Laboratory for Electronics/Metrology/Reliability, EMPA, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
Nanotechnology. 2013 Oct 4;24(39):395301. doi: 10.1088/0957-4484/24/39/395301. Epub 2013 Sep 6.
We demonstrate a reliable fabrication method to produce plasmonic dipole nanoantennas with gap values in the range of 3.5-20 nm. The method combines electron beam lithography to create gold nanorods and helium focused ion beam milling to cut the gaps. Results show a reproducibility within 1 nm. Scattering spectra of antennas show a red shift of resonance wavelengths and an increase of the intensity of resonance peaks with a decrease of the gap size, which is in agreement with finite element simulations. The measured refractive index sensitivity was about 250 nm per refractive index unit for antennas with gap values below 5 nm.
我们展示了一种可靠的制造方法，可以生产出间隙值在 3.5-20nm 范围内的等离子体偶极纳米天线。该方法结合电子束光刻来制造金纳米棒，并采用氦离子束铣削来切割间隙。结果显示，间隙值的重复性在 1nm 以内。天线的散射光谱显示，随着间隙尺寸的减小，共振波长发生红移，共振峰强度增加，这与有限元模拟结果一致。对于间隙值小于 5nm 的天线，测量的折射率灵敏度约为每个折射率单位 250nm。
