The metal halide precursors have high vapor pressure are stable, reactive and therefore widely used. Cyclic voltammetry (CVA) showed that there is no current increase for tantalum (V) oxide in a potential window of 3–4.2 V and has prospects of use as protective coatings for cathode materials of SSLIBs.īoth inorganic (TaF 5, TaCl 5), and a number of organometallic precursors (TBTEMT, Ta(NtBu)Me(dmaema) 2, (t-BuN)(Et 2N) 2CpTa, TBTMET, TBTDET, TAIMATA, PDMAT, Ta(OEt) 5) are used to obtain tantalum oxides by the ALD ( Table 1). Surface of the films contain Ta 2O 5 and some carbon contamination, but the bulk of the films does not contain carbon and any precursor residues. The chemical composition of the surface and bulk of Ta-O coatings was studied by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy. The obtained thin films have a low roughness and high uniformity. The results of the X-ray reflectometry show the Ta-O films’ density is 7.98 g/cm 3, which is close to the density of crystalline Ta 2O 5 of the rhombic structure (8.18 g/cm 3). But the heat treatment study shows crystallization at 800 ☌ with the formation of the polycrystalline Ta 2O 5 phase with a rhombic structural type (Pmm2). According to the X-ray diffraction data, the as-prepared films were amorphous. Different morphology of films deposited on silicon and stainless steel was found.

The temperature range of the ALD window was 250–300 ☌, the growth per cycle was about 0.05 nm/cycle. The thickness of the films were measured by spectroscopic ellipsometry, scanning electron microscopy and X-ray reflectometry. The influence of deposition parameters (reactor and evaporator temperature, pulse and purge times) on the growth rate were studied. Tantalum (V) ethoxide (Ta(OEt) 5) and remote oxygen plasma were used as tantalum-containing reagent and oxidizing co-reagent, respectively. This article is dedicated to the Ta-O thin-film system synthesis by the atomic layer deposition (ALD) which allows to deposit high quality films and coatings with excellent uniformity and conformality. The tantalum oxide thin films are promising materials for various applications: as coatings in optical devices, as dielectric layers for micro and nanoelectronics, and for thin-films solid-state lithium-ion batteries (SSLIBs).

Tantalum pentoxide vapor pressure