n-Type Doping of Vapor–Liquid–Solid Grown GaAs Nanowires

In this letter, n-type doping of GaAs nanowires grown by metal–organic vapor phase epitaxy in the vapor–liquid–solid growth mode on (111)B GaAs substrates is reported. A low growth temperature of 400°C is adjusted in order to exclude shell growth. The impact of doping precursors on the morphology of GaAs nanowires was investigated. Tetraethyl tin as doping precursor enables heavily n-type doped GaAs nanowires in a relatively small process window while no doping effect could be found for ditertiarybutylsilane. Electrical measurements carried out on single nanowires reveal an axially non-uniform doping profile. Within a number of wires from the same run, the donor concentrations ND of GaAs nanowires are found to vary from 7 × 1017 cm-3 to 2 × 1018 cm-3. The n-type conductivity is proven by the transfer characteristics of fabricated nanowire metal–insulator-semiconductor field-effect transistor devices

<it>n</it>-Type Doping of Vapor&#8211;Liquid&#8211;Solid Grown GaAs Nanowires

<p>Abstract</p> <p>In this letter, <it>n</it>-type doping of GaAs nanowires grown by metal&#8211;organic vapor phase epitaxy in the vapor&#8211;liquid&#8211;solid growth mode on (111)B GaAs substrates is reported. A low growth temperature of 400&#176;C is adjusted in order to exclude shell growth. The impact of doping precursors on the morphology of GaAs nanowires was investigated. Tetraethyl tin as doping precursor enables heavily <it>n</it>-type doped GaAs nanowires in a relatively small process window while no doping effect could be found for ditertiarybutylsilane. Electrical measurements carried out on single nanowires reveal an axially non-uniform doping profile. Within a number of wires from the same run, the donor concentrations <it>N</it>_D of GaAs nanowires are found to vary from 7 &#215; 10¹⁷ cm^-3 to 2 &#215; 10¹⁸ cm^-3. The <it>n</it>-type conductivity is proven by the transfer characteristics of fabricated nanowire metal&#8211;insulator-semiconductor field-effect transistor devices.</p