Microstructural comparisons of ultrathin Cu films deposited by ion-beam and dc-magnetron sputtering

Abstract

We report and contrast both the electrical resistance and the microstructure of copper thin films deposited in an oxygen containing atmosphere by ion-beam and dcmagnetron sputtering. For films with thicknesses 5 nm or less, the resistivity of the Cu films is minimized at oxygen concentrations ranging from 0.2% to 1% for dc-magnetron sputtering and 6% to 10% for ion beam sputtering. Films sputtered under both conditions show a similar decrease of interface roughness with increasing oxygen concentration, although the magnetron deposited films are smoother. The dc-magnetron produced films have higher resistivity, have smaller Cu grains, and contain a higher concentration of cuprous oxide particles. We discuss the mechanisms leading to the grain refinement and the consequent reduced resistivity in both types of films.

Nitrogen-Mediated Growth of Silver Nanocrystals to Form UltraThin, High-Purity Silver-Film Electrodes with Broad band Transparency for Solar Cells

“…The use of surface-active adsorbates has proven successful for the synthesis of metal NCs with well-tailored orientations and shapes in chemical solution processes. , Inspired by this, the addition of gas adsorbates, which are mostly reactive with the host metals, has been extensively practiced in the vapor deposition of metals as a means of tuning the structural and morphological characteristics of metal NCs in a manner that promotes the two-dimensional (2D) growth mode of the metals. − From a thermodynamic viewpoint, the main role of the gas additives is to reduce the surface free energy of the metal NCs and thus alleviate the mismatch in the surface free energies of the objective metal and the oxide substrates. This arises as a result of the covalent bonds of the metal with gas additives, predominantly through oxidation − and sulfidation , for Ag, leading to a substantial reduction in the surface free energy of the metals. , The efficacy of gas additives during the very early stages of metal growth was confirmed by experimental studies of the gas additive-induced mitigation of the 3D growth mode of metals. ,− Despite such notable advantages, the use of gas additives as wetting agents for metal growth is still subject to serious restrictions resulting from the non-negligible deterioration in the chemical and structural integrity of the host metals. This is caused by the formation of chemical compounds via the chemisorption of gas residues into the host metals, which may prevent the host metals from exhibiting their optimum levels of optoelectrical performance.…”

Spectroscopic and Morphological Investigation of Copper Oxide Thin Films Prepared by Magnetron Sputtering at Various Oxygen Ratios

“…11 Many investigations have used magnetron sputtering for preparation of Cu films 12,13 as well. In this research, reactive radio frequency (RF) magnetron sputtering was used to prepare Cu and Cu oxide films with various oxygen ratios in the sputtering gas.…”

Transparent aluminium nanowire electrodes with optical and electrical anisotropic response fabricated by defocused ion beam sputtering

“…A c c e p t e d M a n u s c r i p t In analogy with the approach followed for Au NW electrodes [24], we have tried to apply the Namba-Prater (NP) model [43] in order to interpret the resistivity trend as a function of the residual film thickness. The model describes the resistivity of a metal film as the sum of scattering contributions from the bulk and from the surface in the classical size effect regime, i.e.…”