Hafnium oxide films grown on silicon substrates by electron beam-induced deposition

Electron beam-induced deposition (EBID) is an effective technique for directly fabricating materials with arbitrary shapes on substrates. EBID techniques have mostly been applied to the deposition of metals; however, only a few methods have been applied to metal oxides. As an application of metal oxides in EBID, I report on the fabrication of hafnium oxide (HfO2) films and their structural analysis using transmission electron microscopy techniques. Hafnium tetra- tert-butoxide [Hf(OC4H9)4] was supplied as a precursor from the gas injection system to deposit HfO2 films on silicon substrates. As a result of structural analysis, the grain size of the HfO2 film was less than 1 nm and residual carbon in the film remained. Although deposition conditions to reduce or remove residual carbon in the films need to be improved, the results demonstrate the applicability of one method of HfO2 fabrication and the potential of the EBID method for various metal oxide depositions.