scholarly journals Correlation between Substrate Ion Fluxes and the Properties of Diamond-Like Carbon Films Deposited by Deep Oscillation Magnetron Sputtering in Ar and Ar + Ne Plasmas

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 914
Author(s):  
João Oliveira ◽  
Fábio Ferreira ◽  
Ricardo Serra ◽  
Tomas Kubart ◽  
Catalin Vitelaru ◽  
...  

Recently, the use of Ne as a processing gas has been shown to increase the ionization degree of carbon in High Power Impulse Magnetron Sputtering (HiPIMS) plasmas. In this work, time-resolved measurements of the substrate’s current density were carried out in order to study the time evolution of the ionic species arriving at the growing film. The addition of Ne to the plasma resulted in a steep increase of the sp3/sp2 ratio in the films once the Ne contents in the processing atmosphere exceeded 26%. Increasing the Ne content is shown to increase both the total number of C ions generated in the plasmas and the ratio of C/gaseous ions. The time-resolved substrate ion current density was used to evaluate the possibility of substrate biasing synchronizing with the discharge pulses in the HiPIMS process. It is shown that in pure Ar plasmas, substrate biasing should be confined to the time interval between 25 and 40 µs after the pulse starts, in order to maximize the C+/Ar+ ratio bombarding the substrate and minimize the formation of film stresses. However, Ne addition to the processing gas shortens the traveling time of the carbon species towards the substrate, reducing the separation between the gaseous and carbon ion arrival times.

2002 ◽  
Vol 749 ◽  
Author(s):  
H. Langfischer ◽  
S. Harasek ◽  
H. D. Wanzenboeck ◽  
B. Basnar ◽  
E. Bertagnolli

ABSTRACTIn this study we investigate the nucleation and growth mechanisms of tungsten films processed by focused ion beam (FIB) induced chemical vapor deposition. For our investigation we use a 50 keV Ga+ ion beam focused on the substrate target and tungsten hexacarbonyl (W(CO)6) as precursor gas. Mediated by the substrate the energy of the impinging ions leads to the decomposition of the tungsten hexacarbonyl molecules adsorbed on the substrate into volatile parts and nonvolatile residues forming a metal deposit. Time resolved FIB secondary electron microscope imaging in combination with atomic force microscopy reveal first the formation of isolated nuclei and further their coalescence finally resulting in the formation of a contiguous metal layer. Despite the local impacts of the ion beam within the irradiated area of the substrate the localization of the nucleation spots is neither correlated to the spot centers nor to the scan path of the ion beam. After formation, the nanoscale tungsten nuclei preserve their positions and typical shapes during further deposition. Only after merging the nuclei to a contiguous tungsten layer, a further regime of growth sets on which is characterized by deposition of tungsten on a tungsten surface. In this regime the deposition process is determined by the total ion dose and the average current density the samples are subjected to. In this regime, deposition yields up to 3.5 atoms per incident gallium ion are achieved. The contiguous layer quality is determined by Auger electron analysis. The measured growth data were interpreted by adopting the analytic Ruedenauer Steiger approach mainly incorporating ion current density, precursor gas transformation rate, and ion induced sputtering. As a result, the critical ion current density, where ion sputtering exceeds deposition, was identified by the model. Because the model shows excellent agreement with the measurement it should be suitable for further survey concerning focused ion beam process development.


Author(s):  
M. R. McCartney ◽  
J. K. Weiss ◽  
David J. Smith

It is well-known that electron-beam irradiation within the electron microscope can induce a variety of surface reactions. In the particular case of maximally-valent transition-metal oxides (TMO), which are susceptible to electron-stimulated desorption (ESD) of oxygen, it is apparent that the final reduced product depends, amongst other things, upon the ionicity of the original oxide, the energy and current density of the incident electrons, and the residual microscope vacuum. For example, when TMO are irradiated in a high-resolution electron microscope (HREM) at current densities of 5-50 A/cm2, epitaxial layers of the monoxide phase are found. In contrast, when these oxides are exposed to the extreme current density probe of an EM equipped with a field emission gun (FEG), the irradiated area has been reported to develop either holes or regions almost completely depleted of oxygen. ’ In this paper, we describe the responses of three TMO (WO3, V2O5 and TiO2) when irradiated by the focussed probe of a Philips 400ST FEG TEM, also equipped with a Gatan 666 Parallel Electron Energy Loss Spectrometer (P-EELS). The multi-channel analyzer of the spectrometer was modified to take advantage of the extremely rapid acquisition capabilities of the P-EELS to obtain time-resolved spectra of the oxides during the irradiation period. After irradiation, the specimens were immediately removed to a JEM-4000EX HREM for imaging of the damaged regions.


Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1269
Author(s):  
Chin-Chiuan Kuo ◽  
Chun-Hui Lin ◽  
Jing-Tang Chang ◽  
Yu-Tse Lin

Chromium-carbon films were deposited by utilizing reactive high-power impulse magnetron sputtering at different mixture ratios of ethyne and argon atmosphere, and different substrate bias voltages and deposition temperature, with the same pulse frequency, duty cycle, and average power. The microstructure and mechanical properties of the obtained films were compared. The films consist of amorphous or nanocrystalline chromium carbide, hydrogenated amorphous carbon, and minor α-chromium phase. Decreasing the fraction of ethyne increases the content of the α-chromium phase but decreases hydrogenated amorphous carbon phase. The film’s hardness increases by enhancing the negative substrate bias and raising the deposition temperature, which could be attributed to the increase of film density and the Hall–Petch strengthening effect induced by the nanoscale crystallization of the amorphous carbide phase.


2021 ◽  
pp. 2103533
Author(s):  
Rui Liu ◽  
Zhichao Gong ◽  
Jianbin Liu ◽  
Juncai Dong ◽  
Jiangwen Liao ◽  
...  

2017 ◽  
Vol 124 (1) ◽  
Author(s):  
Anton A. Komlev ◽  
Ekaterina A. Minzhulina ◽  
Vladislav V. Smirnov ◽  
Viktor I. Shapovalov

2004 ◽  
Vol 78 (7) ◽  
pp. 1067-1072 ◽  
Author(s):  
V.N. Popok ◽  
I.I. Azarko ◽  
R.I. Khaibullin ◽  
A.L. Stepanov ◽  
V. Hnatowicz ◽  
...  

1999 ◽  
Vol 18 (3) ◽  
pp. 99-109 ◽  
Author(s):  
Yongxin Tang ◽  
Zhenhui Han ◽  
Qizong Qin

Pulsed laser ablation of TiO2 at 355 nm and 532 nm has been investigated using an angleand time-resolved quadrupole mass spectrometric technique. The major ablated species include O (m/e = 16), O2 (m/e = 32), Ti (m/e = 48), TiO (m/e = 64) and TiO2 (m/e = 80). The time-of-flight (TOF) spectra of ablated species are measured for the ionic and neutral ablated species, and they can be fitted by a Maxwell – Boltzmann (M – B) distribution with a center-of-mass velocity. The measured angular distributions of the ionic species (O+ and Ti+) and the neutral species (O and Ti) can be fitted with cos⁡nθ and a cos⁡θ + (1−a)cos⁡nθ, respectively. In addition, a continuous wave oxygen molecular beam is introduced into the ablated plume, and the enhancement of the signal intensities of TiO is observed. It implies that the ablated Ti atoms/ions species can react with ambient oxygen molecules in the gas phase. In the meanwhile, the physicochemical mechanism of pulsed laser ablation of TiO2 is discussed.


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