scholarly journals Collisional Effects of Background Gases on Pulsed Laser Deposition Plasma Beams

1995 ◽  
Vol 388 ◽  
Author(s):  
David B. Geohegan ◽  
Alex A. Puretzky
Keyword(s):  
Pulsed Laser Deposition ◽  
Film Growth ◽  
Pulsed Laser ◽  
Target Material ◽  
Ion Flux ◽  
Fast Component ◽  
Laser Deposition ◽  
Optical Absorption Spectroscopy ◽  
Single Element ◽  
General Effect

AbstractThe penetration of energetic pulsed ablation plumes through ambient gases is experimentally characterized to investigate a general phenomenon believed to be important to film growth by pulsed laser deposition (PLD). Under typical PLD conditions involving background gases, the ion flux in the ablation plume is observed to split into distinct fast and slow components over a limited range of distances1,2 the fast component is transmitted with near-initial velocities and high kinetic energies, potentially damaging to growing films at these distances. Formation of the second, significantly-slowed component correlates with the bright contact front3 formation observed1,4 in fast ICCD imaging studies. This general effect is explored in detail for the case of yttrium ablation into argon, a single-element target into an inert gas.5 Time-resolved optical absorption spectroscopy and optical emission spectroscopy are employed to simultaneously view the populations of both excited and ground states of Y and Y+ for comparison with quantitative intensified-CCD photography of the visible plume luminescence and ion flux measurements made with fast ion probes during this phenomenon. these measurements confirm that, in addition to the bright significantly-slowed front which has been described by shock or drag propagation models1, a fast-component of target material is transmitted to extended distances for some ambient pressures with near-initial velocities.

Low Temperature Growth of Oriented Gallium Nitride using Pulsed Laser Deposition

1995 ◽  
Vol 395 ◽  
Author(s):  
Robert Leuchtner ◽  
W. Brock ◽  
Y. Li ◽  
L. Hristakos
Keyword(s):  
Pulsed Laser Deposition ◽  
Film Growth ◽  
Ambient Pressure ◽  
Pulsed Laser ◽  
Target Material ◽  
Deposition Process ◽  
Film Deposition ◽  
Laser Deposition ◽  
Metal Target ◽  
X Ray

ABSTRACTOriented GaN has been successfully grown at low substrate temperatures (∼480°C) on a- and r-planes of sapphire, using the pulsed laser deposition process. We have examined the effects of several deposition parameters on film growth, including substrate temperature (∼50–500°C), ambient pressure (1×10−3 – 10 torr of NH3), and target material (Ga or GaN). The film deposition rate was typically ∼3–4 μm/hr. Film characterization was performed using x-ray diffraction (XRD), optical microscopy, x-ray photoelectron spectrometry (XPS), and atomic force microscopy (AFM). In the case of the Ga metal target, a plasma (∼500V) between the target and substrate was necessary to promote formation of the GaN phase. The ammonia ambient enhanced the nitrogen content in the films compared to vacuum deposition. In general, the GaN target yielded better quality films (smaller rocking curve widths and smoother film morphology) compared to the Ga metal target. These results suggest that pulsed laser deposition is a promising approach to fabricating high quality films of this potentially important semiconducting material.

The Influence of Deposition Pressure on the Incorporation of Target and Ambient Oxygen Into Laser Ablated Material

1993 ◽  
Vol 311 ◽  
Author(s):  
M. Zhu Tidrow ◽  
S.S. Tidrow ◽  
W.W. Wilber ◽  
R.R. Pfeffer
Keyword(s):  
Pulsed Laser Deposition ◽  
Film Growth ◽  
Pulsed Laser ◽  
Target Material ◽  
Laser Deposition ◽  
Chamber Pressure ◽  
Ambient Atmosphere ◽  
Deposition Pressure ◽  
Amorphous Films ◽  
Ambient Oxygen

ABSTRACTOxygen plays an essential role in the growth of a variety of oxides such as high-Tc superconductors, ferroelectrics, ferrites and dielectrics. The oxygen available for film growth during laser ablation can come from two sources: the target material and the ambient deposition atmosphere. The amount of oxygen incorporated from these two sources at room temperature has been investigated over a range of deposition pressures. Thiswas accomplished using 18O as a tracer during pulsed laser deposition of amorphous filmsfrom Cu and CuO targets. It was found that the total amount of oxygen incorporated by the amorphous films increases with chamber pressure up to approximately 35 mTorr. For pulsed laser deposition from the oxide target, the major fraction of the oxygen within the deposited material comes from the target. For the oxide target, the amount of oxygen incorporated from the ambient atmosphere is strongly pressure dependent with a maximum near 35 mTorr. These results are compared to earlier work with YBa2Cu3O7.

Mullite Diffusion Barriers for SiC-C/C Composites Produced by Pulsed Laser Deposition

1998 ◽  
Vol 555 ◽  
Author(s):  
H. Fritze ◽  
A. Schnittker ◽  
T. Witke ◽  
C. Rüscher ◽  
S. Weber ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Target Material ◽  
High Energy ◽  
Single Step ◽  
Laser Deposition ◽  
Reduced Pressure ◽  
Oxidation Rates ◽  
Energy Impact ◽  
Diffusion Parameters

AbstractPulsed Laser Deposition (PLD) allows the ablation of nonconductive and high melting point target materials and the preparation of films with complex composition. High energy impact leads to melting and evaporation of the target material in a single step. In case of mullite ablation, the flux of the metal components is stoichiometric. Under reduced pressure the oxygen content in the layers decreases. However, after a short oxidation treatment, the formation of mullite in the coating is completed, as confirmed by IR spectroscopy and XRD investigations. For a commercial Si-SiC precoated C/C material, the effectiveness of additional PLD mullite layers as outer oxidation protection is tested in the temperature range 773 K < T < 1873 K. Mullite coatings with a thickness of 2.5 pm improve the oxidation behaviour significantly. Because of SiO2 formation at the mullite-SiC interface, all samples exhibited a mass increase upon oxidation. For oxidation durations of three days, only amorphous SiO2 is formed at the mullite-SiC interface. The inward diffusion of oxygen across the outer mullite-containing layer controls the kinetics of the reaction, as was deduced from 18O diffusivity measurements in PLD mullite layers. At temperatures close to the eutectic temperature (1860 K), mullite can seal defects. The calculated oxidation rates resulting from the diffusion parameters in SiO2 and mullite are close to the thermogravimetric data.

Tracing the origin of oxygen for La0.6Sr0.4MnO3thin film growth by pulsed laser deposition

2015 ◽  
Vol 49 (4) ◽  
pp. 045201 ◽  
Author(s):  
J Chen ◽  
M Döbeli ◽  
D Stender ◽  
M M Lee ◽  
K Conder ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Film Growth ◽  
Pulsed Laser ◽  
Laser Deposition

Microstructure of Compositionally Graded PZT films Grown by Pulsed Laser Deposition

2008 ◽  
Vol 14 (S3) ◽  
pp. 53-56
Author(s):  
S.A.S. Rodrigues ◽  
A. Khodorov ◽  
M. Pereira ◽  
M.J.M. Gomes
Keyword(s):  
Pulsed Laser Deposition ◽  
Lead Zirconate Titanate ◽  
Film Growth ◽  
Pulsed Laser ◽  
Hysteresis Loops ◽  
Lead Zirconate ◽  
Laser Deposition ◽  
Composition Gradient ◽  
Complex Structures ◽  
Pzt Films

Ferroelectric films with a composition gradient have attracted much attention because of their large polarization offset present in the hysteresis loops. Lead Zirconate Titanate (PZT) films were deposited on Pt/TiO2/SiO2/Si substrates by Pulsed Laser Deposition (PLD) technique, using a Nd:YAG laser (Surelite) with a source pulse wavelength of 1064 nm and duration of 5-7 ns delivering an energy of 320 mJ per pulse and a laser fluence energy about 20 J/cm2. The film growth is performed in O2 atmosphere (0,40 mbar) while the substrate is heated at 600°C by a quartz lamp. Starting from ceramic targets based on PZT compositions and containing 5% mol. of excess of PbO to compensate the lead evaporation during heat treatment, three films with different compositions Zr/Ti 55/45, 65/35 and 92/8, and two types of complex structures were produced. These complex structures are in the case of the up-graded structure (UpG), with PZT (92/8) at the bottom, PZT (65/35) on middle and PZT (55/45) on the top, and for down-graded (DoG) one, that order is reversed.

ZnSe and ZnO film growth by pulsed-laser deposition

1998 ◽  
Vol 127-129 ◽  
pp. 496-499 ◽  
Author(s):  
Y.R. Ryu ◽  
S. Zhu ◽  
S.W. Han ◽  
H.W. White ◽  
P.F. Miceli ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Film Growth ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Zno Film

Incongruent pulsed laser deposition strategy for thin film growth of Ca3Co4O9 thermoelectric compound

2019 ◽  
Vol 45 (10) ◽  
pp. 13138-13143 ◽  
Author(s):  
Haiyang Hu ◽  
Fei Shao ◽  
Jikun Chen ◽  
Max Döbeli ◽  
Qingfeng Song ◽  
...  
Keyword(s):  
Thin Film ◽  
Pulsed Laser Deposition ◽  
Film Growth ◽  
Pulsed Laser ◽  
Thin Film Growth ◽  
Laser Deposition

Ca2RuO4Thin Film Growth by Pulsed Laser Deposition

2004 ◽  
Vol 819 ◽  
Author(s):  
Xu Wang ◽  
Yan Xin ◽  
Hanoh Lee ◽  
Patricia A. Stampe ◽  
Robin J. Kennedy ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Electrical Transport ◽  
Film Growth ◽  
Pulsed Laser ◽  
High Sensitivity ◽  
Laser Deposition ◽  
Chemical Doping ◽  
Bulk Single Crystal ◽  
Electrical Transport Properties

AbstractBulk Ca2RuO4 is an antiferromagnetic Mott insulator with the metal-insulator transition above room temperature, and the Neel temperature at 113 K. There is strong coupling between crystal structures and magnetic, electronic phase transitions in this system. It exhibits high sensitivity to chemical doping and pressure that makes it very interesting material to study. We have epitaxially grown Ca2RuO4 thin films on LaAlO3 substrates by pulsed laser deposition technique. Growth conditions such as substrate temperature and O2 pressure were systematically varied in order to achieve high quality single-phase film. Crystalline quality and orientation of these films were characterized by X-ray diffractometry. Microstructure of the thin films was examined by transmission electron microscopy. The electrical transport properties were also measured and compared with bulk single crystal.

Epitaxial Growth of TiN on GaAs(100) by Pulsed Laser Deposition

1992 ◽  
Vol 285 ◽  
Author(s):  
Tsvetanka S. Zheleva ◽  
K. Jagannadham ◽  
A. Kumar ◽  
J. Narayan
Keyword(s):  
High Resolution ◽  
Pulsed Laser Deposition ◽  
Epitaxial Growth ◽  
Film Growth ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Tin Films ◽  
High Resolution Tem

ABSTRACTEpitaxial growth of TiN films on GaAs(100) by pulsed laser deposition has been studied. Excimer KrF laser (λ=248 nm, τ=30 ns) has been used for deposition of TiN films in a chamber maintained at vacuum of ≤ 10−6 torr. The microstructure of TiN films has been characterized by x-ray diffraction and transmission electron microscopy (TEM). Cross-sectional high resolution TEM showed a smooth unreacted interface between the single crystalline TiN film and GaAs. The predominant epitaxial relationship was found to be [110]TiN//[010]GaAs, (220)TiN//(040)GaAs at a substrate temperature of 350°C. Modelling of epitaxial growth showed that the interfacial energy is an important term responsible for 45° rotation of the TiN unit cell with respect to that of GaAs. The high strain energy associated with the coherent epilayer is reduced by domain epitaxial growth. These films were characterized using high-resolution TEM techniques, and experimental results were rationalized by thin film growth modeling.

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