Qian Wen, Sun Shuo, Song Jingfeng, Nguyen Charles, Ducharme Stephen, Turner Joseph A
Department of Mechanical & Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska NE, United States of America.
Nanotechnology. 2018 Aug 17;29(33):335702. doi: 10.1088/1361-6528/aac73c. Epub 2018 May 23.
We report on the fabrication of metallic, ultra-sharp atomic force microscope tips for localized nanoscale infrared (IR) spectrum measurements by using focused electron-beam-induced deposition of platinum or tungsten. The tip length can be controlled by changing the duration time of the electron beam. Probes of 12.0 ± 5.0 nm radius-of-curvature can be routinely produced with high repeatability and near-100% yield. The near-field-enhancement appears stronger at the extremity of the metallic tip, compared with commercial pristine silicon-nitride probe tip. Finally, the performance of the modified metallic tips is demonstrated by imaging PVDF and PMMA thin films, which shows that spatial resolution is greatly enhanced. In addition, the signal intensity of the localized nanoscale IR spectrum is increased offering greater sensitivity for chemical IR imaging.
我们报告了通过聚焦电子束诱导沉积铂或钨来制造用于局部纳米级红外（IR）光谱测量的金属超尖锐原子力显微镜探针。可以通过改变电子束的持续时间来控制探针长度。曲率半径为12.0±5.0 nm的探针可以常规生产，具有高重复性和近100%的产率。与商业原始氮化硅探针尖端相比，金属尖端末端的近场增强似乎更强。最后，通过对聚偏氟乙烯（PVDF）和聚甲基丙烯酸甲酯（PMMA）薄膜成像展示了改性金属尖端的性能，这表明空间分辨率大大提高。此外，局部纳米级红外光谱的信号强度增加，为化学红外成像提供了更高的灵敏度。
