Work

Release of hydrogen gas from PECVD silicon nitride thin films in cavities of MEMS sensors

Year: 2024

Type: article

Abstract: In this work we investigate the release of hydrogen gas from PECVD silicon nitride thin films in the cavities of MEMS based inertial sensors . Firstly, material characterization is conducted on two types of PECVD silicon nitride thin films to study the release of hydrogen gas with analytical methods. The release of hydrogen gas from these materials in encapsulated cavities of MEMS sensors, and its influence on the cavity pressure is also investigated experimentally with the help of functional microchips of MEMS based inertial sensors. Based on our findings and reports from other works, we propose steps by which change in the cavity pressure of the investigated microchip occurs over its different fabrication processes. We suggest that hydrogen gas is released form PECVD silicon nitride thin films at high temperatures during wafer bonding , which can then diffuse in cavities at low pressure over the lifetime of the sensor.

Source: Micro and Nano Engineering

DOI: 10.1016/j.mne.2024.100291

Authors: P. Dani, M. Tuchen, B.E. Meli, J. Franz, J. Knoch

Institutions: Robert Bosch (Germany), RWTH Aachen University

Language: English

Topic: Advanced MEMS and NEMS Technologies

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,780

Funders: Bundesministerium für Bildung und Forschung, Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie