Comparative Study of Pore Characterizations of Anodized Al–0.5 wt.% Cu Thin Films in Oxalic and Phosphoric Acids

NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950140
Author(s):  
Alaa M. Abd-Elnaiem ◽  
S. Moustafa ◽  
T. B. Asafa
Keyword(s):  
Thin Films ◽  
Oxalic Acid ◽  
Phosphoric Acid ◽  
Etching Rate ◽  
Silicon Wafers ◽  
Average Particle ◽  
Text Type ◽  
Type Silicon ◽  
Steady State Current ◽  
Phosphoric Acids

Porous anodic alumina (PAA) thin films, having interconnected pores, were fabricated from Cu-doped aluminum films deposited on [Formula: see text]-type silicon wafers by anodization. The anodization was done at four different anodizing voltages (60[Formula: see text]V, 70[Formula: see text]V, 80[Formula: see text]V and 90[Formula: see text]V) in phosphoric acid and two voltages (60[Formula: see text]V and 70[Formula: see text]V) in oxalic acid. The aluminum and PAA samples were characterized by SEM and XRD while the pore arrangement, pore density, pore diameter, pore circularity and pore regularity were also analyzed. XRD spectra confirmed the aluminum to be crystalline with the dominant plane being (220), the Cu-rich phase have an average particle size of [Formula: see text][Formula: see text]nm uniformly distributed within the Al matrix of 0.4-[Formula: see text]m grain size. The steady-state current density through the anodization increased by 117% and 49% for oxalic and phosphoric acids, respectively, for 10[Formula: see text]V increase (from 60 to 70 V) in anodization voltage. Similarly, the etching rate increased by 100% for oxalic acid and by 40% for phosphoric acid which are responsible for 47% and 29% decreases in anodization duration, respectively. The highest value of circularity obtained for anodized Al–0.5[Formula: see text]wt.% Cu formed in oxalic acid at 60[Formula: see text]V was 0.86, and it was 0.80 for the phosphoric acid at 90[Formula: see text]V. Anodization of Al–0.5[Formula: see text]wt.% Cu films allows the formation of circular pores directly on [Formula: see text]-type silicon wafers which is of importance for future nanofabrication of advanced electronics. The results of anodized Al–0.5[Formula: see text]wt.% Cu thin film were compared with other anodized systems such as anodized pure Al and Al doped with Si.

Uniform Tetragonal WSi2 Layers Formed by RTA

1986 ◽  
Vol 74 ◽  
Author(s):  
M. Siegal ◽  
J. J. Santiago ◽  
J. Van Der Spiegel ◽  
W. R. Graham ◽  
M. Setton
Keyword(s):  
Thin Films ◽  
High Vacuum ◽  
Silicon Wafers ◽  
Tungsten Silicide ◽  
Type Silicon ◽  
Oxide Barrier ◽  
P Type

AbstractThin films of tungsten silicide with resistivities of 30 – 35 μΩ-cm have been formed by sputter depositing 71 nm of W metal onto (100) oriented, 5 Ω-cm, p-type silicon wafers that were etched in BOE 500 solution. The samples were fast radiatively processed in an RTA system under high vacuum for time anneals ranging from 15 – 50 seconds at a temperature of ∼ 1100°C. The inevitable oxide barrier at the interface is shown to decrease with increasing RTA time.

scholarly journals Influence of Substrate Materials on Nucleation and Properties of Iridium Thin Films Grown by ALD

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Paul Schmitt ◽  
Vivek Beladiya ◽  
Nadja Felde ◽  
Pallabi Paul ◽  
Felix Otto ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Bulk Material ◽  
Atomic Layer ◽  
Substrate Material ◽  
Fused Silica ◽  
Silicon Wafers ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Influence Of Substrate

Ultra-thin metallic films are widely applied in optics and microelectronics. However, their properties differ significantly from the bulk material and depend on the substrate material. The nucleation, film growth, and layer properties of atomic layer deposited (ALD) iridium thin films are evaluated on silicon wafers, BK7, fused silica, SiO2, TiO2, Ta2O5, Al2O3, HfO2, Ru, Cr, Mo, and graphite to understand the influence of various substrate materials. This comprehensive study was carried out using scanning electron and atomic force microscopy, X-ray reflectivity and diffraction, four-point probe resistivity and contact angle measurements, tape tests, and Auger electron spectroscopy. Within few ALD cycles, iridium islands occur on all substrates. Nevertheless, their size, shape, and distribution depend on the substrate. Ultra-thin (almost) closed Ir layers grow on a Ta2O5 seed layer after 100 cycles corresponding to about 5 nm film thickness. In contrast, the growth on Al2O3 and HfO2 is strongly inhibited. The iridium growth on silicon wafers is overall linear. On BK7, fused silica, SiO2, TiO2, Ta2O5, Ru, Cr, and graphite, three different growth regimes are distinguishable. The surface free energy of the substrates correlates with their iridium nucleation delay. Our work, therefore, demonstrates that substrates can significantly tailor the properties of ultra-thin films.

Nanosized Hydroxyapatite Powder Synthesized from Eggshell and Phosphoric Acid

2007 ◽  
Vol 7 (11) ◽  
pp. 4061-4064 ◽  
Author(s):  
Sang-Jin Lee ◽  
Young-Soo Yoon ◽  
Myung-Hyun Lee ◽  
Nam-Sik Oh
Keyword(s):  
Phosphoric Acid ◽  
Heating Temperature ◽  
Average Particle Size ◽  
Stoichiometric Composition ◽  
Synthesis Process ◽  
Average Particle ◽  
Mixing Ratio ◽  
Powder Synthesis ◽  
Chemical Route ◽  
Milling Method

The present research describes synthesis of highly sinterable, nano-sized hydroxyapatite (HAp) powders using a wet chemical route with recycled eggshell and phosphoric acid as calcium and phosphorous sources. The raw eggshell was easily turned to CaO by the calcining process, and phosphoric acid was mixed with the calcined eggshell by the wet, ball-milling method. The crystalline development and microstructures of the synthesized powders and sintered samples were examined by X-ray diffractometry and scanning electron microscopy, respectively. The observed phases on the powder synthesis process were dependent on the mixing ratio (wt%) of the calcined eggshell to phosphoric acid and the heating temperature. The ball-milled, nano-sized HAp powder, which has an average particle size of 70 nm, was fully densified at 1300 °C for 1h. The Ca/P ratio for stoichiometric composition of HAp was controlled by adjustment of the mixing ratio.

scholarly journals Study of the regularity of the process of decomposition of apatite with sulfuricacid at the boilingpoint of the solution

2019 ◽  
Vol 58 (4) ◽  
pp. 119-122
Author(s):  
Rauf F. Sabirov ◽  
◽  
Alexey F. Makhotkin ◽  
Yury N. Sakharov ◽  
Igor A. Makhotkin ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Boiling Point ◽  
Batch Reactor ◽  
Material Balance ◽  
Mercury Thermometer ◽  
Experimental Values ◽  
Kinetics Of ◽  
Liquid And Solid Phases ◽  
Phosphoric Acids

Experimental research of the kinetics of the decomposition process of Kovdorsky apatite with a size = 0.16 mm with sulfuric acid in a 1 dm3 batch reactor. Phosphoric acid with the concentration of 68.6 % wt and the sulfuric acid with the concentration of 12.3% wt in stoichiometric amount was introduces at the beginning of the process. The process was carried out at a ratio of liquid and solid phases 2.5:1 respectively at the boiling point of the mixture equal to 136 °C. The observing the progress was carried out according to the method of joint designation of sulfuric and phosphoric acids by titrimetric analysis. With methyl orange and then phenolphthalein 2 titration jumps were recorded, the first of which corresponded to the neutralization of sulfuric acid to Na2SO4 and phosphoric acid to NaH2PO4, the second to the neutralization of NaH2PO4 to Na2HPO4. The change in temperature of the reaction mixture was fixed during the process using a mercury thermometer. In the analysis of the derived experimental values of specified parameters that the boiling point decreases from 136 to 133.1 оС within 50 minutes during the process. A comparison of the reported values with the concentration values of sulfuric and phosphoric acids measured during the process shows that the change in boiling point of the reaction mixture is proportional to the change in the concentrations of sulfuric and phosphoric acids. This model is a closed system that provides thermal insulation and no loss of material balance. Thus, the kinetics of the decomposition of apatite with sulfuric acid at the boiling point can be monitored by the temperature change under specified conditions.

Electrochemically Deposited Cobalt Thin Films on p‐Type Silicon and Its Characterization

1995 ◽  
Vol 142 (11) ◽  
pp. 3889-3892 ◽  
Author(s):  
C. Wisniewski ◽  
I. Denicoló ◽  
I. A. Hümmelgen
Keyword(s):  
Thin Films ◽  
Type Silicon ◽  
Electrochemically Deposited ◽  
Cobalt Thin Films ◽  
P Type

scholarly journals Evaluation of sputtered nickel oxide, cobalt oxide and nickel–cobalt oxide on n-type silicon photoanodes for solar-driven O2(g) evolution from water

2020 ◽  
Vol 8 (28) ◽  
pp. 13955-13963 ◽  
Author(s):  
Fan Yang ◽  
Xinghao Zhou ◽  
Noah T. Plymale ◽  
Ke Sun ◽  
Nathan S. Lewis
Keyword(s):  
Thin Films ◽  
Nickel Oxide ◽  
Cobalt Oxide ◽  
Water Oxidation ◽  
Type Silicon ◽  
Nickel Cobalt ◽  
Nickel Cobalt Oxide

Thin films of nickel oxide (NiOx), cobalt oxide (CoOx) and nickel–cobalt oxide (NiCoOx) produced integrated, protected Si (111) photoanodes integrated, protected Si photoanodes that did not require deposition of a separate heterogeneous electrocatalyst for water oxidation.

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