Limits of 3-D nanostructures fabricated by focused electron beam (FEB) induced deposition

The focused electron beam of an electron microscope (SEM or TEM) decomposes tailored precursor molecules on substrates into functional deposits. Extremely high aspect ratios of more than 10 can easily be obtained. During the last years several materials could be deposited, most of them composed of metal nanoparticles embedded in amorphous matrices. The deposition process depends on the precursor supply, its surface adsorption behavior, and the beam induced chemical decomposition path of the molecule on one hand, and on the other hand on the electron beam properties like beam current, electron energy, and beam distribution. The limits in minimal size, growth rate, and chemical composition arise from all mentioned parameters, which are interdependent.