Stressed Decoupled MEMS Sensor With Sealed Trenches
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Solution Overview
Problem
Existing MEMS sensors are vulnerable to environmental conditions such as humidity, temperature changes, and chemical substances due to open trenches used for stress decoupling, which can lead to damage and reduced performance, especially in harsh applications like automotive environments.
Innovation Solution
A stress decoupling structure with trenches is combined with a sealing element, such as a cap or gel, to partially decouple the sensor region from the non-sensor region, effectively sealing the openings and protecting the MEMS sensor from environmental factors, allowing for robust performance in harsh conditions while maintaining cost-effectiveness and miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If open trenches are used for stress decoupling, then stress decoupling effectiveness is improved, but vulnerability to environmental conditions (humidity, temperature changes, chemical substances) worsens
Solution Approach 1:
The device is segmented into a sensor region and a non-sensor region using trenches. The trenches physically divide the semiconductor device structure, creating separate functional zones. This segmentation allows the sensor region to be isolated from environmental factors while maintaining stress decoupling functionality through the trench structure itself.
Solution Approach 2:
A sealing element is introduced as an intermediary component that fills the trenches and seals the sensor region. This sealing element acts as a mediator between the sensor region and the external environment, blocking harmful environmental factors (humidity, chemicals, temperature extremes) from penetrating into the sensor region while allowing the stress decoupling function to persist through the sealed trench structure.
2Reliability
If sealing element is added to protect from environmental factors, then robustness against environmental conditions is improved, but device complexity worsens
Solution Approach 1:
The sealing element functions as a protective shell or film that covers and seals the trench openings. This thin-film or shell-like structure provides environmental protection without adding significant bulk or complexity to the device. The sealing element conformally follows the trench geometry, creating an integrated protective layer that is structurally efficient.
Solution Approach 2:
The sealing element is integrated into the existing trench structure rather than being a separate additive component. The sealing process merges the protection function with the existing stress decoupling structure, combining multiple functions (stress decoupling + environmental sealing) into a unified structural solution that minimizes overall device complexity.
3Reliability
If sensor region is decoupled from non-sensor region, then MEMS performance is improved, but penetration of trenches by environmental factors worsens
Solution Approach 1:
The harmful penetration pathway is extracted or removed from the device structure by filling and sealing the trenches. The sealing element extracts the vulnerability associated with open trenches while preserving the beneficial stress decoupling geometry. This extraction of the harmful aspect (open access to environment) leaves the useful aspect (stress decoupling structure) intact.
Data Source
AI summary
A semiconductor device may include a stress decoupling structure to at least partially decouple a first region of the semiconductor device and a second region of the semiconductor device. The stress decoupling structure may include a set of trenches that are substantially perpendicular to a main surface of the semiconductor device. The first region may include a micro-electro-mechanical (MEMS) structure. The semiconductor device may include a sealing element to at least partially seal openings of the stress decoupling structure.