sensing structure, and a dielectric layer. The ambit light sensing structure is located over the substrate for sensing and filtering visible light. The IR sensing structure is located in the substrate under the ambit light sensing structure for sensing IR. The dielectric layer is located between the ambit light sensing structure and the IR sensing structure.