Measurement of Mechanical Strain based on Piezo-Avalanche Effect

Resource type
Date created
2019-05-13
Authors/Contributors
Abstract
We are reporting on the use of the breakdown voltage of a pn junction to measure mechanical strain in micro-structures. The working principle relies on the dependence of silicon band gap to the mechanical stress which affects the current-voltage characteristics of the pn junction. An analytic model is developed and verified experimentally for the phenomenon. A micromechanical device with integrated junctions was designed and fabricated. Mechanical stress was applied onto the structure by subjecting it to mechanical vibrations. It is shown that the breakdown voltage of the device exhibited a high stress sensitivity of about 240ߤ/ܸܯ .ܽܲ. The mechanical stress can also be measured by monitoring the device current while biased at a constant current. In this mode, the steep changes of the junction current in breakdown region led to nearly a tenfold higher stress sensitivity compared to a piezoresistive sensor. The high sensitivity, simple measurement, and potential for miniaturization for piezo-avalanche sensing make it a promising technique for measurement of stress in micro- and nano-mechanical devices.
Document
Published as
Perunnilathil Joy, Abbin, et al. “Measurement of Mechanical Strain Based on Piezo-Avalanche Effect.” Applied Physics Letters, vol. 114, no. 19, 2019, p. 192101. DOI: 10.1063/1.5093553
Publication title
Applied Physics Letters
Document title
Measurement of Mechanical Strain Based on Piezo-Avalanche Effect
Date
2019
Volume
114
Issue
19
First page
192101-1
Last page
192101-5
Publisher DOI
10.1063/1.5093553
Copyright statement
Copyright is held by the author(s).
Scholarly level
Peer reviewed?
Yes
Language
Member of collection