New methods for measuring mechanical properties of thin films in micromachining: Beam pull-in voltage (VPI) method and long beam deflection (LBD) method

doi:10.1016/0924-4247(95)00987-6

Sensors and Actuators A: Physical

Volume 48, Issue 2, 15 May 1995, Pages 137-143

https://doi.org/10.1016/0924-4247(95)00987-6 Get rights and content

Abstract

New stress-measurement methods for determining both tensile and compressive stress and Young's modulus in surface micromachining are presented. The investigation is concentrated on the development of two techniques: (1) beam pull-in voltage (V_PI) and (2) long beam deflection (LBD). The V_PI method is based on the pulling down of the upper electrode (beam) when the voltage between two electrodes exceeds a critical level. Both tensile and compressive stress and Young's modulus of a thin film can be derived using this method. the LBD method, on the other hand, converts the axial strain in the beam into a transverse deflection w(x) after the structure is released to be free standing; this deflection is large enough to be measured easily. These techniques have been analysed and tested experimentally. A comparison with other known stress-measurement techniques shows good agreement using polysilicon films. Both techniques have been shown to be quite promising for simple and accurate on-chip thin-film stress measurements.

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Citation Excerpt :
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Sensors and Actuators A: Physical

Abstract

References (8)

Mechanical property measurement of composite rectangular membrane

Sensor and Actuator

Measurement of the mechanical properties of silicon microresonators

Sensors and Actuators A

Static and dynamic aspects of an air-gap capacitor

Sensors and Actuators A

Study of fabrication process of a micro electrostatic switch and its application to a micromechanical V–F converter

Sensors and Actuators A

Cited by (65)

Size effect on pull-in behavior of electrostatically actuated microbeams based on a modified couple stress theory

Pull-in characterization of doubly-clamped composite beams

Design and fabrication of a new MEMS capacitive microphone using a perforated aluminum diaphragm

Determination of compressive residual stress in a doubly-clamped microbeam according to its buckled shape

8.09 - MEMS Structures for On-chip Testing of Mechanical and Surface Properties of Thin Films

Buckling shape of elastically constrained multi-layered micro-bridges