Berlin 2012 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 13: Poster: Interfaces and Thin Films

CPP 13.26: Poster

Tuesday, March 27, 2012, 18:15–20:45, Poster A

Fabrication of carbon nanomembranes by helium ion beam lithography — •Xianghui Zhang, Henning Vieker, André Beyer, and Armin Gölzhäuser — Fäkultät für Physik, Universität Bielefeld, Postfach 10 01 31, 33501, Germany

A scanning helium-ion microscope (HIM) can be employed as an imaging and metrology tool for nanotechnology. In addition, the helium ion beam is capable of creating nano-sized patterns and it can perform ion milling as commonly done in a focused ion beam (FIB) system. It is known that aromatic self-assembled monolayers (SAMs) can be cross-linked due to electron irradiation and form mechanically stable carbon nanomembranes (CNMs). Here we use a helium ion beam as direct writing tool to cross-link 4'-nitro-1,1'-biphenyl-4-thiol (NBPT) SAMs with arbitrary patterns. The cross-linked SAMs were transferred to either silicon substrates with an oxide layer for optical characterization or transmission electron microscopy (TEM) grids for preparing free-standing CNMs. The required dose for the complete cross-linking with helium ions is quite similar to that with electrons. To determine the feature resolution limit, we prepared dot arrays of CNMs at various doses and 5 nm feature sizes have been achieved. The proximity effect and the sample damage on the nano-scale patterns were also investigated. Furthermore, we use the ion beam to form nanopores in the CNM with an attainable feature size of 5 nm.