Synthesized Aluminum Nanowires for Future Interconnects [Nanopackaging]

The current status of synthesized semiconductor and metallic nanowires is still far from practical applications. However, in many cases, they serve as good technological precursors because their size and various physical properties are beyond what are obtainable from their lithographically patterned counterparts. Recently, aluminum nanowires (AlNWs) without grain boundaries and surface roughness were synthesized using a stress-induced growth technique. They exhibited ideal resistivity, high breakdown current density, and superb transmission at microwave frequencies, all of which provide clues for future very-large-scale integrated circuit (VLSIC) interconnects.

Nisi Nanowires with Interconnect-Embedded Devices

An material showing small-enough resistivity is NiSi nanowires. They are first fabricated by synthesizing silicon nanowires via vapor-liquid-solid (VLS) growth [[3], Figure 1(a)] and then silicidating from the Ni contacts at both ends. The resistivity of was observed [4]–[6] in the fully silicided nanowires, which is well below the expected minimum resistivity required by ITRS. Furthermore, the position of interface between the silicon and silicide can be controlled by the silicidation time [6] so that we can fabricate a field-effect transistor (FET) with extended NiSi interconnects [Figure 1(b)]. This technique allows the fabrication of interconnect-embedded devices with much simpler interconnection schemes [Figure 1(c)]. Figure 1(d) shows the characteristic of a silicon nanowire FET measured at various temperatures.