Vertical Capacitor MEMS Pressure Sensor Design
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Solution Overview
Problem
Existing MEMS-based pressure sensors face challenges in downsizing while maintaining sensitivity, as reducing membrane thickness compromises sensitivity, and require complex methods for varying structures to accommodate different applications, occupying a significant chip surface area.
Innovation Solution
The method involves creating pressure-sensitive capacitive capacitor structures that extend perpendicularly to the substrate surface, reducing substrate space, enhancing sensitivity through lateral lithographic precision, and using a vacuum between capacitive structures to improve mechanical stability, allowing for energy-efficient and versatile pressure measurement across various ranges without altering spatial dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If membrane thickness is reduced to downsize pressure sensors, then chip surface area is reduced, but sensitivity is compromised
Solution Approach 1:
The patent transitions from planar parallel detection structures occupying chip surface area to three-dimensional vertical capacitor structures extending perpendicular to the substrate. This dimensional change allows the sensing element to occupy minimal chip surface area while maintaining sufficient detection volume and sensitivity through vertical extension, directly resolving the contradiction between downsizing and sensitivity preservation.
2Area of moving object
If membrane thickness is reduced, then space is saved, but manufacturing difficulty increases
Solution Approach 1:
By forming capacitor structures that extend vertically through multiple substrate layers rather than creating ultra-thin membranes, the patent achieves space savings while using standard semiconductor fabrication processes (trench formation, layer deposition, patterning) that are well-established and manufacturable, avoiding the difficulties of producing and handling extremely thin membranes.
3Adaptability or versatility
If pressure sensor structures are varied for different applications, then application-specific performance is improved, but device complexity and cost increase
Solution Approach 1:
The patent creates a universal vertical capacitor structure platform that can measure different pressure ranges by varying electrical parameters (capacitor geometry, electrode configuration, readout circuitry) rather than requiring different physical structures for each application. This single structural design achieves multi-functionality across broad application spectra, reducing complexity and cost while maintaining application-specific performance.
4Stability of the object's composition
If vacuum is introduced between capacitive structures, then mechanical stability is improved, but manufacturing complexity increases
Solution Approach 1:
The vertical capacitor structure design naturally creates sealed cavities between stacked capacitor elements, allowing vacuum introduction to provide mechanical stability without requiring complex external sealing mechanisms. The vertical stacking geometry inherently defines the vacuum chamber boundaries, simplifying the overall manufacturing process compared to creating sealed vacuum chambers in planar configurations.
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 results in a compact, sensitive, and energy-efficient micromechanical pressure sensor device that can measure different pressure ranges without changing its spatial dimensions, providing stability against mechanical stress and simplifying manufacturing processes.
Implementation Method 1
capacitive structures and/or membranes which run in parallel to a chip front side
Implementation Method 2
pressure-sensitive capacitive capacitor structures
Data Source
AI summary
A manufacturing method for a micromechanical sensor device and a corresponding micromechanical sensor device. The method includes providing a substrate including at least one first through a fourth parallel trenches; depositing a layer onto the front side, the trenches being sealed, and structuring the layer, contact structures being formed in the layer above the second and fourth trenches; oxidizing of outwardly free-standing side surfaces of the contact structures as well as of the second and fourth trenches, at least in areas; depositing and structuring a first metallic contacting material, the contact structures being filled with the first metallic contacting material, at least in areas; opening the second trench and the fourth trench; galvanic deposition of a second metallic contacting material into the second and fourth trenches, resulting in the formation of a pressure-sensitive capacitive capacitor structure; and opening the first trench from the front side of the substrate.