A MEMS device for in-situ TEM test of SCS nanobeam

In-situ tensile testing in TEM (transmission electron microscopy) is a useful tool for studying mechanical properties of nano-structures because it can provide quantitative information on sample deformation at atomic scale. To facilitate in-situ TEM tensile tests of SCS (single crystal silicon) nanobeam, a MEMS tensile-testing chip was designed and fabricated. The chip was fabricated by means of bulk micromachining and wafer bonding techniques. An SCS nanobeam, a comb drive actuator, a force sensor beam and an electron beam window were integrated into the chip. With the on-chip comb-drive-actuator stretching the nanobeam and in-situ TEM observation, tensile test on a 90 nm-thick nanobeam was performed and the strain-stress relationship was obtained. The Young’s modulus was fitted to be 161 GPa and did not show the size effect. Supported by the National Basic Research (973 Program) (Grant No. 2006CB300406)