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16 pages, 38316 KiB

Open AccessArticle

Influence of the Active Screen Plasma Power during Afterglow Nitrocarburizing on the Surface Modification of AISI 316L

by Jan Böcker, Alexander Puth, Anke Dalke, Jürgen Röpcke, Jean-Pierre H. van Helden and Horst Biermann

Coatings 2020, 10(11), 1112; https://doi.org/10.3390/coatings10111112 - 19 Nov 2020

Cited by 13 | Viewed by 2335

Abstract

Active screen plasma nitrocarburizing (ASPNC) increases the surface hardness and lifetime of austenitic stainless steel without deteriorating its corrosion resistance. Using an active screen made of carbon opens up new technological possibilities that have not been exploited to date. In this study, the [...] Read more.

Active screen plasma nitrocarburizing (ASPNC) increases the surface hardness and lifetime of austenitic stainless steel without deteriorating its corrosion resistance. Using an active screen made of carbon opens up new technological possibilities that have not been exploited to date. In this study, the effect of screen power variation without bias application on resulting concentrations of process gas species and surface modification of AISI 316L steel was studied. The concentrations of gas species (e.g., HCN, NH₃, CH₄, C₂H₂) were measured as functions of the active screen power and the feed gas composition at constant temperature using in situ infrared laser absorption spectroscopy. At constant precursor gas composition, the decrease in active screen power led to a decrease in both the concentrations of the detected molecules and the diffusion depths of nitrogen and carbon. Depending on the gas mixture, a threshold of the active screen power was found above which no changes in the expanded austenite layer thickness were measured. The use of a heating independent of the screen power offers an additional parameter for optimizing the ASPNC process in addition to changes in the feed gas composition and the bias power. In this way, an advanced process control can be established. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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13 pages, 2835 KiB

Open AccessArticle

Adhesive Properties of Silicone-Coated Release Liner Paper Enhanced by Atmospheric Pressure Plasma Pre- and Post-Treatment

by Zlata Kelar Tučeková, Oleksandr Galmiz, Jakub Kelar, Dušan Kováčik, Monika Stupavská, Petra Šrámková, Miroslav Zemánek, Julien Vallade and Mirko Černák

Coatings 2020, 10(11), 1102; https://doi.org/10.3390/coatings10111102 - 17 Nov 2020

Cited by 7 | Viewed by 5393

Abstract

For release-liner preparation, coating stabilization of the silicone layer on base paper often requires pre- and post-treatment. In this study, we used atmospheric pressure diffuse coplanar surface barrier discharge in roll-to-roll configuration. The results of prepared coating showed that the A4 size clay-coated [...] Read more.

For release-liner preparation, coating stabilization of the silicone layer on base paper often requires pre- and post-treatment. In this study, we used atmospheric pressure diffuse coplanar surface barrier discharge in roll-to-roll configuration. The results of prepared coating showed that the A4 size clay-coated paper sprayed with silicone oil (0.25–0.50 mL) gradually decreased the tape peeling force (180°) with prolonged and repeated air plasma post-treatment. Best results showing increased hydrophobicity and significantly enhanced release factor of the coating were obtained after the plasma treatment in a nitrogen atmosphere. The silicone coating on the clay-coated paper reduced the reference release force from 5.5 N/cm to less than 1.5 N/cm after the repeated silicone spraying and short nitrogen plasma post-treatment. The results of X-ray photoelectron spectroscopy and scanning electron microscopy indicate silicone curing by plasma post-treatment and pore-closing of base paper without changes of the bulk material. The aging test lasting 3 months revealed the stability of the prepared coating. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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9 pages, 3364 KiB

Open AccessArticle

Work Function Tuning of Zinc–Tin Oxide Thin Films Using High-Density O₂ Plasma Treatment

by Young-Hee Joo, Jae-Hyung Wi, Woo-Jung Lee, Yong-Duck Chung, Dae-Hyung Cho, Saewon Kang, Doo-Seung Um and Chang-Il Kim

Coatings 2020, 10(11), 1026; https://doi.org/10.3390/coatings10111026 - 25 Oct 2020

Cited by 16 | Viewed by 4461

Abstract

Work function tuning has a significant influence on the performance of semiconductor devices, owing to the formation of potential barriers at the interface between metal-semiconductor junctions. In this work, we introduce a technique for tuning the work function of ZnSnO thin films using [...] Read more.

Work function tuning has a significant influence on the performance of semiconductor devices, owing to the formation of potential barriers at the interface between metal-semiconductor junctions. In this work, we introduce a technique for tuning the work function of ZnSnO thin films using high-density O₂ plasma treatment. The work function and chemical composition of the ZnSnO thin film surfaces were investigated with regards to plasma treatment time through UPS/XPS systems. The optical band gap was estimated using Tauc’s relationship from transmittance data. The work function of Zn_0.6Sn_0.4O thin film increased from 4.16 eV to 4.64 eV, and the optical band gap increased from 3.17 to 3.23 eV. The surface of Zn_0.6Sn_0.4O thin films showed a smooth morphology with an average of 0.65 nm after O₂ plasma treatment. The O₂ plasma treatment technique exhibits significant potential for application in high-performance displays in optical devices, such as thin-film transistors (TFTs), light-emitting diodes (LEDs), and solar cells. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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12 pages, 2445 KiB

Open AccessArticle

Effects of Bias Voltages on the Structural, Mechanical and Oxidation Resistance Properties of Cr–Si–N Nanocomposite Coatings

by Yanxiong Xiang, Lingling Huang and Changwei Zou

Coatings 2020, 10(8), 796; https://doi.org/10.3390/coatings10080796 - 18 Aug 2020

Cited by 10 | Viewed by 2743

Abstract

Cr–Si–N nanocomposite coatings were deposited by multi-arc ion plating under different bias voltages. The influences of bias voltage on composition, microstructure, surface morphology and mechanical properties of Cr–Si–N nanocomposite coatings were investigated in detail. The HR-TEM, XRD, and XPS results confirmed the formation [...] Read more.

Cr–Si–N nanocomposite coatings were deposited by multi-arc ion plating under different bias voltages. The influences of bias voltage on composition, microstructure, surface morphology and mechanical properties of Cr–Si–N nanocomposite coatings were investigated in detail. The HR-TEM, XRD, and XPS results confirmed the formation of nanocomposite structure of nanocrystalline of CrN embedded into the amorphous phase of Si₃N₄. The particle radius of CrN can be calculated from the half-width of the diffraction peak of CrN (200) and the value was about 20–60 nm. In addition, no diffraction peaks of CrSi₂, Cr₃Si, or Si₃N₄ were found in all the Cr–Si–N coatings. With the increasing of bias voltages from 0 to −200 V, the number and size of large droplets on the coating surface decreased, and the growth mode of the coatings changed from loose to dense. However, with the increasing of bias voltages from 0 to −200 V, the micro-hardness of the coatings increased and then decreased, reaching its maximum value at negative bias voltages of 100 V. It was found that the friction coefficient of Cr–Si–N coatings is almost the same except for the Cr–Si–N coatings deposited under bias voltage of 0 V. When the oxidation temperature was at 800 °C, the Cr–Si–N coating was only partially oxidized. However, with the increase of oxidation temperature to 1200 °C, the surface of the coating was completely covered by the oxide generated. The results showed that the bias voltages used in multi-arc ion plating had effects on the structure, mechanical, and high temperature oxidation resistance properties of Cr–Si–N nanocomposite coatings. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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9 pages, 3765 KiB

Open AccessArticle

Etching Characteristics of Si_xN_y Film on Textured Single Crystalline Silicon Surface Using Ar/CF₄ and He/CF₄ Surface-Discharge Plasma

by Toshiyuki Hamada, Shunsuke Masuda, Kazuki Nishida and Soma Yamamoto

Coatings 2020, 10(6), 563; https://doi.org/10.3390/coatings10060563 - 14 Jun 2020

Cited by 5 | Viewed by 2700

Abstract

In this study, we investigated the characteristics of electrode grooves formed by etching silicon nitride (Si_xN_y) films using surface-discharge plasma under Ar/CF₄ and He/CF₄ gases on the basis of differences in the widths of the electrode grooves [...] Read more.

In this study, we investigated the characteristics of electrode grooves formed by etching silicon nitride (Si_xN_y) films using surface-discharge plasma under Ar/CF₄ and He/CF₄ gases on the basis of differences in the widths of the electrode grooves etched on the Si_xN_y film. The widths of the grooves etched using Ar as the carrier gas were narrower than those etched using He, and the etching speed achieved using Ar was higher than that achieved using He. Furthermore, the electrode groove created by surface-discharge plasma gradually widened as etching time and applied voltage increased. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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10 pages, 2146 KiB

Open AccessArticle

Assessment of Potential of the High-Voltage Anodic Plasma Source to Deposit Multilayer Structures Relevant to X-ray Mirror Applications

by Aurel-Mihai Vlaicu, Alexandru Anghel, Marius Badulescu and Cristina Surdu-Bob

Coatings 2020, 10(6), 531; https://doi.org/10.3390/coatings10060531 - 30 May 2020

Viewed by 2169

Abstract

(1) Background: The high-voltage anodic-plasma (HVAP) coating technique has a series of specificities that are not simultaneously met in other deposition methods. This paper aimed at assessing the potential of HVAP to synthesize quality multilayers for X-ray optics. (2) Methods: Nanolayers of W, [...] Read more.

(1) Background: The high-voltage anodic-plasma (HVAP) coating technique has a series of specificities that are not simultaneously met in other deposition methods. This paper aimed at assessing the potential of HVAP to synthesize quality multilayers for X-ray optics. (2) Methods: Nanolayers of W, Ta, B, and Si were deposited as mono-, bi-, and multilayers onto very smooth glass substrates by HVAP, and their thickness and density were analyzed by X-ray reflectometry. The minimal film thickness needed to obtain continuous nanolayers was also investigated. (3) Results: Nanolayer roughness did not increase with layer thickness, and could be lowered via deposition rate, with values as low as 0.6 for the W nanolayer. Minimal film thickness for continuous films for the studied metals was 4 nm (W), 6 nm (Ta), 2.5 nm (B), and 6 nm (Si). (4) Conclusions: The investigation revealed the range of parameters to be used for obtaining quality nanolayers and multilayers by HVAP. Advantages and possible improvements are discussed. This deposition technique can be tailored for demanding applications such as X-ray mirrors. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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14 pages, 12502 KiB

Open AccessArticle

Yttrium Oxyfluoride Coatings Deposited by Suspension Plasma Spraying Using Coaxial Feeding

by Jaehoo Lee, Seungjun Lee, Heung Nam Han, Woongsik Kim and Nong-Moon Hwang

Coatings 2020, 10(5), 481; https://doi.org/10.3390/coatings10050481 - 16 May 2020

Cited by 16 | Viewed by 6375

Abstract

The recently discovered yttrium oxyfluoride (YOF) coating has been found to be a highly promising plasma-resistant material which can be coated onto the inner wall of the dry etching chambers used in the manufacturing of the three-dimensional stacking circuits of semiconductors, such as [...] Read more.

The recently discovered yttrium oxyfluoride (YOF) coating has been found to be a highly promising plasma-resistant material which can be coated onto the inner wall of the dry etching chambers used in the manufacturing of the three-dimensional stacking circuits of semiconductors, such as vertical NAND flash memory. Here, the coating behavior of the YOF coating which was deposited by suspension plasma spraying was investigated using a high-output coaxial feeding method. Both the deposition rate and density of YOF coatings increased with the plasma power, which was determined by the gas ratio of Ar/H₂/N₂ and the arc current. The coating thicknesses were 58 ± 3.4, 25.8 ± 2.1, 5.6 ± 0.6, and 0.93 ± 0.4 µm at plasma powers of 112, 83, 67, and 59 kW, respectively, for 20 scans with a feeding rate of the suspension at 0.045 standard liters per minute (slm). The porosities were 0.15% ± 0.01%, 0.25% ± 0.01%, and 5.50% ± 0.40% at corresponding plasma powers of 112, 83, and 67 kW. High-resolution X-ray diffraction (HRXRD) shows that the major and minor peaks of the coatings which were deposited at 112 kW stem from trigonal YOF and cubic Y₂O₃, respectively. Increasing the flow rate of the atomizing gas from 15 slm to 30 slm decreased the porosity of the YOF coating from 0.22% ± 0.03% to 0.07% ± 0.03%. The Vickers hardness of the YOF coating containing some Y₂O₃ deposited at 112 kW was 550 ± 70 HV. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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9 pages, 2900 KiB

Open AccessArticle

Molecular Dynamics Simulations of Vacancy Generation and Migration near a Monocrystalline Silicon Surface during Energetic Cluster Ion Implantation

by Guoying Liang, Haowen Zhong, Yinong Wang, Shijian Zhang, Mofei Xu, Shicheng Kuang, Jianhui Ren, Nan Zhang, Sha Yan, Xiao Yu, Gennady Efimovich Remnev and Xiaoyun Le

Coatings 2020, 10(2), 146; https://doi.org/10.3390/coatings10020146 - 5 Feb 2020

Cited by 3 | Viewed by 2985

Abstract

The process of ion implantation often involves vacancy generation and migration. The vacancy generation and migration near a monocrystalline silicon surface during three kinds of energetic Si₃₅ cluster ion implantations were investigated by molecular dynamics simulations in the present work. The patterns [...] Read more.

The process of ion implantation often involves vacancy generation and migration. The vacancy generation and migration near a monocrystalline silicon surface during three kinds of energetic Si₃₅ cluster ion implantations were investigated by molecular dynamics simulations in the present work. The patterns of vacancy generation and migration, as well as the implantation-induced amorphous structure, were analyzed according to radial distribution function, Wigner–Seitz cell, and identify diamond structure analytical methods. A lot of vacancies rapidly generate and migrate in primary directions and form an amorphous structure in the first two picoseconds. The cluster with higher incident kinetic energy can induce the generation and migration of more vacancies and a deeper amorphous structure. Moreover, boundaries have a loading–unloading effect, where interstitial atoms load into the boundary, which then acts as a source, emitting interstitial atoms to the target and inducing the generation of vacancies again. These results provide more insight into doping silicon via ion implantation. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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13 pages, 5528 KiB

Open AccessArticle

Correlation of Feedstock Powder Characteristics with Microstructure, Composition, and Mechanical Properties of La₂Ce₂O₇ Coatings Produced by Plasma Spray-Physical Vapor Deposition

by Cong Zhao, Wenting He, Jian He, Liangliang Wei and Hongbo Guo

Coatings 2020, 10(2), 93; https://doi.org/10.3390/coatings10020093 - 22 Jan 2020

Cited by 7 | Viewed by 2497

Abstract

By virtue of plasma spray-physical vapor deposition (PS-PVD) process, coatings in possession of columnar structures can be obtained by suitable processing parameters coupled with specially designed powder feedstock. In this paper, the influence of powder characteristics on the La₂Ce₂O [...] Read more.

By virtue of plasma spray-physical vapor deposition (PS-PVD) process, coatings in possession of columnar structures can be obtained by suitable processing parameters coupled with specially designed powder feedstock. In this paper, the influence of powder characteristics on the La₂Ce₂O₇ (LC) coating microstructures was investigated by using three kinds of feedstock powders with same PS-PVD processing parameters. It was found that small agglomerated feedstock, weak binding strength, and small primary particle sizes can enhance the feedstock evaporation rate, thus obtaining well columnar structured coatings. X-ray diffraction (XRD) patterns revealed that except for a very small amount of La₂O₃ the main phase of all the coatings is LC. The La/Ce atomic ratios reduced in the coatings compared to the feedstocks, especially the coatings with better columnar structure. Super-lattice patterns were observed by transmission electron microscope (TEM), which means that the LC phase is supposed to be pyrochlore structure. Furthermore, the mechanical properties evaluated by nano-indentation tests indicated that both the hardness and Young’s modulus of each coating show negative correlations with the porosity inside the columns. Full article

(This article belongs to the Special Issue Plasma Surface Engineering)

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