Reactive Pulsed Laser Deposition of Microcrystalline Ge-based Thin Films

2003 ◽  
Vol 762 ◽  
Author(s):  
Matthew R. Wills ◽  
Ruth Shinar ◽  
Alan P. Constant

AbstractPulsed laser deposition (PLD) was used to grow microcrystalline thin films of germanium (Ge) and Ge-carbon (Ge,C) alloys on fused quartz and silicon substrates at substrate temperatures 25°C ≤ Ts ≤ 325°C. The films were analyzed structurally with x-ray diffraction (XRD), optically, electrically with four-point probe measurements, and chemically with x-ray photoelectron spectroscopy (XPS). XRD results displayed a varying degree of crystallinity, with the most crystalline films obtained at Ts > 150°C. The resistivity of the Ge films decreased with increasing temperature, displaying a significant decrease for the films deposited at Ts ≥ 230°C. The growth conditions for Ge films served as a starting point for low-temperature deposition of Ge,C alloys with up to 5% C. The effects of Ts and carbon concentration on film properties are discussed.

2003 ◽  
Vol 780 ◽  
Author(s):  
V. Craciun ◽  
D. Craciun ◽  
J. M. Howard ◽  
R. K. Singh

AbstractZrC thin films were grown on Si substrates by the pulsed laser deposition (PLD) technique. X- ray photoelectron spectroscopy, x-ray diffraction and reflectivity, variable angle spectroscopic ellipsometry, and four point probe measurements were used to investigate the composition, density, thickness, surface morphology, optical and electrical properties of the grown structures. It has been found that crystalline films could be grown only by using fluences above 6 J/cm2 and substrate temperatures in excess of 500 °C. For a fluence of 10 J/cm2 and a substrate temperature of 700 °C, highly (100)-textured ZrC films exhibiting a cubic structure (a=0.469 nm) and a density of 6.7 g/cm3 were deposited. The use of a low-pressure atmosphere of C2H2 had a beneficial effect on crystallinity and stoichiometry of the films. All films contained high levels of oxygen contamination, especially in the surface region, because of the rather reactive nature of Zr atoms.


2002 ◽  
Vol 17 (6) ◽  
pp. 1390-1398 ◽  
Author(s):  
A. R. Phani ◽  
J. E. Krzanowski ◽  
J. J. Nainaparampil

Multilayers of TiC/Ti and TiC/B4C have been deposited by pulsed laser deposition. Ti, B4C, and TiC targets were used to deposit multilayer films onto 440C steel and silicon substrates at 40 °C. The structural, compositional, and mechanical properties of the multilayers were examined by x-ray diffraction, x-ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation techniques. Tribological properties were also evaluated using a pin-on-disc friction and wear test. The TiC/Ti films were found to have a crystalline structure, and both (200)TiC/(100)Ti and (111)TiC/(101)Ti orientation relationships were found in these films. In the TiC/B4C films, only the sample with the largest bilayer thickness (25 nm) had significant crystallinity and only the TiC layer was crystalline. X-ray photoelectron spectroscopy depth profiles confirmed the presence of composition modulations in these films. Nanoindentation tests of the TiC/Ti multilayers showed hardness levels exceeding that predicted by the rule-of-mixtures. The TiC/B4C multilayers showed increasing hardness with decreasing bilayer thickness but reached only 22 GPa. The pin-on-disc tests gave friction values ranging from 0.3 to 0.9 for both sets of films. These results were correlated with the degree of crystallinity and grain structure of the films.


2011 ◽  
Vol 383-390 ◽  
pp. 6289-6292
Author(s):  
Jian Ting He ◽  
Bo Xue Tan ◽  
Qin Qin Wei ◽  
Yuan Bin Su ◽  
Shu Lian Yang

ZnO thin films were deposited on n-Si (111) substrates at various oxygen partial pressures by pulsed laser deposition (PLD). X-ray diffraction (XRD), scanning electron microscopy (SEM) were used to analyze the influence of the oxygen partial pressure on the crystallization and morphology of the ZnO thin films. An optimal crystallized ZnO thin film was observed at the oxygen partial pressure of 6.5Pa. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface components and distribution status of various elments in ZnO thin films. It was found that ZnO thin films were grown in Zn-rich state.


1997 ◽  
Vol 12 (6) ◽  
pp. 1433-1436 ◽  
Author(s):  
A. Iembo ◽  
F. Fuso ◽  
E. Arimondo ◽  
C. Ciofi ◽  
G. Pennelli ◽  
...  

RuO2 thin films have been produced on silicon-based substrates by in situ pulsed laser deposition for the first time. The electrical properties, the surface characteristics, the crystalline structure, and the film-substrate interface of deposited samples have been investigated by 4-probe resistance versus temperature technique, scanning electron microscopy, x-ray photoelectron spectroscopy, x-ray diffraction, and transmission electron microscopy, respectively. The films show good electrical properties. The RuO2-substrate interface is very thin (≈3 nm), since it is not degraded by any annealing process. These two characteristics render our films suitable to be used as electrodes in PZT-based capacitors.


1999 ◽  
Vol 14 (6) ◽  
pp. 2355-2358 ◽  
Author(s):  
M. H. Corbett ◽  
G. Catalan ◽  
R. M. Bowman ◽  
J. M. Gregg

Pulsed laser deposition has been used to make two sets of lead magnesium niobate thin films grown on single-crystal h100j MgO substrates. One set was fabricated using a perovskite-rich target while the other used a pyrochlore-rich target. It was found that the growth conditions required to produce almost 100% perovskite Pb(Mg1/3Nb2/3)O3 (PMN) films were largely independent of target crystallography. Films were characterized crystallographically using x-ray diffraction and plan view transmission electron microscopy, chemically using energy dispersive x-ray analysis, and electrically by fabricating a planar thin film capacitor structure and monitoring capacitance as a function of temperature. All characterization techniques indicated that perovskite PMN thin films had been successfully fabricated.


2001 ◽  
Vol 672 ◽  
Author(s):  
X.Y. Chen ◽  
Y.F. Lu ◽  
Z.M. Ren ◽  
L. Zhang ◽  
J.P. Wang ◽  
...  

ABSTRACTThin films of TiNi shape memory alloy (SMA) have been prepared by pulsed-laser deposition (PLD) at different substrate temperatures. The stoichiometry, crystallinity, and morphology of the deposited films were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and atom force microscopy (AFM). The transformation behavior and crystallization temperatures were investigated by differential scanning calorimetry (DSC). It is found that the Ni content of the deposited films ranges from 46.7 to 52.0 at.%. The crystallization temperature of the amorphous films is around 460°C. The activation energy of the crystallization process is determined by Kissinger's method to be 301 kJ/mol. The martensitic transformation temperature of the annealed Ti-51.5 at.% Ni film is –20.8°C.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 777 ◽  
Author(s):  
Angela De Bonis ◽  
Agostino Galasso ◽  
Alessandro Latini ◽  
Julietta V. Rau ◽  
Antonio Santagata ◽  
...  

Chromium borides are promising candidates for several structural applications including protective coatings for materials exposed to corrosive and abrasive environments. In this paper the pulsed laser deposition of chromium diboride-rich thin films has been carried out in vacuum by using a frequency doubled Nd:glass laser with a pulse duration of 250 fs. The films have been deposited at different substrate temperatures and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. Lastly, the film’s hardness has been studied by Vickers indentation technique. The results indicate that only the films deposited at a substrate temperature of 500 °C are crystalline and formed by chromium diboride, together with a certain amount of boron and chromium, which suggests that, as main mechanism, a process taking place on the surface from atoms and ions from the gas phase. This hypothesis has been confirmed by the study of the plasma produced by the ablation process.


2010 ◽  
Vol 518 (18) ◽  
pp. 5173-5176 ◽  
Author(s):  
J.N. Beukers ◽  
J.E. Kleibeuker ◽  
G. Koster ◽  
D.H.A. Blank ◽  
G. Rijnders ◽  
...  

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