Thin Films of Semiconducting SnSi Alloys Grown by Pulsed Laser Deposition

1994 ◽  
Vol 358 ◽  
Author(s):  
Randolph E. Treece ◽  
J. S. Horwitz ◽  
D. B. Chrisey ◽  
J. Tang ◽  
R. S. Williams

ABSTRACTSemiconducting SnxSi1−x (0≤x≤0.6) thin-film alloys have been grown by pulsed laser deposition (PLD). These new materials are amorphous to X-rays and display small positive optical band gaps, suggesting potential applications in solar cells. The tin silicide films were grown by depositing very thin (1–30 Å) alternating atomic layers from individual Sn and Si targets utilizing an automated multi-target holder coupled to a conventional PLD system. The value of x was selected by controlling the thickness of the atomic layers. The films were characterized by X-ray diffraction, optical absorption, Rutherford backscattering spectroscopy, temperature-dependent resistivity, and X-ray photoelectron spectroscopy. Tin segregation is prevented by keeping the Sn layer thickness below a critical value. Compositions beyond x > 0.6 led to semimetallic SnxSi1−x films with tin crystallites.

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.


2010 ◽  
Vol 150-151 ◽  
pp. 908-911 ◽  
Author(s):  
Wei Rao ◽  
Jun Yu

(La0.7Sr0.3)MnO3 (LSMO) thin films were prepared on Si (100) substrate by pulsed laser deposition (PLD). Both structure and surface morphology of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The results indicate that the films grown on Si (100) substrates have a single pseudo cubic perovskite phase structure with a high (100) orientation. The XPS results show that La, Sr and Mn exist mainly in the forms of perovskite structure and a SrO layer was found on outermost surface.


2011 ◽  
Vol 284-286 ◽  
pp. 2191-2197 ◽  
Author(s):  
Hui Fang Xiong ◽  
Tie Dong Cheng ◽  
X.G. Tang ◽  
Jian Chen ◽  
Qiu Xiang Liu

(La0.7Sr0.3)MnO3 (LSMO) thin films were grown on Si (100) substrate by using pulsed laser deposition (PLD) process. Both structure and surface morphology of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. From XRD, the results indicate that the films grown on Si (100) substrates have a single pseudocubic perovskite phase structure with a high (100) orientation. The XPS results show that La, Sr and Mn exist mainly in the forms of perovskite structure and a SrO layer was found on outermost surface. The films resistivity emeasured under room temperature is 6.4´10-4 W×cm.


2005 ◽  
Vol 12 (02) ◽  
pp. 185-195
Author(s):  
M. RUSOP ◽  
T. SOGA ◽  
T. JIMBO

Amorphous carbon nitride films ( a-CN x) were deposited by pulsed laser deposition of camphoric carbon target with different substrate temperatures (ST). The influence of ST on the synthesis of a-CN x films was investigated. The nitrogen-to-carbon (N/C) and oxygen-to-carbon (O/C) atomic ratios, bonding state, and microstructure of the deposited a-CN x films were characterized by X-ray photoelectron spectroscopy and were confirmed by other standard measurement techniques. The bonding states between C and N , and C and O in the deposited films were found to be significantly influenced by ST during the deposition process. The N/C and O/C atomic ratios of the a-CN x films reached the maximum value at 400°C. ST of 400°C was proposed to promote the desired sp 3-hybridized C and the C 3 N 4 phase. The C–N bonding of C–N , C=N and C≡N were observed in the films.


2010 ◽  
Vol 123-125 ◽  
pp. 375-378 ◽  
Author(s):  
Ram Prakash ◽  
Shalendra Kumar ◽  
Chan Gyu Lee ◽  
S.K. Sharma ◽  
Marcelo Knobel ◽  
...  

Ce1-xFexO2 (x=0, 0.01, 0.03 and 0.0 5) thin films were grown by pulsed laser deposition technique on Si and LaAlO3 (LAO) substrates. These films were deposited in vacuum and 200 mTorr oxygen partial pressure for both the substrates. These films were characterized by x-ray diffraction XRD and Raman spectroscopy measurements. XRD results reveal that these films are single phase. Raman results show F2g mode at ~466 cm-1 and defect peak at 489 cm-1 for film that deposited on LAO substrates, full width at half maximum (FWHM) is increasing with Fe doping for films deposited on both the substrates.


1995 ◽  
Vol 401 ◽  
Author(s):  
Sampriti Sen ◽  
E. Ching-Prado ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
J. S. Horwitz ◽  
...  

AbstractA film of Sr0.35Ba0.65TiO3 (SBT) has been grown in situ by pulsed laser deposition on (001) LaAlO3 single crystal. From X-ray diffraction studies the sample is found to be in single phase and well oriented. Raman spectrum of the SBT film shows bands around 178, 219, 296, 513, 571 and 741 cm”. The spectrum is similar to that found in SBT ceramic material, but the frequencies of the phonons are shifted. This can be explained if the film is under stress due to the presence of defects. The bands at 296 and 741cm−1 correspond to the B1 and A1(LO) normal modes of the BaTiO3 (BT) system, and they are representative of the BT tetragonal phase, which at first glance appears to contradict earlier structural symmetry assignment for SBT(x=0.35) film at room temperature. Micro-Raman measurements from different regions of the film indicate that the SBT film is homogeneous. The bands at 296 and 741 cm−1 are broader in comparison to those in BT single crystal and SBT ceramic material. Temperature dependent halfwidths of these modes suggest strong contribution of defects. Temperature dependent results are discussed in terms of anharmonic contributions involving three and four phonon processes as well as defects. Also, the orthorhombic and rhombohedral phase transitions are discussed. Finally, SEM/EDAX and FT-IR techniques have been used for the structural characterization.


2003 ◽  
Vol 780 ◽  
Author(s):  
R. Guerrero-Penalva ◽  
M.H. Farías ◽  
L. Cota-Araiza

AbstractA significant improvement in corrosion resistance of the protecting oxide of alloys has been observed when adding small amounts of reactive elements, such as yttrium, this effect has been called reactive element effect (REE). The general mechanism of the REE has not been determined yet. In this work, we study a growing of a yttrium oxide film and its interaction with the phases η and α that constitutes the alloy Zn-22Al-2Cu named ZinalcoTM The alloy's surface was coated by a pulsed laser deposition technique. The deposit is controlled and characterized by x-ray photoelectron spectroscopy. The mechanism by which the reactive element produce its effects in this alloy is explained by the preferential interaction among the active sites related to the zinc rich phase and enhancing aluminum movement toward the surface where it is oxidized and the protection film formed.


2005 ◽  
Vol 19 (01n03) ◽  
pp. 533-535
Author(s):  
J. H. HAO ◽  
J. GAO

We have developed a process to grow SrTiO 3 ( STO ) thin films showing single (110) orientation directly on Si by means of pulsed laser deposition technique. The growth of STO films directly on Si has been described. The crystallinity of the grown STO films was characterized by X-ray diffraction analysis of θ-2θ scan and rocking curve. Our results may be of interest for better understanding of the growth based on the perovskite oxide thin films on silicon materials.


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.


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