  Transmission electron beams (TEBs) have long been used to study and
manipulate materials at nanometer scales. In the late 1970's, Cherns
demonstrated surface pitting in Au films upon exposure to a 1MeV TEB and
observed crystal dislocations in quartz. Soon after, electron beam irradiation
was used to drill nanoholes and lines in NaCl crystals, alumina sheets, CaF2
and MgO. More recent examples include the drilling of nanoholes in silicon,
stainless steel, and in Si3N4 and SiO2 membranes. In this Letter we demonstrate
a new and highly flexible application of TEB-based fabrication to produce
intricate metal geometries and fully integrated devices, with sub-10 nm
features, on silicon nitride membranes. Arbitrary metal patterns may be "carved
out" with sub-nanometer accuracy by ablating evaporated (Al, Ni, Cr, Ag, Au)
metal films with the ~ 0.5 nm diameter beam of a high resolution transmission
electron microscope. In situ imaging of the ablation action allows for
real-time feedback control. Specific examples presented here include nanorings,
nanowires with tailored curvatures and multi-terminal devices with nanoislands
or nanoholes between the terminals. Importantly, these nanostructures are
fabricated at precise locations on a chip and seamlessly integrated into
large-scale circuitry. The combination of high resolution, geometrical control
and yield make this fabrication method rather unique and highly attractive for
many applications including nanoelectronics and molecular translocation.
