Effect of silicon addition on surface morphology and structural properties of titanium nitride films grown by reactive unbalanced direct current-magnetron sputtering

2004 ◽  
Vol 19 (2) ◽  
pp. 523-534 ◽  
Author(s):  
Y.G. Shen ◽  
Z-J. Liu ◽  
N. Jiang ◽  
H.S. Zhang ◽  
K.H. Chan ◽  
...  

Thin films of Ti1–x–y Six Ny were produced on unheated Si(100) substrates by reactive unbalanced dc-magnetron sputtering of titanium and silicon in an Ar–N2 gas mixture. The effects of silicon incorporation on surface morphology and structural properties of these films as well as the influence of postdeposition annealing have been studied. These films were characterized ex situ in terms of their core-level electron bonding configuration by x-ray photoelectron spectroscopy, their microstructure by cross-sectional transmission electron microscopy and x-ray diffraction, their hardness by nanoindentation measurements, and their roughening kinetics by atomic force microscopy (AFM) with the scaling analysis. It was found that a linear increase in the Si concentration of the films was observed with increasing Si target current up to 2 A whereas the reverse trend was seen for the Ti concentration. The films consisted of 15–20-nm-sized TiN crystallites embedded in an amorphous SiNx matrix. They had a hardness of about 32.8 GPa with silicon concentration x = 0.1. The improved mechanical properties of Ti1–x–y Six Ny films with the addition of Si into TiN were attributed to their densified microstructure with development of fine grain size and reduced surface roughness. The reduction in grain size has been supported by means of a Monte Carlo simulation that reveals that the average size of TiN grains decreases with the volume fraction of amorphous SiNx approximately according to a power law, showing a reasonable agreement with the experimental results. By applying the height–height correlation functions to the measured AFM images, a steady growth roughness exponent α = 0.89 ± 0.05 was determined for all the films with different Si additions. It was also found that the nanocomposite films were thermodynamically stable up to 800 °C. The effect of thin SiNx layer in stabilizing nanocrystalline TiN structure is also elucidated and explained on the basis of structural and thermodynamic stability.

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 253 ◽  
Author(s):  
Wei-Chun Chen ◽  
Chao-Te Lee ◽  
James Su ◽  
Hung-Pin Chen

Zirconium diboride (ZrB2) thin films were deposited on a Si(100) substrate using pulsed direct current (dc) magnetron sputtering and then annealed in high vacuum. In addition, we discussed the effects of the vacuum annealing temperature in the range of 750 to 870 °C with flowing N2 on the physical properties of ZrB2 films. The structural properties of ZrB2 films were investigated with X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The XRD patterns indicated that the ZrB2 films annealed at various temperatures exhibited a highly preferred orientation along the [0001] direction and that the residual stress could be relaxed by increasing the annealing temperature at 870 °C in a vacuum. The surface morphology was smooth, and the surface roughness slightly decreased with increasing annealing temperature. Cross-sectional TEM images of the ZrB2/Si(100) film annealed at 870 °C reveals the films were highly oriented in the direction of the c-axis of the Si substrate and the film structure was nearly stoichiometric in composition. The XPS results show the film surfaces slightly contain oxygen, which corresponds to the binding energy of Zr–O. Therefore, the obtained ZrB2 film seems to be quite suitable as a buffer layer for III-nitride growth.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 425 ◽  
Author(s):  
Song Zhang ◽  
Tingting Wang ◽  
Ziyu Zhang ◽  
Jun Li ◽  
Rong Tu ◽  
...  

Direct-current magnetron sputtering (DCMS) was applied to prepare vanadium (V) films on Si substrate. The influence of substrate temperature (Ts) and target–substrate distance (Dt–s) on phase structure and surface morphology of V films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscope (AFM) and transmission electron microscopy (TEM). The results show that the crystallinity of the V films increases with increasing Ts and decreasing Dt–s. The film deposited at Ts = 400 °C and Dt–s = 60 mm exhibits the best crystallinity and <111> preferred orientation with a regular tetrahedral surface morphology. Oxidation behavior of the V thin films has also been studied by X-ray photoelectron spectroscopy (XPS).


2011 ◽  
Vol 18 (01n02) ◽  
pp. 23-31 ◽  
Author(s):  
MANUEL GARCÍA-MÉNDEZ ◽  
SANTOS MORALES-RODRÍGUEZ ◽  
SADASIVAN SHAJI ◽  
BINDU KRISHNAN ◽  
PASCUAL BARTOLO-PÉREZ

A set of aluminium nitride ( AlN ) and oxidized AlN ( AlNO ) thin films were grown with the technique of direct current (dc) reactive magnetron sputtering. The main purpose of this investigation is to explore the influence of the oxygen on the structural properties of AlN and AlNO films. The crystalline properties and chemical identification of phases were studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. Electrical properties were analyzed from I-V measurements. It was found that films crystallized under the AlN würzite structure and presented a polycrystalline preferential growth along [0001] direction, perpendicular to substrate. Small amounts of secondary aluminium oxide phases were detected too. The oxide phases can induce defects, which can alter crystallinity of films.


2015 ◽  
Vol 1131 ◽  
pp. 8-11 ◽  
Author(s):  
Thitikorn Boonkoom ◽  
Kittipong Tantisantisom ◽  
Jedsada Manyam

We examined structural properties of nitrogen doped (ZnO:N) thin films prepared by reactive RF magnetron sputtering technique in conjunction with gas timing method. The deposited films were polycrystalline ZnO in wurtzite structure. Morphology of the ZnO:N films could be modified by adjusting gas timing conditions. The x-ray photoelectron spectroscopy (XPS) and extended x-ray absorption fine structure (EXAFS) analysis showed that incorporation of nitrogen may cause structural distortion in the ZnO:N crystal.


2019 ◽  
Vol 26 (08) ◽  
pp. 1950036 ◽  
Author(s):  
B. WEI ◽  
J. L. XUE ◽  
H. T. CAO ◽  
H. G. LI ◽  
F. WEN ◽  
...  

Carbon-doped titania (C:TiO2) films were prepared by reactive magnetron sputtering using CO2 as a carbon source. The as-prepared films were annealed at different temperatures in vacuum condition. A TiO2 film using O2 gas was also prepared for comparisons with C:TiO2. The structure and composition of the as-prepared, the TiO2 films and the annealed C:TiO2 films were analyzed by X-ray diffraction and X-ray photoelectron spectroscopy, whereas the surface morphology of the C:TiO2 films was measured by atomic force microscopy. Furthermore, photocatalytic properties of the films were evaluated by the degradation of methyl orange (MO). The results indicate that the photocatalytic property was improved when carbon was doped into TiO2 films, and the C:TiO2 films consist of anatase and TiO phases. The experimental results of the MO’s degradation confirm that the annealing process at various temperatures can modify the surface morphology of the films and the content of oxygen vacancies in the films. Consequently, the variations in surface topography and oxygen vacancy potentially enhance the photocatalytic activity of TiO2 films.


2020 ◽  
Author(s):  
Jennifer A. Rudd ◽  
Ewa Kazimierska ◽  
Louise B. Hamdy ◽  
Odin Bain ◽  
Sunyhik Ahn ◽  
...  

The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher value products. Herein, we describe the use of porous copper electrodes to catalyze the reduction of carbon dioxide into higher value products such as ethylene, ethanol and, notably, propanol. For <i>n</i>-propanol production, faradaic efficiencies reach 4.93% at -0.83 V <i>vs</i> RHE, with a geometric partial current density of -1.85 mA/cm<sup>2</sup>. We have documented the performance of the catalyst in both pristine and urea-modified foams pre- and post-electrolysis. Before electrolysis, the copper electrode consisted of a mixture of cuboctahedra and dendrites. After 35-minute electrolysis, the cuboctahedra and dendrites have undergone structural rearrangement. Changes in the interaction of urea with the catalyst surface have also been observed. These transformations were characterized <i>ex-situ</i> using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. We found that alterations in the morphology, crystallinity, and surface composition of the catalyst led to the deactivation of the copper foams.


Author(s):  
Xinyue Li ◽  
Marco Fortunato ◽  
Anna Maria Cardinale ◽  
Angelina Sarapulova ◽  
Christian Njel ◽  
...  

AbstractNickel aluminum layered double hydroxide (NiAl LDH) with nitrate in its interlayer is investigated as a negative electrode material for lithium-ion batteries (LIBs). The effect of the potential range (i.e., 0.01–3.0 V and 0.4–3.0 V vs. Li+/Li) and of the binder on the performance of the material is investigated in 1 M LiPF6 in EC/DMC vs. Li. The NiAl LDH electrode based on sodium alginate (SA) binder shows a high initial discharge specific capacity of 2586 mAh g−1 at 0.05 A g−1 and good stability in the potential range of 0.01–3.0 V vs. Li+/Li, which is better than what obtained with a polyvinylidene difluoride (PVDF)-based electrode. The NiAl LDH electrode with SA binder shows, after 400 cycles at 0.5 A g−1, a cycling retention of 42.2% with a capacity of 697 mAh g−1 and at a high current density of 1.0 A g−1 shows a retention of 27.6% with a capacity of 388 mAh g−1 over 1400 cycles. In the same conditions, the PVDF-based electrode retains only 15.6% with a capacity of 182 mAh g−1 and 8.5% with a capacity of 121 mAh g−1, respectively. Ex situ X-ray photoelectron spectroscopy (XPS) and ex situ X-ray absorption spectroscopy (XAS) reveal a conversion reaction mechanism during Li+ insertion into the NiAl LDH material. X-ray diffraction (XRD) and XPS have been combined with the electrochemical study to understand the effect of different cutoff potentials on the Li-ion storage mechanism. Graphical abstract The as-prepared NiAl-NO3−-LDH with the rhombohedral R-3 m space group is investigated as a negative electrode material for lithium-ion batteries (LIBs). The effect of the potential range (i.e., 0.01–3.0 V and 0.4–3.0 V vs. Li+/Li) and of the binder on the material’s performance is investigated in 1 M LiPF6 in EC/DMC vs. Li. Ex situ X-ray photoelectron spectroscopy (XPS) and ex situ X-ray absorption spectroscopy (XAS) reveal a conversion reaction mechanism during Li+ insertion into the NiAl LDH material. X-ray diffraction (XRD) and XPS have been combined with the electrochemical study to understand the effect of different cutoff potentials on the Li-ion storage mechanism. This work highlights the possibility of the direct application of NiAl LDH materials as negative electrodes for LIBs.


Surfaces ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 106-114
Author(s):  
Yannick Hermans ◽  
Faraz Mehmood ◽  
Kerstin Lakus-Wollny ◽  
Jan P. Hofmann ◽  
Thomas Mayer ◽  
...  

Thin films of ZnWO4, a promising photocatalytic and scintillator material, were deposited for the first time using a reactive dual magnetron sputtering procedure. A ZnO target was operated using an RF signal, and a W target was operated using a DC signal. The power on the ZnO target was changed so that it would match the sputtering rate of the W target operated at 25 W. The effects of the process parameters were characterized using optical spectroscopy, X-ray diffraction, and scanning electron microscopy, including energy dispersive X-ray spectroscopy as well as X-ray photoelectron spectroscopy. It was found that stoichiometric microcrystalline ZnWO4 thin films could be obtained, by operating the ZnO target during the sputtering procedure at a power of 55 W and by post-annealing the resulting thin films for at least 10 h at 600 °C. As FTO coated glass substrates were used, annealing led as well to the incorporation of Na, resulting in n+ doped ZnWO4 thin films.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3191
Author(s):  
Arun Kumar Mukhopadhyay ◽  
Avishek Roy ◽  
Gourab Bhattacharjee ◽  
Sadhan Chandra Das ◽  
Abhijit Majumdar ◽  
...  

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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