Development of preferred orientation in polycrystalline AlN thin films deposited by rf sputtering system at low temperature

1997 ◽  
Vol 12 (7) ◽  
pp. 1850-1855 ◽  
Author(s):  
A. Rodríguez-Navarro ◽  
W. Otaño-Rivera ◽  
J. M. García-Ruiz ◽  
R. Messier ◽  
L. J. Pilione

The development of preferred orientation in AlN thin films deposited on silica glass substrates by rf sputtering at low substrate temperature (<150 °C) has been studied. The main factors controlling the preferential orientation of the AlN thin films are the ion-bombardment energies, incidence angle of the arriving particles, and deposition rate. At low pressure, a perpendicular and highly directional energetic ion-bombardment induces an orientation of the crystallites with their c-axis perpendicular to the substrate surface. At higher pressure (>15 mTorr), a spreading in the incidence angle of the arriving particles, due to gas phase collisions, favors the formation of AlN crystal twinning. A change in the preferred orientation of the films from (0001) to (1011) for deposition rates above 1.8 Å/s is observed.

2010 ◽  
Vol 97-101 ◽  
pp. 1768-1771 ◽  
Author(s):  
Dong Hun Kim ◽  
Riichi Murakami ◽  
Yun Hae Kim ◽  
Kyung Man Moon ◽  
Seung Jung An ◽  
...  

In order to study the characteristics of multilayer thin films with a ZnO/ metal/ ZnO structure the manufacture of the thin films was performed by a dc (direct current) magnetron sputtering system on slide glass substrates. The ZnO thin films were manufactured with the thicknesses of 30 nm and 50 nm. Three kinds of metals (Ag, Al and Cu) were deposited with the thicknesses of 4 nm, 8 nm, 12 nm and 16 nm. The electrical and optical properties of the manufactured thin films were then observed. As a result, the multilayer thin films with an Ag layer represented the most excellent electrical conductivity. This is due to the difference in the fundamental electrical properties of each of the metals. The structures of the metal particles deposited on the ZnO thin films were observed by an SEM (scanning electron microscope). The thin films exhibited a continuous structure with regular spaces between the metal particles. This resulted in an increase of transmittance. This is considered by the decrease of scattering and of light absorption on thin films with a continuous structure.


2011 ◽  
Vol 194-196 ◽  
pp. 2305-2311
Author(s):  
Ying Ge Yang ◽  
Dong Mei Zeng ◽  
Hai Zhou ◽  
Wen Ran Feng ◽  
Shan Lu ◽  
...  

In this study high quality of Al doped ZnO (ZAO) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature in order to study the thickness effect upon their structure, electrical and optical properties. XRD results show that the films are polycrystalline and with strongly preferred (002) orientation perpendicular to substrate surface whatever the thickness is. The crystallite size was calculated by Williamson-Hall method, while it increases as the film thickness increased. The lattice stress is mainly caused by the growth process. Hall measurements revealed electrical parameter very dependent upon thickness when the thickness of ZAO film is lower than 700 nm. The resistivity decreased and the carrier concentration and Hall mobility increases as the film thickness increased. When film thickness becomes larger, only a little change in the above properties was observed. All the films have high transmittance above 90% in visible range. Red shift of the absorption edge was observed as thickness increased. The optical energy bandgap decreased from 3.41eV to 3.30 eV with the increase of film thickness.


2010 ◽  
Vol 93-94 ◽  
pp. 413-416 ◽  
Author(s):  
N. Promros ◽  
Boonchoat Paosawatyanyong

A compact dc magnetron sputtering system capable of silver thin films depositions was designed and constructed. The novel small footprint sputtering head with target diameter of 52 mm was constructed utilizing powerful neodymium alloy magnet. Silver metal was sputter-deposited under various powers. Plasma parameters were analyzed by using the sweeping-bias single langmuir probe. The electron temperatures of the plasma glow were constant at approximately 2 eV even with the increasing of input power whereas plasma density increases with the increasing of the input power. The X-ray diffraction analysis (XRD) and scanning electron microscope (SEM) were used to study the crystalline structure and the surface morphology of the obtained silver thin films. Crystalline orientations of (111) and (200) in the silver films deposited on slide glass substrates were revealed from XRD pattern. The highest degrees of (111) and (200) orientations was obtained at the sputtering power between 0.228 and 0.265 Wcm-2. Sub-micron crystalline silver grain structure were observed using SEM micrographs. Facetted grain size and deposition rate of silver thin films increases as the sputtering power increases.


2017 ◽  
Vol 423 ◽  
pp. 957-960
Author(s):  
Abhishek Rakshit ◽  
Arijit Bose ◽  
Debaleen Biswas ◽  
Madhusudan Roy ◽  
Radhaballabh Bhar ◽  
...  

Author(s):  
Mehmet Oguz Guler ◽  
Mirac Alaf ◽  
Deniz Gultekin ◽  
Hatem Akbulut ◽  
Ahmet Alp

Tin oxide has multiple technological applications including Li-ion batteries, gas sensors, optoelectronic devices, transparent conductors and solar cells. In this study tin dioxide (SnO2) thin films were deposited on glass substrates by RF sputtering process in the oxygen (O2) and argon (Ar) plasma medium. The deposition of the thin SnO2 films was carried out by RF sputtering from SnO2 targets. Before deposition the system was evacuated to 10−4 torr vacuum level and backfilled with Ar. The deposition of the nano structured thin SnO2 films have been performed at different gas pressures. The deposition of the SnO2 was both carried out at different pure argon gas pressures and argon/oxygen mediums with varying oxygen partial pressures. The effect of argon and argon/oxygen partial gas pressures on the grain structure and film thickness were analyzed in the resultant thin films. The deposited thin films both on glass and stainless steel substrates were characterized with scanning electron microscopy (SEM), X-ray diffractometry equipped with multi purpose attachment. The grain size of the deposited layer was determined by X-ray analysis. The Atomic Force Microscopy (AFM) technique was also conducted on the some selected coatings to reveal grain structure and growth behaviors.


2021 ◽  
Author(s):  
Bilel Khalfallah ◽  
I. Riahi ◽  
F. Chaabouni

Abstract RF sputtered undoped and Cu doped ZnO (CZO) thin films were deposited on unheated glass substrates using a mixed Cu2O and ZnO powders target at different Cu concentrations of 0, 1, 2, 3 and 4 wt.%. The effects of copper concentration on the structural, electrical, optical and photocatalytic properties of CZO films have been studied. From XRD and Raman spectroscopy studies, it was found that the deposited films were polycrystalline with a predominant hexagonal wurtzite structure along the c-axis perpendicular to the substrate surface. The presence of multiple interference fringes in the transmittance and reflectance spectra shows the good homogeneity of the films. All the films are highly transparent with transparency reaching 80% indicating the possibility to use these films as an optical window. The absorption tail gradually shifted towards a higher wavelength side, which resulted in the decrease of bandgap energy from 3.35 to 3.26 eV. All the sputtered films are highly conductive with a conductivity reaching 104 S.cm− 1.The effect of Cu-doping on the photocatalytic activity of ZnO thin films for the degradation of methylene blue (MB) dye was studied under sunlight irradiation and the results showed that the Cudoping provokes appreciable degradation of MB and reached a maximum for the 1 wt.% Cu doped ZnO film.


2019 ◽  
Vol 27 (01) ◽  
pp. 1950092
Author(s):  
BATOOL AHMADI KHANEGAHI ◽  
HASSAN SEDGHI

In the present work, zinc sulfide thin films were deposited on glass substrates by sol–gel process with different coating speeds 3600, 4800, 6000 and 7200[Formula: see text]rpm. Zinc acetate (Zn(CH3COO)[Formula: see text]H2O) and thiourea (CH4N2S) were used as precursors. Two-methoxyethanol and monoethanolamine were used as solvent and stabilizer, respectively. The optical properties of ZnS thin films such as refractive index, extinction coefficient, dielectric function and optical band gap energy of the films were obtained by spectroscopic ellipsometry (SE) analysis method in the wavelength range of 300–800[Formula: see text]nm. The incidence angle of the layers was kept at 70∘. The measured SE parameters [Formula: see text] and [Formula: see text] are fitted against the designed model by minimizing the mean square error (MSE). Considering the data obtained, it can be deduced that the optical properties of ZnS films are highly influenced by rotation rates. The extinction coefficients of the films were increased with increasing rotation rates of the films. From these results, it is found that the energy gap of the ZnS films increases with increasing rotation rates of the films in the range of 3.13–3.20[Formula: see text]eV.


2021 ◽  
Vol 406 ◽  
pp. 256-264
Author(s):  
Mohammed Mahdi ◽  
M. Kadri

First, the metallic oxides of PbO, TiO2 and ZrO2 were mixed following (2, 1, 1) molar mass respectively. Then 4 samples were separated (S1, S2, S3 and S4). the first one S1 was subjected to calcination treatments at 600, 700 and 800 °C however, the S2 was treated at 700 °C only, the S3 at 800 °C and S4 at 850 °C. The X ray diffraction of the samples reveals important difference in the phases obtained, at 600 °C the quadratic riche phase of PbTiO3 was mainly observed on sample S1, after the treatment at 700 °C and 800°C, the same XRD patterns were obtained with the same peaks positions and the relative intensity. However the S2 revels different pattern from S1 at 700 °C relative to the formation of the Pb(Zr0.75, Ti0.25)O3 Rhombohedral riche phase. The S3 XRD results reveal also different pattern from S1 at 800 °C relative to the formation of Pb (Zr0.58, Ti0.42) O3 near the Morphotropic phase boundary (MPB) and the S4 confirm these finding. Thin films grown from the S1 and S4 used as target in the RF sputtering system, show important difference in the PZT stoichiometry obtained which is relative to Pb (Zr0.44, Ti0.56) located in the quadratic riche phase and Pb (Zr0.52, Ti0.48) O3 near the MPB respectively.


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