Properties of radio frequency–sputtered alumina films on flat and grooved substrates

Abstract

Influence of the target-substrate distance on the properties of indium tin oxide films prepared by radio frequency reactive magnetron sputtering Mechanical and chemical properties of rf-diode sputtered alumina films have been measured as a function of deposition conditions including substrate bias, bias phase, and sputter power. Similar films were deposited over grooved substrates, and the effect of the grooves on film microstructure and intrinsic stress was examined. Films deposited over nonplanar substrates show distinct regions in the vicinity of substrate steps where the material has a different microstructure, composition, stress, and chemical etch rate compared with material far from the steps. The elastic modulus and hardness of the material near the steps were measured by nanoindentation.

Superhydrophobic Coatings Based on Pseudoboehmite Nanoflakelets for Sustainable Photovoltaic Energy Production

“…The observed hardness value of the a -Al 2 O 3 film was found to be slightly higher than the reported value (8.1 ± 1.3 GPa at a load of 0.5 mN) . Also, the measured average elastic modulus of the amorphous thin film lies within the reported range (70–190 GPa). − Nanoindentation on SH hierarchical nanoflakelets exhibited a reduction in the average hardness (2.08 ± 1.61 GPa) and elastic modulus (84.1 ± 40.7 GPa) compared to smooth a -Al 2 O 3 thin film (≈134 GPa). The AlOOH nanostructure was affected by various microscopic factors, notably the porosity, inelastic layer slippage, decrease of hydrogen bonds, voids in the octahedral boehmite crystal structure, and weak bonding between the layered structures of boehmite.…”

Plasma deposition of constrained layer damping coatings

“…6 that the standard MSE significantly overpredicts the damping while the modified version gives a slight underprediction. Note that loss factor curves for other modes were similar in shape to those presented: maximum levels were identical but [11,30]. In the more general case, however, where FE models are used, the modal stiffness (i.e.…”

“…. For a simple structure such as beams, closed-form expressions for these parameters have been obtained based on the classical Ross, Kerwin and Ungar (RKU) analysis [11,30]. In the more general case, however, where FE models are used, the modal stiffness (i.e.…”

“…For example, alumina films can be obtained either via standard PVD, from an alumina target in an argon plasma, or by reactive PVD, from an aluminium target in an argon/oxygen plasma. Radio frequency (RF) plasma sputter deposition has been used to grow alumina coatings up to 200 mm in thickness, with values of Young's modulus ranging from 140 to 180 GPa [11]. While this is significantly less than the modulus for bulk alumina, the modulus-density ratio still exceeds that for metals.…”

Corrosion studies of DC reactive magnetron sputtered alumina coating on 304 SS

“…Amorphous alumina (aluminum oxide) thin films have many applications and have attracted much attention during the past 20 years [1]. Aluminum oxide thin films are widely used in many mechanical, optical and microelectronic applications [2].…”