An In-Situ Prepared Nano-Manipulator Tip for Electrical Characterization of Free Standing Graphene Like Sheets Inside a Focused Ion Beam/Scanning Electron Microscope

作者：Blom T; Jafri S H M; Widenkvist E; Jansson U; Grennberg H; Quinlan R A; Holloway B C; Leifer K^*

来源：Journal of Nanoelectronics and Optoelectronics, 2011, 6(2): 162-168.

DOI：10.1166/jno.2011.1154

• Graphene
• Carbon Nanosheets
• Nanoobjects
• Electrical Characterization
• Focused Ion Beam
• FIB
• Scanning Electron Microscope
• SEM

Nano-objects are often similar but not the identical and can have a considerable variation size and structure. These variations make nanomaterials difficult to characterise electrically and often require characterisation of a large number of objects. Thus, a fast and reproducible nano-probe technique is a necessity to acquire a large number of electrical measurements. Nano-manipulators have become a common tool in many scanning electron microscopes (SEMs) and focused ion beam (FIB) microscopes. The manipulators can be rapidly and reproducibly moved from one nano-object to another. In this work we present a procedure to obtain reproducible electrical measurements of nano- to micron-sized objects by using a tungsten tip with well defined surface properties. The tip is a part of a manipulator and is sharpened in-situ by using the gallium ion beam inside a FIB/SEM. The contact resistance between the tungsten tip and a gold surface is measured to 70 k Omega before the sharpening procedure and 10 Omega after sharpening. In this study the characterisation technique is applied to measure the resistance of as-grown, water treated and HCI treated carbon nanosheet (CNS) samples. The CNSs on each sample vary in size and morphology. Using this nano-contacting setup, we could obtain measurements of more than 400 different CNSs. The measured resistances were statistically analyzed in histograms which allowed us to observe a clear decrease of the resistance between the as-grown and a CNS sample exposed to HCI for 3 hours. However, longer exposure-times did not further modify the resistance of the CNSs.

• 出版日期2011-6