Journal of Micromechanics and Microengineering · 2007 · 99 citations · 22 references
Natural SciencesMaterials EngineeringMaterials ScienceMaterials CharacterizationMechanical Behavior Of MaterialsThin FilmsDislocation MechanicsDislocation TheoryFracture MechanicsFracture ToughnessSilicon MaterialsThin Film Mechanical PropertiesDislocation BehaviorFracture Toughness MeasurementLow-temperature MaterialsSiliconSilicon Thin FilmsSingle-crystal SiliconThermomechanical FractureThermomechanical Stress
A change in the fracture mode of a micrometer-sized single-crystal-silicon (SCS) film was observed at a temperature slightly higher than room temperature (RT). Silicon films with a notch on one side were tested under tensile stress at temperatures ranging from RT to 500 °C. The mean fracture toughness was 1.28 MPa at RT and the value remained similar up to 60 °C. However, it drastically increased to nearly twice this value above 70 °C. Differences in the fracture mode and dislocation activity were found by scanning and transmission electron microscopy (SEM and TEM). These results show that the fracture mode changed even at a low temperature near 70 °C due to the activation of dislocations at the notch tip.
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