Direct Growth and Fabrication of Tungsten Coated GaN Nanowire Probes on Cantilevers for Scanning Probe Microscopy

Gallium nitride nanowires (NWs) grown on silicon-on-insulator wafers by means of selective area epitaxy are directly integrated into scanning probe cantilever fabrication. These cantilevers with NW probe tips are coated with tungsten by atomic layer deposition to take measurements on gold embedded in silicon to test the RF response of the cantilever to changes in the material properties. The sensitivity of the cantilever RF capacitance measurement was tested on a microcapacitor reference sample with 0.7 – 7.1
$\mu {m}^{2}$
microcapacitors on 10
$nm$
SiO
₂
steps. These probes have an estimated noise-limited sensitivity of 12.5
$aF$
, demonstrating the first RF cantilever with a selectively grown NW probe tip. [2021-0240]