A micromachined tunneling current device for the direct observation of the tunneling gap

Abstract

Describes the application of micromachine technology to fabricate nanoscale structures for the observation of quantum phenomena, such as atomic motion and electron transport in molecules, tunneling gaps and quantum nanowires. An ultra-high resolution TEM (transmission electron microscope) visualizes the tunneling gap or the nanowires and gives direct information about the geometries, motion and electromagnetic field distribution with atomic-level resolution. The TEM, which is under development, is expected to resolve a single atom because it detects the phase shift of electron waves by electron interferometry. A micromachine scanning tunneling microscope (micro-STM) is placed in the TEM to control the tunneling current. An overview of the project, the micromachining process for fabricating nanowires with microactuators, and some fabrication results are described. We made a nanowire with a triangular cross-section of 80 nm in side-length and 5 /spl mu/m in length successfully. The wire was overhanging the edge of an observation aperture. The wire was integrated with a rigid microactuator in order to complete a micro-tunneling current device.