MICROFABRICATION OF INTEGRATED SCANNING TUNNELING MICROSCOPE

An integrated circuit-compatible process has been demonstrated for microfabricating arrays of scanning tunneling microscopes on silicon wafers. Each microfabricated scanning tunneling microscope (STM) incorporates a novel three-dimensional thin-film piezoelectric actuator which is capable of scanning the STM tip laterally over the sample surface and following surface topography. The actuator is in the form of a cantilever bimorph constructed from alternating layers of multiple metallic electrodes, dielectric films, and piezoelectric zinc oxide films. Each device is designed to scan a region 0.1X 1 μm with low voltage drive, with a maximum vertical deflection of 15 μm, which simplifies sample approach. The dimensions of the device are 1000x200x8 μm. Operation of the device has been demonstrated by imaging graphite with atomic resolution. The piezoelectric actuator in this device is itself a significant contribution to the field of microactuators, with many non-STM applications. © 1990, American Vacuum Society. All rights reserved.