Electrical, and field emission properties of nanocrystalline materials fabricated by electron-beam induced deposition

Three-dimensional structures of nanometer dimensions can be fabricated by electron-beam induced deposition. The technique allows accurate placement of arbitrary shaped structures onto existing substrates at a single process step. It allows tips to be produced with an ultimate radius of curvature for scanning probe techniques or field emission applications. Electron-beam induced deposition from organometallic precursors produces small metallic crystallites embedded in an amorphous, carbon-containing matrix. The electrical conductivity of these deposits is highly dependent on the deposition conditions. The conductivity of material with low metal contents is found to be of Poole-Frenkel type. Field emission tips working with low extraction voltages are obtained. A high current is accomplished due to the multiple emission centers available at the front of the tip. Beam confinement to one emission site is demonstrated for the first time for a deposited supertip.