Laser-Ablation of Various Oxide Materials Over Large Areas

1990 ◽  
Vol 191 ◽  
Author(s):  
James A. Greer ◽  
H. Jerrold Van Hook
Keyword(s):  
Laser Ablation ◽  
Physical Vapor Deposition ◽  
Film Growth ◽  
High Energy ◽  
Published Report ◽  
Device Applications ◽  
Novel Method ◽  
Reactive Gases ◽  
Infrared Materials

Laser-Ablation (LA) had received little attention prior to the first published report of depositing Y1Ba2Cu3O7-x) (YBCO) thin films with this novel method.[1] However, LA has been used to produce films of infrared materials for some time[2], and the recent discovery of 1-igh Temperature Superconductors (HITS) has sparked considerable interest in this relatively obscure Physical Vapor Deposition (PVD) technique. Over the past three years, a variety of in-situ LA processes for producing films of HTS compounds, as well as other materials, have been reported in the literature.[3,4,5,6,7] Like any other PVD technique, LA has its own unique advantages anid disadvantages. The main advantages of LA include: 1) its ability to accurately replicate the stoichiometry of the ablation target within the laser-deposited film; 2) the high energy of the ablated species which may enhance the quality of film growth; 3) it does not require hot filaments which allow a number of reactive gases to be present in the chamber during deposition; and 4) a wide array of complex chemical compounds can be deposited. Two of the main problems facing this emerging PVD technique have been: 1) it has been applied mostly to small area deposition (<6 cm2) with poor uniformity, and 2) the ablated films typically display a large number- of particles ranging in size from 0.5 μm to over 10 μm, whose presence may significantly hamper a number of microelectronic device applications.

Modifications of a JEOL 2000EX TEM for insSitu surface studies

1993 ◽  
Vol 51 ◽  
pp. 640-641
Author(s):  
Michael T. Marshall ◽  
Xianghong Tong ◽  
J. Murray Gibson
Keyword(s):  
Electron Diffraction ◽  
Surface Science ◽  
Film Growth ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Transmission Electron ◽  
Fundamental Insight

We have modified a JEOL 2000EX Transmission Electron Microscope (TEM) to allow in-situ ultra-high vacuum (UHV) surface science experiments as well as transmission electron diffraction and imaging. Our goal is to support research in the areas of in-situ film growth, oxidation, and etching on semiconducter surfaces and, hence, gain fundamental insight of the structural components involved with these processes. The large volume chamber needed for such experiments limits the resolution to about 30 Å, primarily due to electron optics. Figure 1 shows the standard JEOL 2000EX TEM. The UHV chamber in figure 2 replaces the specimen area of the TEM, as shown in figure 3. The chamber is outfitted with Low Energy Electron Diffraction (LEED), Auger Electron Spectroscopy (AES), Residual Gas Analyzer (RGA), gas dosing, and evaporation sources. Reflection Electron Microscopy (REM) is also possible. This instrument is referred to as SHEBA (Surface High-energy Electron Beam Apparatus).The UHV chamber measures 800 mm in diameter and 400 mm in height. JEOL provided adapter flanges for the column.

A novel method for in-situ synthesized TiN coatings by plasma spray-physical vapor deposition

2018 ◽  
Vol 217 ◽  
pp. 127-130 ◽  
Author(s):  
Chen Song ◽  
Min Liu ◽  
Zi-Qian Deng ◽  
Shao-Peng Niu ◽  
Chun-Ming Deng ◽  
...  
Keyword(s):  
Plasma Spray ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Tin Coatings ◽  
Novel Method

In situ quantitative analysis of GeXSi1-X alloys during growth by reflection EELS

1991 ◽  
Vol 49 ◽  
pp. 878-879
Author(s):  
Shouleh Nikzad ◽  
Channing C. Ahn ◽  
Harry A. Atwater
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Film Growth ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Mbe Growth ◽  
Electron Microscopes ◽  
Electron Energy Loss

The universality of reflection high energy electron diffraction (RHEED) as a structural tool during film growth by molecular beam epitaxy (MBE) brings with it the possibility for in situ surface chemical analysis via spectroscopy of the accompanying inelastically scattered electrons. We have modified a serial electron energy loss spectrometer typically used on an electron microscope to work with a 30 keV RHEED-equipped MBE growth chamber in order to determine the composition of GexSi1-x alloys by reflection electron energy loss (REELS) experiments. Similar work done in transmission electron microscopes has emphasized the surface sensitivity of this technique even though these experiments have never been done under ultra-high vacuum conditions. In this work, we are primarily concerned with the accuracy with which core losses can be used to determine composition during MBE growth.

In Situ Growth of High Quality Epitaxial Yba2cu3O7‐X Thin Films at Moderate Temperatures by Pulsed Laser Ablation

1989 ◽  
Vol 169 ◽  
Author(s):  
Douglas H. Lowndes ◽  
David P. Norton ◽  
J. W. Mccamy ◽  
R. Feenstra ◽  
J. D. Budai ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Film Growth ◽  
Laser Energy ◽  
Thickness Variation ◽  
In Situ Growth ◽  
High Quality ◽  
Higher Temperature ◽  
Laser Beam Scanning ◽  
Rotating Target

AbstractPulsed KrF (248 nm) laser ablation has been used for in situ growth of smooth, high‐quality YBa2Cu3O7‐x epitaxial films of variable thickness on SrTiO3, KTaO3, LaGaO3, LaA1O3, cubic ZrO2, and MgO substrates, at temperatures of ∼60O‐730°C, without higher temperature post‐annealing. A rotating target pellet, fine focusing by a single cylindrical lens, laser‐beam scanning over the target, and laser energy densities ∼2.5‐3 J/cm2 can be combined to yield films of completely uniform composition and with ∼25% thickness variation over areas ∼8 cm2. The best films have Tc > 92 K and JC(H = 0, T = 77 K) > 2 MA/cm2. Film‐growth procedures are described, together with results of superconducting and normal‐state transport measurements.

scholarly journals Thin film stress and microstructure analysis by energy-dispersive diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C724-C724
Author(s):  
Christoph Genzel
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Residual Stress ◽  
Film Growth ◽  
High Energy ◽  
Energy Dispersive ◽  
Film Stress ◽  
Ex Situ ◽  
Near Surface

The most important advantage of energy dispersive (ED) diffraction compared with angle dispersive methods is that the former provides complete diffraction patterns in fixed but arbitrarily selectable scattering directions. Furthermore, in experiments that are carried out in reflection geometry, the different photon energies E(hkl) of the diffraction lines in an ED diffraction pattern can be taken as an additional parameter to analyze depth gradients of structural properties in the materials near surface region. For data evaluation advantageous use can be made of whole pattern methods such as the Rietveld method, which allows for line profile analysis to study size and strain broadening [1] or for the refinement of models that describe the residual stress depth distribution [2]. Concerning polycrystalline thin films, the features of ED diffraction mentioned above can be applied to study residual stresses, texture and the microstructure either in ex-situ experiments or in-situ to monitor, for example, the chemical reaction pathway during film growth [3]. The main objective of this talk is to demonstrate that (contrary to a widespread opinion) high energy synchrotron radiation and thin film analysis may fit together. The corresponding experiments were performed on the materials science beamline EDDI at BESSY II which is one of the very few instruments worldwide that is especially dedicated to ED diffraction. On the basis of selected examples it will be shown that specially tailored experimental setups allow for residual stress depth profiling even in thin films and multilayer coatings as well as for fast in situ studies of film stress and microstructure evolution during film growth.

Magnetic and Electronic Properties of Fe0.1Sc0.9N/ScN(001)/MgO(001) Films Grown by Radio-Frequency Molecular Beam Epitaxy

2009 ◽  
Vol 1198 ◽  
Author(s):  
Costel Constantin ◽  
Kangkang Wang ◽  
Abhijit Chinchore ◽  
Han-Jong Chia ◽  
John Markert ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Radio Frequency ◽  
Buffer Layer ◽  
Rough Surface ◽  
Quantum Interference ◽  
Molecular Beam ◽  
Film Growth ◽  
Magnetic Measurements ◽  
High Energy

AbstractFe0.1Sc0.9N with a thickness of ˜ 380 nm was grown on top of a ScN(001) buffer layer of ˜ 50 nm, grown on MgO(001) substrate by radio-frequency N-plasma molecular beam epitaxy (rf-MBE). The buffer layer was grown at TS ˜ 800 oC, whereas the Fe0.1Sc0.9N film was grown at TS ˜ 420 oC. In-situ reflection high-energy electron diffraction measurements show that the Fe0.1Sc0.9N film growth starts with a combination of spotty and streaky pattern [indicative of a combination of smooth and rough surface]. After ˜ 10 minutes of growth, the pattern converts to a spotty one [indicative of a rough surface]. Towards the end of the Fe0.1Sc0.9N film growth, the spotty patterns transform into even spottier, but also ring-like indicating a polycrystalline behavior. Superconducting quantum interference device magnetic measurements show a ferromagnetic to paramagnetic transition of TC ˜ 370 – 380 K. We calculated a magnetic moment per atom of μ(Fe0.1Sc0.9N) = 0.037 Bohr magneton/ Mn-atom. Based on the carrier concentration measurements (nS(Fe0.1Sc0.9N) = 2.086 × 1019 /cm3), we find that iron behaves as an acceptor. Comparisons are made with similar MnScN (001)/ScN(001)/MgO(001) system.

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