scholarly journals Substrate Heating Measurements in Pulsed Ion Beam Film Deposition

1995 ◽  
Vol 388 ◽  
Author(s):  
J. C. Olson ◽  
M. O. Thompson ◽  
H. A. Davis ◽  
D. J. Rej ◽  
W. J. Waganaar ◽  
...  
Keyword(s):  
Ion Beam ◽  
Substrate Surface ◽  
National Laboratory ◽  
Beam Current ◽  
Film Deposition ◽  
Los Alamos National Laboratory ◽  
Oxygen Ions ◽  
Substrate Heating ◽  
Ion Energies ◽  
Deposited Films

AbstractDiamond-like Carbon(DLC) films have been deposited at Los alamos National Laboratory by pulsed ion beam ablation of graphite targets. the targets are illuminated by an intense beam of hydrogen, carbon, and oxygen ions at a fluence of 15-45 J/cm2. Ion energies are on the order of 350 keV, with beam current rising to 35 kA over a 400 ns ion current pulse.Raman spectra of the deposited films indicate an increasing ratio of sp3 to sp2 bonding as the substrate is moved further away from the target and further off the target normal. Using a thin film platinum resistor at various positions, we have measured the heating of the substrate surface due to the kinetic energy and heat of condensation of the ablated material. Plume power density and energy input are inferred from the temperature measurements. This information is used to determine if substrate heating is responsible for the lack of DLC in positions close to the target and near the target normal.

TiNi Shape Memory Alloys for MEMS: Thin Film Deposition, Thermophysical Properties and Laser Micromachining Characteristics

2007 ◽  
Vol 539-543 ◽  
pp. 3151-3156
Author(s):  
S.T. Davies
Keyword(s):  
Thin Films ◽  
Thermophysical Properties ◽  
Ion Beam ◽  
Thin Film Deposition ◽  
Ion Source ◽  
Film Deposition ◽  
Ion Energies ◽  
Current Densities ◽  
Krf Excimer Laser ◽  
Deposited Films

The growth of TiNi thin films by ion beam sputter deposition using a Kaufmann type ion source is described. Argon ions are used to sputter separate Ti and Ni targets to deposit nearequiatomic TiNi thin films. Typically, ion energies and current densities of 1500 eV and 1 mA cm-2 respectively are used, with an argon overpressure of around 0.05 mtorr, to achieve deposition rates of order 1 μm hr-1. The thermophysical properties of the deposited films were investigated by thermal imaging. Patterning of TiNi films and foils with micrometre resolution using KrF excimer laser ablation at 248 nm wavelength, with beam fluence up to 2.5 J cm-2, 15 ns pulse duration and pulse rates up to 100 Hz has also been investigated.

Effects of Ionized Cluster Beam Bombardment on Epitaxial Metal Film Deposition on Silicon Substrates

1988 ◽  
Vol 128 ◽  
Author(s):  
Isao Yamada
Keyword(s):  
Room Temperature ◽  
Lattice Mismatch ◽  
Ion Beam ◽  
Substrate Surface ◽  
Metal Films ◽  
Epitaxial Films ◽  
Film Structure ◽  
Film Deposition ◽  
Cluster Beam ◽  
Tem Analysis

ABSTRACTThe effects of ion beam bombardment during ionized cluster beam (ICB) deposition of metal films on Si(111) and Si(100) substrates have been discussed. In the case of Al deposition, films have been epitaxially deposited on Si(lll) and Si(100) substrates at near room temperature. On Si(111) substrates, nearly perfect Al single crystal films could be formed. On Si(100) substrates, Al bicrystals have been grown epitaxially. A remarkable fact concerning these results is that the epitaxial films could be formed at nearly room temperature and on a large lattice mismatch (25%) substrate surface. Atomic resolution TEM analysis suggests that the epitaxy of Al occurs not only on Si surfaces but also at Al/Al grain boundaries. These epitaxial films exhibit extremely high thermal stability and long electromigration life time. To understand the deposition features and film characteristics, the effects of ICB bombardment on the film growth at the initial stage of the deposition and the resultant film structure have been studied. The results show that the role of very low energy ion bombardment is especially important in forming epitaxial metal films. Depositions of Au and Cu on Si substrates have also been made to understand whether ICB deposition may improve the characteristics of other metal films. Preliminary results of these film depositions are also obtained.

In sito Ion Beam Analysis of Radiation Damage Kinetics in MgTiO3 Single Crystals at 170-470 K

1995 ◽  
Vol 396 ◽  
Author(s):  
Ning Yu ◽  
Jeremy N. Mitchell ◽  
Kurt E. Sickafus ◽  
Michael Nastasi
Keyword(s):  
Radiation Damage ◽  
Single Crystals ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Los Alamos National Laboratory ◽  
Beam Analysis ◽  
Radiation Resistant ◽  
Threshold Doses

AbstractRadiation damage kinetics in synthetic MgTiO3 (geikielite) single crystals have been studied using the in situ ion beam facility at Los Alamos National Laboratory. The geikielite samples were irradiated at temperatures of 170, 300, and 470 K with 400 keV xenon ions and the radiation damage was sequentially measured with Rutherford backscattering using a 2 MeV He ion beam along a channeling direction. Threshold doses of 1 and 5×1015 Xe/cm2 were determined for the crystalline-to-amorphous transformation induced by Xe ion irradiation at 170 and 300 K, respectively. However, geikielite retained its crystallinity up to a dose of 2.5x1016 Xe/cm2 at the irradiation temperature of 470 K. This study has shown that MgTiO3, which has a corundum derivative structure, is another radiation resistant material that has the potential for use in radiation environments.

Preparation of molybdenum nitride thin films by N+ ion implantation

1992 ◽  
Vol 7 (2) ◽  
pp. 374-378 ◽  
Author(s):  
J-G. Choi ◽  
D. Choi ◽  
L.T. Thompson
Keyword(s):  
Thin Films ◽  
Ion Beam ◽  
Substrate Surface ◽  
Molybdenum Nitride ◽  
X Ray Diffraction ◽  
Ion Energy ◽  
Ion Channeling ◽  
Ion Energies ◽  
Nitrogen Ions ◽  
Nitrogen Ion

A series of molybdenum nitride films were synthesized by implanting energetic nitrogen ions into molybdenum thin films. The resulting films were characterized using x-ray diffraction to determine the effects of nitrogen ion dose (4 × 1016−4 × 1017 N+/cm2), accelerating voltage (50–200 kV), and target temperature (∼298–773 K) on their structural properties. The order of structural transformation with increased incorporation of nitrogen ions into the Mo film can be summarized as follows: Mo → γ−Mo2N → δ−MoN. Nitrogen incorporation was increased by either increasing the dose or decreasing the ion energy. At elevated target temperatures the metastable B1–MoN phase was also produced. In most cases the Mo nitride crystallites formed with the planes of highest atomic density parallel to the substrate surface. At high ion energies preferential orientation developed so that the more open crystallographic directions aligned with the ion beam direction. We tentatively attributed this behavior to ion channeling effects.

scholarly journals Mev Ion Beam Induced Index of Refraction Changes in Layered GaAs/AlGaAs Waveguides

1995 ◽  
Vol 396 ◽  
Author(s):  
T. Taylor ◽  
D. Ila ◽  
R. L. Zimmerman ◽  
P. R. Ashley ◽  
D. B. Poker
Keyword(s):  
Ion Beam ◽  
Beam Current ◽  
Electronic Energy ◽  
Index Of Refraction ◽  
Propagation Loss ◽  
Carbon Ions ◽  
Practical Applications ◽  
Oxygen Ions ◽  
Electronic Energy Transfer ◽  
Channel Waveguides

AbstractPreviously, we showed that localized optical modifications could be produced without subsequent post thermal annealing in selectively masked planar GaAs/Al 4Ga6As waveguide structures using 10 MeV oxygen ions. In our present investigation, irradiation experiments were performed on masked GaAs/Al 4Ga6As waveguide samples at 298 K using 10 MeV oxygen and 8 MeV carbon ions. The two ion incident energies were chosen to yield the maximum electronic stopping power near the interface septing the top cladding layer and the guiding layer. This localized modification process emphasizes the crucial role that the electronic energy transfer plays on the degree to which the refractive index of the guiding layer is altered. Propagation loss measurements on the fabricated channel waveguides were performed by end fire coupling a laser diode source at a wavelength of 1.3 μm. Observation of the extracted propagation loss values reveal that further optimization of the ion beam pmeters are required before practical applications can be achieved. The relative efficiency of the various ions to induce optically altered regions which serve as lateral confinement barriers of laser light shows that this fabrication process is sensitive to the ion beam current.

Up Close: The Ion Beam Materials Laboratory at Los Alamos National Laboratory

MRS Bulletin ◽  
1987 ◽  
Vol 12 (6) ◽  
pp. 101-103 ◽  
Author(s):  
J.R. Tesmer ◽  
D.M. Parkin ◽  
C.J. Maggiore
Keyword(s):  
Materials Science ◽  
Ion Beam ◽  
National Laboratory ◽  
Ion Beams ◽  
Alamos National Laboratory ◽  
Tandem Accelerator ◽  
Los Alamos ◽  
Accelerator Facility ◽  
Los Alamos National Laboratory ◽  
Research Activities

The new Ion Beam Materials Laboratory (IBML) is a Los Alamos National Laboratory (LANL) resource devoted to the characterization and modification of surfaces through the use of ion beams. IBML was developed and designed in response to a large number of recognized research needs ranging from archaeology to the Strategic Defense Initiative and from basic research to semiconductor development. Most recently, the IBML has been used in research on high temperature superconductors. The IBML was dedicated in February 1987 when the 3 MV tandem accelerator reached operational status.Beginning with an existing accelerator facility built to support nuclear physics, Los Alamos researchers added materials science capability and started to demonstrate the power of ion beam techniques as they apply to many of the Laboratory's research activities. These efforts led to a growing interest in ion beams by fellow researchers and caught the attention of LANL management. By the fall of 1984, a clear grassroots case—which was supported by the Laboratory's Center for Materials Science (CMS)—was made for developing a modern ion beam facility, which included capabilities for materials modification and analysis. The $1.7-million IBML was funded with Laboratory-wide resources in the spring of 1985 and was charged with supporting Laboratory-wide programs.

Effects of Ion Beam Milling on Surface Topography

1973 ◽  
Vol 31 ◽  
pp. 84-85
Author(s):  
P.G. Pawar ◽  
P. Duhamel ◽  
G.W. Monk
Keyword(s):  
Surface Topography ◽  
Ion Beam ◽  
Solid Material ◽  
Beam Current ◽  
Atomic Mass ◽  
Micro Milling ◽  
Ion Milling ◽  
Controlled Atmospheres ◽  
Milling Operations ◽  
Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

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