On direct-writing methods for electrically contacting GaAs and Ge nanowire devices

Abstract

The electronic transport and gating characteristics in GaAs and Ge nanowires (NWs) are altered significantly following either indirect or direct exposure to a focused Ga+ ion beam (FIB), such as that used to produce Pt electrical contacts to NWs. While these results challenge the assumptions made in some previously reported work relating to the electronic properties of semiconductor NWs using FIB-assisted production of contacts and/or their leads, local electron beam induced deposition is shown to be a reliable and facile route for producing robust electrical contacts to individual vapor phase-grown NWs in a manner that enables study of their actual carrier transport properties.

Self-catalyzed molecular beam epitaxy growth and their optoelectronic properties of vertical GaAs nanowires on Si(111)

“…4(b) depicts the source-drain current (I ds ) versus source-drain voltage (V ds ) curves of the single GaAs nanowire under various gate voltage (V g ) from À 10 to 10 V. The I ds versus V ds curve of the GaAs nanowire revealed a typical p-type semiconductor characteristic, in which the I ds of the FET decreases with an increasing V g . The p-type conductivity in unintentionally doped GaAs NWs may be attributed to the native acceptor defects associated with gallium vacancies (V Ga ) or gallium in antimony site (GaAs) in GaAs NWs [12,44].…”

Picosecond response times in GaAs/AlGaAs core/shell nanowire-based photodetectors

“…Gating on devices fabricated with both core/shell and bare nanowires show slightly p-type behavior, attributed to unintentional doping due to precursor contaminants during growth. 14 For detector fabrication the core/shell nanowires were dispersed from an isopropyl alcohol suspension onto prepatterned substrates. Sapphire substrates were used to reduce parasitic capacitance.…”

In situ electronic probing of semiconducting nanowires in an electron microscope

“…All experiments were performed in an FEI Helios NanoLab DualBeam (FEI, Hillsboro, OR, USA) focused ion beam (FIB) system. Only the electron beam was used, as we and others have observed that the electronic properties of the nanowires were very sensitive to even stray exposure to ions (Chen et al, 2010). For electron beam induced Pt-deposition, the organometallic precursor gas trimethyl-(methylcyclopentadienyl)-platinum(IV), (CH 3 ) 3 Pt(C p CH 3 ), was used.…”