Determination of SiO2 Mechanical Behavior Via High Temperature Microtensile Testing
Final progress rept. 1 Jul-31 Dec 2001
LEHIGH UNIV BETHLEHEM PA
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The goal of this STIR project was to develop and demonstrate the capability to carry out the first direct determination of the mechanical properties of SiO2 thin films at typical oxidation temperatures and stresses. There is little doubt that time-dependent inelastic deformation plays a significant role in SiO2 films. There are various ways of obtaining mechanical properties data, but the most direct and the least ambiguous in interpretation is testing under uniaxial loading. Unfortunately testing specimens of bulk vitreous SiO2 is not sufficient because this material is believed to have mechanical properties that differ from those of thermally grown SiO2. Our approach was to conduct tensile tests on microscopic specimens of thermally grown SiO2 from which the silicon substrate has been chemically removed. The four stages of the project were to fabricate thin SiO2 specimens, to test the specimens at room temperature, to demonstrate a high temperature furnace compatible with the tensile tester, and to acquire a demonstration measurement of the high temperature mechanical behavior of SiO2. The first three stages of the project were successfully completed. The fourth stage, demonstration of high temperature measurement, was attempted but could not be completed within the time frame of the project.
- Physical Chemistry
- Solid State Physics