Fatigue test of thin film materials on a silicon chip using resonating loading system

Abstract

We investigated a new method of measuring fatigue characteristics of thin films under uniaxial loading conditions. A specimen and loading system are integrated on a same silicon ship. The size of the chip is 12 by 12 by 0.4 mm, and of the specimen 400 by 80 by 7 micrometers . Accuracy of the stress and strain measurement using the proposed loading system was proved by our previous work under static conditions. In this paper, high frequency of tensile stress was applied to the specimen by resonant mode of vibration of the loading mechanism. The loading system vibrated at the first mode resonant frequency. To vibrate the loading system, the chip was mounted on a PZT actuator, and driven by a pulse generator. The amplitude of the applied strain was measured by observing a laser reflection on the vibrating lever of the loading system, while the wave from and the vibration cycle were monitoring by an oscilloscope. The resonant frequency of the chip was 4-5 kHz.