Mechanical property evaluation and fracture behavior analysis of brittle thin films

Abstract

Two methods, top down and bottom up, exist in fabricating brittle thin films. The essence in determining the mechanical properties of brittle thin films are effect of size and direction which is included in single crystal material for top down method and deposition temperature for bottom up method. Direct tensile tests were performed on silicon thin films of 10, 20 50, $100 \mu m$ in thickness, which was fabricated by thinning technology of grinding the single crystal silicon wafer, in order to determine the size effect on the mechanical properties of thin brittle films. In addition, changes of mechanical properties with various directions such as <110>, <320>, <210>, and <100> are also investigated. Furthermore, deposition temperature was set to 80, 100, 150, 200, and $250^\circ C$ and tensile test was executed on the water surface for aluminum oxide thin film of 140nm in thickness, which was fabricated using ALD, in order to identify the effect of deposition temperature on mechanical properties of thin films. Therefore, the purpose of this particular research is to examine the influence of size, direction and deposition temperature on the mechanical properties of thin films.