Small-scale batch fabrication of carbon nanofiber probes

The batch-growth of linear-shaped single CNFs onto commercially available Si cantilevers (3 – 9 chips / batch) using the ion-irradiation method was challenged, and the growth parameters were optimized in terms of the sample temperature (up to 70C) and the ion-irradiation time. In every growth condition tested here, the batch-fabrication of CNF probes was achieved. The length and the growth direction of CNFs were controllable well with the ion-irradiation time and the ion-incidence angle, respectively. Thus, oriented and linear-shaped single CNFs, even longer than 1 m in length, were attainable. Under the optimized growth condition, CNFs were batch-grown uniformly in length with the standard deviation of less than ~10 %. CNFs showed almost no temperature dependence in growth rate, and fine CNFs tended to grow for short irradiation duration. Since AFM images of Si grating were attained repeatedly with a good image resolution using CNF probes thus batch-fabricated, the ion-irradiation method was believed to be quite promising to prepare practical CNF probes.