Nano Archive

Customizable in situ TEM devices fabricated in freestanding membranes by focused ion beam milling

Lei, Anders and Petersen, Dirch Hjorth and Booth, Timothy John and Homann, Lasse Vinther and Kallesoe, Christian and Sukas, OzlemSardan and Gyrsting, Yvonne and Molhave, Kristian and Boggild, Peter (2010) Customizable in situ TEM devices fabricated in freestanding membranes by focused ion beam milling. Nanotechnology, 21 (40). p. 405304.

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Official URL: http://stacks.iop.org/0957-4484/21/i=40/a=405304

Abstract

Nano- and microelectromechanical structures for in situ operation in a transmission electron microscope (TEM) were fabricated with a turnaround time of 20 min and a resolution better than 100 nm. The structures are defined by focused ion beam (FIB) milling in 135 nm thin membranes of single crystalline silicon extending over the edge of a pre-fabricated silicon microchip. Four-terminal resistance measurements of FIB-defined nanowires showed at least two orders of magnitude increase in resistivity compared to bulk. We show that the initial high resistance is due to amorphization of silicon, and that current annealing recrystallizes the structure, causing the electrical properties to partly recover to the pristine bulk resistivity. In situ imaging of the annealing process revealed both continuous and abrupt changes in the crystal structure, accompanied by instant changes of the electrical conductivity. The membrane structures provide a simple way to design electron-transparent nanodevices with high local temperature gradients within the field of view of the TEM, allowing detailed studies of surface diffusion processes. We show two examples of heat-induced coarsening of gold on a narrow freestanding bridge, where local temperature gradients are controlled via the electrical current paths. The separation of device processing into a one-time batch-level fabrication of identical, generic membrane templates, and subsequent device-specific customization by FIB milling, provides unparalleled freedom in device layout combined with very short effective fabrication time. This approach significantly speeds up prototyping of nanodevices such as resonators, actuators, sensors and scanning probes with state-of-art resolution.

Item Type:Article
ID Code:11194
Deposited By:Prof. Alexey Ivanov
Deposited On:01 Nov 2011 23:26
Last Modified:02 Nov 2011 00:47

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