Integrated Circuit with Dual-Function Polymer Sensor Layer
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Solution Overview
Problem
Current integrated circuits (ICs) with multiple light and gas sensors are bulky and expensive due to the complexity of manufacturing multiple discrete sensors, which complicates the integration of light sensors sensitive to different parts of the electromagnetic spectrum and increases production costs.
Innovation Solution
A compact IC design that incorporates a substrate with light sensors and a passivation layer, where a gas-sensitive material acts as both a moisture sensor and a filter for the light sensor, using polymers like polyimide or polyacetylenes with tunable absorption properties, allowing for a single processing step and reduced manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple discrete sensors are used to detect different parts of the electromagnetic spectrum, then the detection capability is improved, but the device size and manufacturing complexity increase
Solution Approach 1:
The patent combines multiple sensor functions into a single integrated device by integrating a photodiode for light detection with a polymer layer that serves dual purposes: as a gas-sensitive layer for moisture detection and as an optical filter for spectral selection. This merging eliminates the need for multiple discrete sensors and their associated complex manufacturing processes.
Solution Approach 2:
The polymer layer performs multiple functions simultaneously: it acts as a gas-sensitive layer for moisture sensing, an optical filter for wavelength selection, and a protective layer. This multi-functionality reduces the overall device complexity while maintaining comprehensive detection capabilities across different parts of the electromagnetic spectrum.
2Adaptability or versatility
If multiple discrete sensors are integrated into a single IC, then the detection versatility is improved, but the production cost increases
Solution Approach 1:
The invention merges multiple sensor functions into a single integrated circuit by depositing a polymer layer that simultaneously provides gas sensing and optical filtering capabilities. This approach eliminates the need for multiple discrete sensors and reduces production costs by simplifying the manufacturing process to a single integration step.
Solution Approach 2:
The patent utilizes the ability to change the optical and gas-sensitive properties of the polymer layer by selecting different polymer materials and controlling deposition parameters. This allows tuning of the sensor characteristics to detect different parts of the electromagnetic spectrum without requiring additional discrete sensors, thereby reducing production costs while maintaining detection versatility.
3Adaptability or versatility
If standard photodiodes are used for light sensing, then the detection range is improved, but the wavelength selectivity deteriorates
Solution Approach 1:
The patent employs a composite structure where a polymer layer with specific optical and gas-sensitive properties is integrated with a photodiode. This composite material approach provides both broad detection range through the photodiode and wavelength selectivity through the polymer layer's optical filtering properties, resolving the contradiction between detection range and wavelength selectivity.
Solution Approach 2:
The polymer layer is applied selectively over the photodiode surface, creating local optical filtering properties in specific regions. This allows different areas of the sensor to be optimized for different wavelengths, providing wavelength selectivity while maintaining the overall detection range of the photodiode.
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 a cost-effective, compact IC that can detect various environmental parameters, including light and moisture levels, with improved spectral selectivity and reduced production costs, suitable for applications in electronic devices and packaged items.
Implementation Method 1
a gas sensitive layer in between a first electrode and a second electrode, the gas sensitive layer further comprising a portion over the first area
Implementation Method 2
the gas sensitive layer further comprising a portion over the first area
Implementation Method 3
The light is absorbed in Si substrate by generating electron-hole pairs near the depletion region of a typically reversed-biased n+/p (or p+/n) diodes, these carriers are separated by the depletion region and as a result generate photo-current that can be measured
Implementation Method 4
using polymers like polyimide or polyacetylenes with tunable absorption properties
Data Source
AI summary
Disclosed is an integrated circuit comprising a substrate including at least one light sensor; an interconnect structure over the substrate; at least one passivation layer over the interconnect structure, said passivation layer including a first area over the at least one light sensor; and a gas sensor such as a moisture sensor at least partially on a further area of the at least one passivation layer, wherein the gas sensor comprises a gas sensitive layer in between a first electrode and a second electrode, the gas sensitive layer further comprising a portion over the first area. A method of manufacturing such an IC is also disclosed.