Optical Properties of Silica Films Prepared on Sapphire

As a coating material with excellent optical and mechanical properties, silica films can be used as anti-reflective and protective layers on the windows and domes of sapphire. In this paper, the designed films of SiO2 have been prepared on sapphire wafers and hemisphere dome of sapphire by radio frequency magnetron reactive sputtering. Compositions and structure of SiO2 films were analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The refractive index of deposited films was measured and effects of the coatings on optical properties of sapphire have been studied. The results express that the refractive index of the films can be varied between 3.4 and 1.4 by changing the gas flow ratio. The deposited films can increase the transmission of sapphire in mid-wave IR greatly. The average transmittance of sapphire wafers coated with SiO2 films on both sides can be increased to 96.43 % in 3～5 µm.

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Effect of film chemistry on refractive index of plasma-enhanced chemical vapor deposited silicon oxynitride films: A correlative study

Journal of Materials Research ◽

10.1557/jmr.2008.0176 ◽

2008 ◽

Vol 23 (5) ◽

pp. 1433-1442 ◽

Cited By ~ 2

Author(s):

S. Naskar ◽

S.D. Wolter ◽

C.A. Bower ◽

B.R. Stoner ◽

J.T. Glass

Keyword(s):

Refractive Index ◽

Hydrogen Concentration ◽

Photoelectron Spectroscopy ◽

Gas Flow ◽

Chemical Vapor ◽

Silicon Oxynitride ◽

Rf Plasma ◽

Flow Ratio ◽

Plasma Chemical Vapor Deposition ◽

Gas Flow Ratio

Thick SiOxNy films were deposited by radiofrequency (rf) plasma chemical vapor deposition using silane (SiH4) and nitrous oxide (N2O) source gases. The influence of deposition conditions of gas flow ratio, rf plasma mixed-frequency ratio (100 kHz, 13.56 MHz), and rf power on the refractive index were examined. It was observed that the refractive index of the SiOxNy films increased with N and Si concentration as measured via x-ray photoelectron spectroscopy. Interestingly, a variation of refractive index with N2O:SiH4 flow ratio for the two drive frequencies was observed, suggesting that oxynitride bonding plays an important role in determining the optical properties. The two drive frequencies also led to differences in hydrogen concentration that were found to be correlated with refractive index. Hydrogen concentration has been linked to significant optical absorption losses above index values of ∼1.6, which we identified as a saturation level in our films.

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Defect Passivation and Carrier Reduction Mechanisms in Hydrogen-Doped In-Ga-Zn-O (IGZO:H) Films upon Low-Temperature Annealing for Flexible Device Applications

Materials ◽

10.3390/ma15010334 ◽

2022 ◽

Vol 15 (1) ◽

pp. 334

Author(s):

Rostislav Velichko ◽

Yusaku Magari ◽

Mamoru Furuta

Keyword(s):

Low Temperature ◽

Photoelectron Spectroscopy ◽

Oxygen Diffusion ◽

Gas Flow ◽

Hydrogen Gas ◽

Oxide Semiconductor ◽

Activation Temperature ◽

X Ray ◽

Gas Flow Ratio ◽

Temperature Activation

Low-temperature activation of oxide semiconductor materials such as In-Ga-Zn-O (IGZO) is a key approach for their utilization in flexible devices. We previously reported that the activation temperature can be reduced to 150 °C by hydrogen-doped IGZO (IGZO:H), demonstrating a strong potential of this approach. In this paper, we investigated the mechanism for reducing the activation temperature of the IGZO:H films. In situ Hall measurements revealed that oxygen diffusion from annealing ambient into the conventional Ar/O2-sputtered IGZO film was observed at >240 °C. Moreover, the temperature at which the oxygen diffusion starts into the film significantly decreased to 100 °C for the IGZO:H film deposited at hydrogen gas flow ratio (R[H2]) of 8%. Hard X-ray photoelectron spectroscopy indicated that the near Fermi level (EF) defects in the IGZO:H film after the 150 °C annealing decreased in comparison to that in the conventional IGZO film after 300 °C annealing. The oxygen diffusion into the film during annealing plays an important role for reducing oxygen vacancies and subgap states especially for near EF. X-ray reflectometry analysis revealed that the film density of the IGZO:H decreased with an increase in R[H2] which would be the possible cause for facilitating the O diffusion at low temperature.

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Synthesis and Characterization of Siof Thin Films Deposited by Ecrcvd for Ulsi Multilevel Interconnections

MRS Proceedings ◽

10.1557/proc-427-427 ◽

1996 ◽

Vol 427 ◽

Cited By ~ 1

Author(s):

Seoghyeong Lee ◽

Jong-Wan Park

Keyword(s):

Dielectric Constant ◽

Refractive Index ◽

Photoelectron Spectroscopy ◽

Gas Flow ◽

Fluorine Content ◽

Fluorine Concentration ◽

Flow Ratio ◽

Ecr Plasma ◽

Gas Flow Ratio

AbstractLow dielectric constant fluorine doped silicon oxide films were deposited by using ECR plasma CVD with SiF4 and O2 as source gases diluted in Ar gas. Characterization of films was carried out in terms of various gas flow ratios (SiF4/O2 = 0.2 ∼ 1.6). The microwave power and substrate temperature during deposition were fixed at 700W and 300°C, respectively. The chemical bonding structure of the films was evaluated by Fourier transform infrared spectroscopy (FTIR), fluorine concentration by X-ray photoelectron spectroscopy (XPS) and refractive index by ellipsometry. Dielectric constant was determined from C-V measurements at 1MHz. FTIR spectra shows that as the fluorine concentration increases, peak intensities of Si-F bonding and shoulder peak at around 1160cm−1 of Si-O stretching mode increased. Moreover, with increasing the fluorine concentration in the SiOF film, the peak position of Si-O stretching mode shifts to the higher wavenumber side. The Si-F2 bond peak is observed to rise when the SiF4/O2 gas flow ratio is larger than 1.0. Refractive index and film density decreased with increasing the SiF4/O2 gas flow ratio. The SiOF film deposited at SiF4/O2 gas flow ratio of 1.0 exhibited fluorine content of 11.8 at.% and dielectric constant of 3.14.

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Effect of Nitrogen-to-Total Gas Flow Ratio on the Nanocomposite TiAlBN Coating

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.761.431 ◽

2015 ◽

Vol 761 ◽

pp. 431-435

Author(s):

Zulkifli Rosli ◽

Wai Loon Kwan ◽

Mohd Warikh Ab Rashid ◽

Jariah Mohd Juoi ◽

Nayan Nafarizal

Keyword(s):

Grain Size ◽

Photoelectron Spectroscopy ◽

Gas Flow ◽

Boron Concentration ◽

Rf Magnetron Sputtering ◽

Crystallographic Structure ◽

Chemical Compositions ◽

Flow Ratio ◽

X Ray ◽

Gas Flow Ratio

A nanocomposite TiAlBN (n-TiAlBN) coating has been successfully deposited via RF magnetron sputtering by varying the nitrogen-to-total gas flow ratio (RN) at a substrate temperature of 300 °C. The coating was deposited on AISI 316 substrates using a single Ti-Al-BN hot-pressed target. The crystal phases, grain size and chemical composition of the coatings were measured using the glancing angle X-ray diffraction analysis (GAXRD) and X-ray photoelectron spectroscopy (XPS). The grains size of the n-TiAlBN coating was found to be within the range of 3.5 to 5.7 nm calculated using Scherrer’s formula. The n-TiAlBN coating reached a nitride saturated state at a higher RN (e.g >15%) with the amount of boron concentration to be around 9 at. %. Further, reducing the RN (e.g. 5%) has increased the boron concentration to 16.17 at. %. This paper shows that by carefully control the nitrogen-to-total gas flow ratio (RN) in the n-TiAlBN coating, it indeed gives a significant effect on its crystallographic structure, grain size, and chemical compositions.

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X-ray photoelectron spectroscopy insights on interfaces between SiO2 films and GaN substrates: differences due to depositional technique

Japanese Journal of Applied Physics ◽

10.35848/1347-4065/abab45 ◽

2020 ◽

Vol 59 (9) ◽

pp. 090902

Author(s):

Noritake Isomura ◽

Narumasa Soejima ◽

Tomohiko Mori ◽

Satoshi Ikeda ◽

Atsushi Watanabe ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Sio2 Films ◽

X Ray

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Phytosynthetic Fabrication of Lanthanum Ion-Doped Nickel Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Anti-Microbial Properties

Crystals ◽

10.3390/cryst11020124 ◽

2021 ◽

Vol 11 (2) ◽

pp. 124

Author(s):

Srihasam Saiganesh ◽

Thyagarajan Krishnan ◽

Golla Narasimha ◽

Hesham S. Almoallim ◽

Sulaiman Ali Alhari ◽

...

Keyword(s):

Electron Microscopy ◽

Optical Properties ◽

Rare Earth ◽

Nickel Oxide ◽

Photoelectron Spectroscopy ◽

Metal Oxide Nanoparticles ◽

Oxide Nanoparticles ◽

Nio Nanoparticles ◽

X Ray ◽

Sesbania Grandiflora

Over the past few years, the photogenic fabrication of metal oxide nanoparticles has attracted considerable attention, owing to the simple, eco-friendly, and non-toxic procedure. Herein, we fabricated NiO nanoparticles and altered their optical properties by doping with a rare earth element (lanthanum) using Sesbania grandiflora broth for antibacterial applications. The doping of lanthanum with NiO was systematically studied. The optical properties of the prepared nanomaterials were investigated through UV-Vis diffuse reflectance spectra (UV-DRS) analysis, and their structures were studied using X-ray diffraction analysis. The morphological features of the prepared nanomaterials were examined by scanning electron microscopy and transmission electron microscopy, their elemental structure was analyzed by energy-dispersive X-ray spectral analysis, and their oxidation states were analyzed by X-ray photoelectron spectroscopy. Furthermore, the antibacterial action of NiO and La-doped NiO nanoparticles was studied by the zone of inhibition method for Gram-negative and Gram-positive bacterial strains such as Escherichia coli and Bacillus sublitis. It was evident from the obtained results that the optimized compound NiOLa-04 performed better than the other prepared compounds. To the best of our knowledge, this is the first report on the phytosynthetic fabrication of rare-earth ion Lanthanum (La3+)-doped Nickel Oxide (NiO) nanoparticles and their anti-microbial studies.

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Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽

10.3390/coatings11080937 ◽

2021 ◽

Vol 11 (8) ◽

pp. 937

Author(s):

Yingying Hu ◽

Md Rasadujjaman ◽

Yanrong Wang ◽

Jing Zhang ◽

Jiang Yan ◽

...

Keyword(s):

Crystal Structure ◽

Optical Properties ◽

Photoelectron Spectroscopy ◽

Crystal Size ◽

Silicon Substrates ◽

X Ray Diffraction ◽

Dc Magnetron Sputtering ◽

Flow Rates ◽

X Ray ◽

N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

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Surface Stoichiometry and Depth Profile of Tix-CuyNz Thin Films Deposited by Magnetron Sputtering

Materials ◽

10.3390/ma14123191 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3191

Author(s):

Arun Kumar Mukhopadhyay ◽

Avishek Roy ◽

Gourab Bhattacharjee ◽

Sadhan Chandra Das ◽

Abhijit Majumdar ◽

...

Keyword(s):

Magnetron Sputtering ◽

Photoelectron Spectroscopy ◽

Film Surface ◽

Grazing Incidence ◽

X Ray Diffraction ◽

X Ray ◽

Relative Composition ◽

Transmission Electron ◽

Deposited Film ◽

Deposited Films

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase.

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Effect of Nitrogen Doping on the Structure and Optical Properties of N-Type Hydrogenated Amorphous Silicon Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.6980 ◽

2011 ◽

Vol 383-390 ◽

pp. 6980-6985

Author(s):

Mao Yang Wu ◽

Wei Li ◽

Jun Wei Fu ◽

Yi Jiao Qiu ◽

Ya Dong Jiang

Keyword(s):

Thin Films ◽

Optical Properties ◽

Amorphous Silicon ◽

Photoelectron Spectroscopy ◽

Gas Flow ◽

Hydrogenated Amorphous Silicon ◽

Chemical Vapor ◽

Silicon Thin Films ◽

Frequency Plasma ◽

Hydrogenated Amorphous

Hydrogenated amorphous silicon (a-Si:H) thin films doped with both Phosphor and Nitrogen are deposited by ratio frequency plasma enhanced chemical vapor deposition (PECVD). The effect of gas flow rate of ammonia (FrNH3) on the composition, microstructure and optical properties of the films has been investigated by X-ray photoelectron spectroscopy, Raman spectroscopy and ellipsometric spectra, respectively. The results show that with the increase of FrNH3, Si-N bonds appear while the short-range order deteriorate in the films. Besides, the optical properties of N-doped n-type a-Si:H thin films can be easily controlled in a PECVD system.

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Deposition of Cobalt Doped Zinc Oxide Thin Film Nano-Composites Via Pulsed Electron Beam Ablation

MRS Advances ◽

10.1557/adv.2016.44 ◽

2016 ◽

Vol 1 (6) ◽

pp. 433-439 ◽

Cited By ~ 6

Author(s):

Asghar Ali ◽

Patrick Morrow ◽

Redhouane Henda ◽

Ragnar Fagerberg

Keyword(s):

Zinc Oxide ◽

Electron Beam ◽

Binding Energy ◽

Photoelectron Spectroscopy ◽

Xrd Analysis ◽

Sem Analysis ◽

Oxide Thin Film ◽

X Ray ◽

Pulsed Electron Beam ◽

Deposited Films

AbstractThis study reports on the preparation of cobalt doped zinc oxide (Co:ZnO) films via pulsed electron beam ablation (PEBA) from a single target containing 20 w% Co on sapphire (0001) and silicon (100) substrates. The films have been deposited at various temperatures (350оC, 400оC, 450оC) and pulse frequencies (2 Hz, 4 Hz), under a background argon (Ar) pressure of about 3 mtorr, and an accelerating voltage of 14 kV. The surface morphology has been examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). According to SEM analysis, the films consist of nano-globules whose size is in the range of 80-178 nm. Energy dispersive x-ray spectroscopy (EDX) reveals that deposition is congruent and the prepared films contain ∼20±5 w% cobalt. It has been found that the nano-globules in the deposited films are cobalt-rich zones containing ∼70 w% Co. From x-ray photoelectron spectroscopy (XPS) analysis, Co 2p3/2 peaks indicate that the deposited films contain CoO (binding energy = 780.5 eV) as well as metallic Co (binding energy = 778.1-778.5 eV). X-ray diffraction (XRD) analysis supports the presence of metallic Co hcp phase (2ϴ = 44.47° and 47.43°) in the films.

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