Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Biaxial testing of nanoscale films on compliant substrates: Fatigue and fracture

Summary: Biaxial testing of nanoscale films on compliant substrates:
Fatigue and fracture
B. Erdem Alaca,a)
John C. Selby, M. T. A. Saif, and Huseyin Sehitoglu
Department of Mechanical and Industrial Engineering, University of Illinois, 1206 West Green Street,
Urbana, Illinois 61801
Received 6 November 2001; accepted for publication 6 May 2002
Two problems of technological importance for microelectromechanical systems MEMS and
microelectronics industry are addressed: fatigue of thin films and nanoscale film cracking. A device
is described that can 1 conduct biaxial fatigue tests on thin films and 2 be utilized to study
fracture patterns in nanoscale coatings under biaxial stress state. Thin-film specimens, in the form
of circular membranes, are exposed to cyclic pressures between two fixed pressure limits.
Corresponding pressure and specimen deflection are measured. Experimental results, including
hysteresis loops spanning deflections of 1550 m are presented for 4.6- m-thick polyimide films.
Furthermore, the evolution of crack patterns in a 150-nm-thick Al film deposited on a polyimide
substrate is studied. Critical mode I stress intensity factor for Al is extracted from experimental
results. 2002 American Institute of Physics. DOI: 10.1063/1.1488685
Evaluation of mechanical properties of thin films has
attracted much attention due to the important role thin films


Source: Alaca, B. Erdem - Department of Mechanical Engineering, Koc University


Collections: Engineering