  Direct electron beam writing is a powerful tool for fabricating complex
nanostructures in a single step. The electron beam locally cleaves the
molecules of an adsorbed gaseous precursor to form a deposit, similar to 3D
printing but without the need for a resist or development step. Here, we employ
for the first time a silver $\beta$-diketonate precursor for focused electron
beam induced deposition (FEBID). The used compound (hfac)AgPMe$_3$ operates at
an evaporation temperature of 70 - 80{\deg}C and is compatible with
commercially available gas injection systems used in any standard scanning
electron microscope. Growth of smooth 3D geometries could be demonstrated for
tightly focused electron beams, albeit with low silver contents in the deposit
volume. The electron beam induced deposition proved sensitive to the
irradiation conditions leading to varying compositions of the deposit and
internal inhomogeneities such as the formation of a layered structure
consisting of a pure silver layer at the interface to the substrate covered by
a deposit layer with low silver content. Imaging after the deposition process
revealed morphological changes such as the growth of silver particles on the
surface. While these effects complicate the application for 3D printing, the
unique deposit structure with a thin, compact silver film beneath the deposit
body is interesting from a fundamental point of view and may offer additional
opportunities for applications.
