AVS 62nd International Symposium & Exhibition
    Helium Ion Microscopy Focus Topic Thursday Sessions
       Session HI+AS+NS-ThA

Paper HI+AS+NS-ThA4
Nanopores in Silicon Nitride Membranes, Graphene and CNM: Milling and Imaging Techniques at the Helium Ion Microscope

Thursday, October 22, 2015, 3:20 pm, Room 211B

Session: Imaging and Milling with He and Ne Ion Beams
Presenter: Daniel Emmrich, Bielefeld University, Germany
Authors: D. Emmrich, Bielefeld University, Germany
E. Marschewski, Bielefeld University, Germany
A. Nadzeyka, Raith GmbH, Germany
F. Nouvertné, Raith GmbH, Germany
A. Gölzhäuser, Bielefeld University, Germany
A. Beyer, Bielefeld University, Germany
Correspondent: Click to Email
The Helium Ion Microscope (HIM) is a focussed ion beam system which can be used for both imaging and milling. In the low dose regime, the HIM operates as a microscope; high doses enable material modification and sputtering. Compared to conventional focussed ion beams (FIB), the HIM offers a very small focal spot size down to 0.35 nm and a strongly localized sputter interaction with the material. We employ the HIM for milling nanopores in free standing membranes, such as 30 nm thick Silicon Nitride, Graphene and 1 nm thick carbon nanomembranes (CNM) made from aromatic self-assembled monolayers by electron-induced cross-linking. HIM is also used for the inspection of pores. The smallest He+-milled nanopores have a diameter of about 3 nm in all investigated membranes. The He+ beam thus overcomes the resolution limit of conventional FIB tools as we show in a comparison with a high resolution Ga-FIB. Different strategies for the characterization of pores with the HIM will be discussed. In particular, we compare the feasibility of the ion generated secondary electron signal to the He+ transmission signal.