Joule-assisted silicidation for short-channel silicon nanowire devices

We report on a technique enabling electrical control of the contact silicidation process in silicon nanowire devices. Undoped silicon nanowires were contacted by pairs of nickel electrodes and each contact was selectively silicided by means of the Joule effect. By a realtime monitoring of the nanowire electrical resistance during the contact silicidation process we were able to fabricate nickel-silicide/silicon/nickel- silicide devices with controlled silicon channel length down to 8 nm.Comment: 6 pages, 4 figure

High density germanium nanowire growth directly from copper foil by self induced solid seeding

Herein, we describe the growth of highly dense germanium nanowire mats directly on copper foil by a self induced, solid seeded protocol. The existence of Cu3Ge tips on each of the nanowires indicates that growth proceeds via a solid catalyzed route, dependent on the in situ formation of the germanide intermediate. The nanowires show a tight diameter distribution and typically growth directions resulting from similarities in the d-spacings between the nanowire and the catalyst seed. The nanowires and substrates were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD) scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX) and electron backscatter diffraction (EBSD)

Abrupt Schottky Junctions in Al/Ge Nanowire Heterostructures

International audienceIn this Letter we report on the exploration of axial metal/semiconductor (Al/Ge) nanowire heterostructures with abrupt interfaces. The formation process is enabled by a thermal induced exchange reaction between the vapor-liquid-solid grown Ge nanowire and Al contact pads due to the substantially different diffusion behavior of Ge in Al and vice versa. Temperature-dependent I-V measurements revealed the metallic properties of the crystalline Al nanowire segments with a maximum current carrying capacity of about 0.8 MA/cm(2). Transmission electron microscopy (TEM) characterization has confirmed both the composition and crystalline nature of the pure Al nanowire segments. A very sharp interface between the (111) oriented Ge nanowire and the reacted Al part was observed with a Schottky barrier height of 361 meV. To demonstrate the potential of this approach, a monolithic Al/Ge/Al heterostructure Was used to fabricate a novel impact ionization device