Uncooled Infrared Sensor Reference Pixel Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Uncooled infrared image sensors face challenges in performing accurate temperature corrections due to differences in I-V characteristics between pixel units and reference pixel units, leading to suboptimal sensitivity and image quality.
Innovation Solution
The design incorporates reference pixel units with the same I-V characteristics as pixel units by forming interconnect units with matching electrical resistance and concave portions below them, ensuring consistent heat conductance and signal generation, allowing for precise temperature corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reference pixel units are placed in the vicinities of pixel units to perform temperature corrections, then temperature correction capability is provided, but measurement precision deteriorates due to different I-V characteristics between reference pixel units and pixel units
Solution Approach 1:
The invention introduces a specific structural modification to the reference pixel units: forming concave portions in the substrate below the reference pixel units, identical to those in pixel units. This local structural change ensures that reference pixel units have the same I-V characteristics as pixel units, enabling accurate temperature corrections. The concave portions create thermal isolation that matches the thermal environment of pixel units, resolving the measurement precision issue while maintaining temperature correction capability.
Solution Approach 2:
The invention changes the physical structure of the substrate by forming concave portions below reference pixel units, which alters the thermal conduction parameters. This structural parameter change ensures that reference pixel units experience the same thermal conditions as pixel units, making their I-V characteristics identical and enabling precise temperature measurements and corrections.
2Reliability
If concave portions are formed below pixel units to increase sensitivity, then sensitivity is improved, but device complexity increases due to additional substrate modification
Solution Approach 1:
The invention makes the concave portion structure universal by applying it to both pixel units and reference pixel units. This multi-functional application ensures that both types of units have identical I-V characteristics and thermal environments. The same structural feature serves dual purposes: maintaining pixel unit sensitivity and enabling reference pixel units to provide accurate temperature corrections.
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 approach enables more accurate temperature corrections and improved sensitivity in uncooled infrared image sensors by ensuring that pixel and reference pixel units have matching I-V characteristics, enhancing the overall performance and accuracy of temperature measurements.
Implementation Method 1
a first infrared absorption film absorbing an incident infrared ray and converting the absorbed infrared ray into heat
Implementation Method 2
a first heat sensitive element generating an electrical signal by detecting the heat from the first infrared absorption film
Data Source
AI summary
An uncooled infrared image sensor according to an embodiments includes: a plurality of pixel cells formed in a first region on a semiconductor substrate; a reference pixel cell formed in a second region on the semiconductor substrate and corresponding to each row or each column of the pixel cells; a supporting unit formed for each of the pixel cell and supporting a corresponding pixel cell; and an interconnect unit formed for each reference pixel cell. Each of the pixel cells includes: a first infrared absorption film and a first heat sensitive element. The reference pixel cell includes: a second infrared absorption film and a second heat sensitive element, the second heat sensitive element having the same characteristics as characteristics of the first heat sensitive element. The third and fourth interconnects of the interconnect unit have the same electrical resistance as electrical resistance of the first and second interconnects of the supporting unit.