TEM observation of damage in aluminium thin films using
on-chip nanomechanical testing laboratory
M. Coulombier1,3, A. Boe2,3, S. Ryelandt1, J.P. Raskin2,3, T. Pardoen1,3
1
Institute of mechanical, materials and civil engineering,
Université catholique de Louvain, Louvain-la-Neuve, Belgium
2
Department of Electrical Engineering, Université catholique de Louvain
Louvain-la-Neuve, Belgium
3
CeRMiN, Research Center in Micro and Nanoscopic Materials and Electronic Devices,
Université catholique de Louvain, Louvain-la-Neuve, Belgium
E-mail: michael.coulombier@uclouvain.be,
A new concept of micromachines, based on classical MEMS technology, has been developed
for measuring the mechanical properties of thin metallic films. The actuator is a beam
undergoing large internal stresses built up during the deposition process. Al thin films are
deposited partly on the actuator beam and on the substrate. By etching the structure, the
actuator contracts and loads the Al film. Full stress strain curves can be generated by
designing a set of micromachines with various actuator/sample lengths ratios. In the present
study, the displacements have been measured by scanning electron microscopy. The stress is
derived from simple continuum mechanics relationships. Moreover, the damage mechanisms
have been observed in the Al films by TEM observations, using special preparation on the
specimen by micromachining with FIB.