Two-Wavelength Infrared Detection Device With Intermediate Electrodes

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Solution Overview

Problem

Two-wavelength infrared detection devices using bulk mixed crystals face reduced sensitivity due to crystal defects in metamorphic buffer layers, which impede accurate detection of infrared rays across different wavelength bands.

Innovation Solution

A two-wavelength infrared detection device structure is designed with a specific metamorphic buffer layer configuration and electrode layout that allows photo carriers from both infrared absorption layers to reach the intermediate electrode without passing through the defective buffer layer, ensuring accurate measurement of infrared ray intensity across middle and far infrared wavelengths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a metamorphic buffer layer is formed between infrared absorption layers to enable two-wavelength detection with bulk mixed crystals, then the device can detect both middle and far infrared wavelengths, but the crystal defects in the buffer layer reduce detection sensitivity

Engineering Contradiction:

Improvedetection wavelength rangeVSAvoiddetection sensitivity

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The device is divided into two separate detection units: a first detection unit for middle infrared wavelengths and a second detection unit for far infrared wavelengths. Each unit has its own infrared absorption layer and contact layers, allowing independent optimization and preventing cross-interference through the defective buffer layer

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the device are designed with different structures optimized for their specific wavelength bands. The first infrared absorption layer uses InAsSb with higher Sb composition for middle infrared, while the second uses InAsSb with lower Sb composition for far infrared, with each region having tailored contact layers and electrodes

Inventive Principle:

Principle #3Local quality

2Device complexity

If carriers pass through the metamorphic buffer layer to reach electrodes, then the device structure remains simple, but carrier trapping in the buffer layer reduces detection sensitivity

Engineering Contradiction:

Improvedevice structureVSAvoiddetection sensitivity

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The harmful effect of the defective buffer layer is eliminated by extracting carriers from the path through the buffer layer. Intermediate electrodes are introduced to collect carriers directly from each infrared absorption layer before they can traverse the defective buffer layer region

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Intermediate electrodes serve as intermediary collection points for photo carriers generated in each infrared absorption layer. These electrodes collect carriers locally and transmit signals through separate paths, preventing carrier trapping in the buffer layer while maintaining structural organization

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances the detection sensitivity by preventing carrier trapping in the metamorphic buffer layer, allowing for accurate measurement of infrared rays across both wavelength bands without sensitivity loss.

Implementation Method 1

infrared absorption layers are formed with InAsSb bulk mixed crystals

Methodology Applied

Scientific EffectPhoto absorption: Absorption (EM radiation)

Data Source

PatentUS10741714B2Infrared detection device, infrared detection apparatus, and manufacturing method of infrared detection device

Publication Date: 2020.08.11 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An infrared detection device includes a semiconductor substrate; a first metamorphic buffer layer that is formed on the semiconductor substrate; a first contact layer that is formed on the first metamorphic buffer layer; a first infrared absorption layer that is formed on the first contact layer; a second contact layer that is formed on the first infrared absorption layer; a second metamorphic buffer layer that is formed on the second contact layer; a third contact layer that is formed on the second metamorphic buffer layer; a second infrared absorption layer that is formed on the third contact layer; a fourth contact layer that is formed on the second infrared absorption layer; a lower electrode that is connected with the first contact layer; an upper electrode that is connected with the fourth contact layer; and an intermediate electrode that is connected with the second contact layer and the third contact layer.