ICMCTF 2023 Session B4-4-TuA: Properties and Characterization of Hard Coatings and Surfaces IV

Tuesday, May 23, 2023 1:40 PM in Room Town & Country D
Tuesday Afternoon

Session Abstract Book
(272KB, Apr 25, 2023)
Time Period TuA Sessions | Abstract Timeline | Topic B Sessions | Time Periods | Topics | ICMCTF 2023 Schedule

Start Invited? Item
1:40 PM B4-4-TuA-1 Magnetron Sputter Deposition of Ultrathick Boron Carbide Coatings on Spherical Substrates for Inertial Confinement Fusion
J. B. Merlo, G. V. Taylor, S. J. Shin, L. B. Bayu Aji, J. H. Bae, L. R. Sohngen, S. O. Kucheyev (Lawrence Livermore National Laboratory)

Boron carbide has attractive properties for use as ablator capsules for inertial confinement fusion (ICF). Creating an ultrathick, uniform, defect-free film on a rolling spherical substrate has many challenges, including delamination and fracture due toresidual stress and nodular growth defects, which are believed to originate from particulates deposited onto the film surface during growth. We have systematically studied effects of direct-current (DC) versus radiofrequency (RF) driven magnetron sputter deposition, substrate temperature, chamber pressure, and the target to substrate distance for amorphous boron carbide films deposited on stationary planar substrates. Here, we describe how these deposition parameters are optimized when the process is transferred to coating rolling spherical substrates.

This work was performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344 and by General Atomics under Contract 89233119CNA000063.

2:00 PM B4-4-TuA-2 Corrosion and Electrical Insulation Properties of SiOX Thin Films Deposited by Microwave PECVD
Atreya Danturthi, Rik Drummond Brydson (University of Leeds, UK); Ivan Kolev (Hauzer); Liuquan Yang (University of Leeds, UK); Andrew Bell (University of Leeds); Guizhi Wu (University of Leeds, UK)

Smart sensor technology is currently being developed and incorporated into several industries as part of the Industry 4.0 scheme to optimise energy input to industrial equipment thereby reducing carbon emissions.

These smart sensors applied on wheel bearings of EVs are prone to premature electrical failure due to current passage from dc/ac motors and also corrosion because of exposure to extreme environments. One of the solutions to this problem is developing electrically insulating and corrosion-resistant coatings that could be applied to the existing system. Current research is focussing on Al2O3-based coatings for these applications deposited using plasma spray/ electrolytic oxidation. However, Al2O3 coatings produced using the above methods were porous requiring additional sealing to be useful in insulation and corrosion-resistant applications. Therefore, Si-based coatings using µ-plasma enhanced chemical vapour deposition (PECVD) are being explored in this current study as the properties of silicon-based coatings can be varied through variations of nitrogen, oxygen, and silicon composition and the fact that PECVD is capable of producing denser coatings than PVD. In addition, higher deposition rates can be achieved using precursors such as hexamethyldisiloxane (HMDSO)/ hexamethyldisilazane (HMDSN) due to their high vapour pressures thereby reducing manufacturing cost.

In this study, HMDSO and O2 gases were used to deposit SiOx coatings at varying gas flow ratios (1:12, 1:16, 1:20), µ-powers (2 and 4kW) and coating thicknesses (3 - 10 μm) to study their impact on corrosion & insulation properties. Characterisation techniques such as Calo test, scratch testing, Rockwell C adhesion test, Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, X-ray diffraction were used for characterisation. In addition, cyclic polarisation and electrochemical impedance spectroscopy were used for corrosion behaviour characterisation, and finally I-V measurements to ascertain insulation behaviour. Preliminary corrosion results of all the coated samples showed significant improvement in corrosion resistance compared to bare high-speed steel substrate. In particular, coatings deposited at 4kW (µ-power) and 1:12 (HMDSO:O2) gas flow ratio had very low corrosion currents (a few pA) indicating high corrosion resistance.

2:20 PM Invited B4-4-TuA-3 High-Throughput Methodology for The Realization of High-Entropy High-Dielectric-Constant Ba(Ti,Zr,Ta,Hf,Mo)O3 Film-Based Metal-Oxide-Semiconductor-Related Devices
Kao-Shuo Chang (National Cheng Kung University (NCKU), Taiwan); Van Dung Nguyen (No.1, University Road); Takahiro NAGATA (National Institute for Materials Science)
The use of a high-throughput sputtering technique for the fabrication of high-entropy high-dielectric-constant (high-k) Ba(Ti,Zr,Ta,Hf,Mo)O3 film libraries on Si substrates and sub-nm equivalent-oxide-thickness (EOT) metal-oxide-semiconductor (MOS) devices and metal-oxide-semiconductor field-effect transistors (MOSFETs) will be presented. The elemental variations and amorphous microstructures were characterized using high-throughput X-ray fluorescence (XRF) and X-ray diffraction, respectively. The film library was patterned into 100 MOS configurations, and their dielectric constants and losses were systemically mapped. The MOSFETs after rapid thermal annealing (RTA) exhibited excellent characteristics, including an on/off current ratio of »106 and a saturated field-effect mobility of 288 cm2×V-1×s-1. Small variations in the threshold voltage and negligible changes in the maximum drain current were also under various positive and negative gate-bias stress conditions before and after the RTA. Our results indicated the potential of the Ba(Ti,Zr,Ta,Hf,Mo)O3 films for usein a gate-first process for advanced gate stack-related devices.
3:00 PM B4-4-TuA-5 Effects of Nitrogen Flow Ratio on the Mechanical and Anticorrosive Properties of Co-sputtered (TiZrHfTa)Nx Films
Tzu-Yu Ou (National Taiwan Ocean University, Taiwan); L. Chang (Ming Chi University of Technology, Taiwan); Y. Chen (National Taiwan Ocean University, Taiwan)

In this study, (TiZrHfTa)Nx films were prepared through co-sputtering with four sputter guns. The stoichiometric ratio x of (TiZrHfTa)Nx films was varied by adjusting the reactive gas ratio of fN2 (N2/(N2 + Ar)) at 0, 0.4, and 0.7. With an fN2 of 0, the fabricated metallic Ti0.23Zr0.22Hf0.30Ta0.25 film, namely N00, exhibited a valence electron concentration of 4.25, a bcc phase with lattice constants of 0.3395 nm, a hardness of 8.0 GPa, and a Young’s modulus of 148 GPa. The introduction of N into the TiZrHfTa crystallites transformed the phase from bcc to fcc. N04 [(Ti0.22Zr0.30Hf0.17Ta0.31)N0.83] and N07 [(Ti0.33Zr0.34Hf0.13Ta0.20)N0.88] films were prepared whenfN2 was set at 0.4 and 0.7, respectively. The N04 and N07 films exhibited a common fcc phase with lattice constants of 0.4490 and 0.4464 nm, respectively. The N04 and N07 films exhibited hardness values of 33.2 and 32.2 GPa and Young’s modulus values of 379 and 363 GPa, respectively. The corrosion resistance of (TiZrHfTa)Nx films was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy.

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3:20 PM COMPLIMENTARY REFRESHMENTS IN EXHIBIT HALL
Session Abstract Book
(272KB, Apr 25, 2023)
Time Period TuA Sessions | Abstract Timeline | Topic B Sessions | Time Periods | Topics | ICMCTF 2023 Schedule