FIB -CVDによるマイクロ構造体の作製と機械的性質の評価

Abstract

Three dimensional micro structures fabricated by focused ion beam chemical vapor deposition (FIB-CVD) are expected to be the structural materials for MEMS/NEMS. In this research, the micro structures with square shape were fabricated by FIB-CVD with different probe currents of 48, 200, 1300, 5200 pA, and Vickers hardness tests of the micro structures were carried out. The Vickers hardness tests revealed that hardness of the micro structures depends on the probe current density. As a result of cross-sectional TEM observations, it was found that the micro structure has amorphous phase. Mechanical properties of the micro structure with beam shape were investigated by bending test. As a result of the bending tests, Young's modulus of a beam shaped structure was about 20 GPa Furthermore, macro SEM observation of the beam shaped structure after failure revealed that brittle fracture occurred and the fracture stress was 2.2±0.1 GPa SEM-EDS images revealed that 94% carbon and 6% gallium composes micro structure and the composition of micro structure was homogeneous.