Gold nanowires fabricated by immersion plating

The growth mechanism of oriented Au nanowires fabricated by immersion plating was investigated. Both n-type crystal Si (c-Si) and amorphous Si (a-Si) with an electron-beam (E-beam) patterned resist nanotrench were immersed into the plating bath HAuCl4/HF. For the Au nanowires fabricated on c-Si, voids, nanograins, and clusters were observed at various plating conditions, time and temperature. The voids were often found in the center of the Au nanowires due to there being fewer nucleation sites on the c-Si surface. However, Au can easily nucleate on the surface of a-Si and form continuous Au nanowires with grain sizes about 10-50 nm. The resistivities of Au nanowires with width 105 nm fabricated on a-Si are about 4.4-6.5 μΩ cm. After annealing at 200 deg. C for 30 min in N2 ambient, the resistivities are lowered to about 3.0-3.9 μΩ cm, measured in an atomic force microscope (AFM) in contact mode. The grain size of Au is in the range of ∼50-100 nm. A scanning electron microscope (SEM) examination and grazing incident x-ray diffraction (GIXRD) analysis were also carried out to study the morphology and crystalline structure of the Au nanowires