Synthesis and in situ characterization of low-resistivity TaNx films by remote plasma atomic layer deposition

Abstract

Remote plasma atomic layer deposition (ALD) of TaNx films from Ta[N(CH3)2]5 and H2, H2-N2, and NH3 plasmas is reported. From film analysis by in situ spectroscopic ellipsometry and various ex situ techniques, data on growth rate, atomic composition, mass density, TaNx microstructure, and resistivity are presented for films deposited at substrate temperatures between 150 and 250°C. It is established that cubic TaNx films with a high mass density (12.1gcm−3) and low electrical resistivity (380μΩcm) can be deposited using a H2 plasma with the density and resistivity of the films improving with plasma exposure time. H2-N2 and NH3 plasmas resulted in N-rich Ta3N5 films with a high resistivity. It is demonstrated that the different TaNx phases can be distinguished in situ by spectroscopic ellipsometry on the basis of their dielectric function with the magnitude of the Drude absorption yielding information on the resistivity of the films. In addition, the saturation of the ALD surface reactions can be determined by monitoring the plasma emission, as revealed by optical emission spectroscopy.

Characterization of HfO N thin film formation by in-situ plasma enhanced atomic layer deposition using NH3 and N2 plasmas

“…As the plasma density is increased, more numbers of the radicals and ions chemically react on the film surface resulting in the increase of growth rate. In general, for the film deposition using N 2 plasma, H 2 plasma is also utilized for the deposition process to promote the film growth characteristics since H radical can promote Hf N bonding by the reduction of precursor ligand easily [27]. In our work, since the N 2 plasma is solely utilized for the comparison of the case for using NH 3 plasma, the growth rate using N 2 plasma is lower than that of using NH 3 plasma.…”

Sub-nanometer dimensions control of core/shell nanoparticles prepared by atomic layer deposition

“…The NPs have been prepared in an open-load ALD reactor equipped with a remote plasma source, described in detail elsewhere [44]. The precursors, methylcyclopentadienyl-(trimethyl)platinum (MeCpPtMe 3 , 98%) and palladium hexafluoroacetylacetonate (Pd(hfac) 2 , 99%), were obtained from Sigma-Aldrich and were used as received.…”

Nitrogen-rich transition metal nitrides

“…Often these films are amorphous and a significant part of the research effort has been to avoid the formation of the higher Ta oxidation state to produce metallic compositions for use as barrier layers and conductive gate materials [50,51]. A novel nitrogen-rich tantalum nitride phase produced by plasma enhanced CVD from TaCl 5 and nitrogen is Ta 2 N 3 , which crystallises with a cubic Mn 2 O 3 -type ordered defect fluorite lattice [52].…”