How to Build a Tiny Pressure Sensor Inside a Silicon Chip
This patent describes a method for building a tiny pressure sensor, called a MEMS sensor, directly inside a silicon chip, where a flexible membrane and a plate form a capacitor that changes with pressure.
Original patent title: “Process for manufacturing a MEMS pressure sensor, and corresponding MEMS pressure sensor”
This patent describes a method for building a tiny pressure sensor, called a MEMS sensor, directly inside a silicon chip, where a flexible membrane and a plate form a capacitor that changes with pressure. Granted to STMicroelectronics SRL in 2020 with 23 claims and 1 forward citation, and it is expected to expire in 2038.
Coverage
What does this patent actually cover?
This patent details a process for manufacturing a MEMS pressure sensor. It starts by creating a 'buried cavity' entirely within a silicon substrate (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1). A 'membrane' is then suspended above this cavity (Claim 1). Next, a 'conductive layer comprising a plate' made of polysilicon is formed above the membrane, separated by an 'empty space' (Claim 1). This empty space is created by growing the polysilicon layer on a temporary 'sacrificial layer,' then etching 'through holes' in the polysilicon and removing the sacrificial material through these holes (Claim 1). An 'access channel' is formed to allow outside air pressure to reach the membrane (Claim 1). Finally, 'electrical-contact elements' are created to connect to the membrane and the plate, which together form a 'sensing capacitor' whose electrical capacitance changes as pressure flexes the membrane (Claim 1). For example, a smartphone might use such a sensor to detect changes in altitude by measuring atmospheric pressure.
The gap
What does this patent NOT cover?
- Does not cover pressure sensors that do not rely on changes in capacitance (e.g., piezoresistive sensors).
- Does not cover sensors where the cavity is not 'fully enclosed buried within the body' of the semiconductor material (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 8).
- Does not cover manufacturing processes that do not use a sacrificial layer and through-holes to create the empty space between the membrane and the plate (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover sensors where the suspended plate is not made of polysilicon (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1, 8).
- Does not cover sensors where the fluidic communication to the membrane is not provided by 'a plurality of through holes in the layer of polysilicon' (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 8).
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The cleverness lies in the specific sequence of microfabrication steps that create a fully integrated, buried capacitive pressure sensor. This includes forming the cavity and membrane *inside* the silicon, then precisely creating the polysilicon plate and its empty space using a sacrificial layer and through-holes, and finally integrating the electrical contacts for the sensing capacitor, all within the chip.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Smartphones (for altitude and weather sensing)
Smartwatches (for activity tracking and elevation)
Drones (for stable flight and altitude hold)
Automotive tire pressure monitoring systems (TPMS)
Medical devices (e.g., blood pressure monitors)
Industrial process control systems
Why it matters
The bigger picture
MEMS pressure sensors are essential components in a vast array of modern devices, enabling functions from precise altitude measurement in drones to tire pressure monitoring in cars. This patent's manufacturing process aims to improve the integration and performance of these tiny sensors. STMicroelectronics, the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is a significant global supplier of MEMS devices, making advancements in their manufacturing processes commercially important.
Filed
April 20, 2018
Granted
March 3, 2020
Market context
Who's building on this
Companies in this space
STMicroelectronics, the original assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is a global leader in MEMS technology and continues to develop and manufacture a wide range of MEMS sensors, including pressure sensors. Other major semiconductor companies like Bosch, NXP Semiconductors, and Infineon also actively develop and produce MEMS pressure sensors, constantly refining their manufacturing processes.
Market impact
Advanced manufacturing processes like the one described in this patent contribute to the ongoing miniaturization, cost reduction, and performance improvement of MEMS pressure sensors. This enables their widespread adoption across various industries, creating new product categories and enhancing existing ones, from more accurate fitness trackers to safer automotive systems. Such innovations are critical for maintaining competitiveness in the high-volume MEMS market.
Claim 1 — Plain English
What this patent covers
This patent details a process for manufacturing a MEMS pressure sensor. It starts by creating a 'buried cavity' entirely within a silicon substrate (Claim 1). A 'membrane' is then suspended above this cavity (Claim 1). Next, a 'conductive layer comprising a plate' made of polysilicon is formed above the membrane, separated by an 'empty space' (Claim 1). This empty space is created by growing the polysilicon layer on a temporary 'sacrificial layer,' then etching 'through holes' in the polysilicon and removing the sacrificial material through these holes (Claim 1). An 'access channel' is formed to allow outside air pressure to reach the membrane (Claim 1). Finally, 'electrical-contact elements' are created to connect to the membrane and the plate, which together form a 'sensing capacitor' whose electrical capacitance changes as pressure flexes the membrane (Claim 1). For example, a smartphone might use such a sensor to detect changes in altitude by measuring atmospheric pressure.
The clever bit
The cleverness lies in the specific sequence of microfabrication steps that create a fully integrated, buried capacitive pressure sensor. This includes forming the cavity and membrane *inside* the silicon, then precisely creating the polysilicon plate and its empty space using a sacrificial layer and through-holes, and finally integrating the electrical contacts for the sensing capacitor, all within the chip.
What it does not cover
- Does not cover pressure sensors that do not rely on changes in capacitance (e.g., piezoresistive sensors).
- Does not cover sensors where the cavity is not 'fully enclosed buried within the body' of the semiconductor material (Claim 8).
- Does not cover manufacturing processes that do not use a sacrificial layer and through-holes to create the empty space between the membrane and the plate (Claim 1).
- Does not cover sensors where the suspended plate is not made of polysilicon (Claim 1, 8).
- Does not cover sensors where the fluidic communication to the membrane is not provided by 'a plurality of through holes in the layer of polysilicon' (Claim 8).
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
6/40
Early citations
Claim breadth
15/20
Broad claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
10/20
Granted 5–10 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$44K – $140K
Midpoint $88K · 11.7 yr remaining · industry ×0.9
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
23 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Zerbini, S., Duqi, E., & Baldo, L. (2020). How to Build a Tiny Pressure Sensor Inside a Silicon Chip (U.S. Patent No. 10,578,505). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/10578505/process-for-manufacturing-a-mems-pressure-sensor-and-corresponding-mems-pressure
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How to Build a Tiny Pressure Sensor Inside a Silicon Chip cover?
This patent describes a method for building a tiny pressure sensor, called a MEMS sensor, directly inside a silicon chip, where a flexible membrane and a plate form a capacitor that changes with pressure.
Who owns patent US 10578505?
STMicroelectronics SRL owns this patent, granted in 2020.
When does this patent expire?
This patent is expected to expire on April 20, 2038, when the invention enters the public domain.
What is patent US 10578505 cited by?
This patent has been cited by 1 later patents that build on its ideas.
What problem does this patent solve?
MEMS pressure sensors are essential components in a vast array of modern devices, enabling functions from precise altitude measurement in drones to tire pressure monitoring in cars. This patent's manufacturing process aims to improve the integration and performance of these tiny sensors. STMicroelectronics, the assignee, is a significant global supplier of MEMS devices, making advancements in their manufacturing processes commercially important.
What does this patent NOT cover?
Does not cover pressure sensors that do not rely on changes in capacitance (e.g., piezoresistive sensors).
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