Modeling of the Ion-Beam Growth of Covalently-Bonded Diamondlike Materials

1997 ◽  
Vol 498 ◽  
Author(s):  
H. C. Hofsäss ◽  
M. Sebastian ◽  
H. Feldermann ◽  
R. Merk ◽  
C. Ronning
Keyword(s):  
Film Growth ◽  
Ion Beam ◽  
Cubic Boron Nitride ◽  
Film Structure ◽  
Ion Energy ◽  
Covalently Bonded ◽  
Ion Energies ◽  
Ion Impact ◽  
Impact Events ◽  
Dissipation Processes

ABSTRACTA characteristic ion energy and substrate temperature dependence for the formation of tetra-hedral amorphous carbon (ta-C), cubic boron nitride (c-BN) and related diamondlike materials by ion deposition has been experimentally observed. We present an analytical model for diamondlike film growth that describes the transient modification of the film structure by successive individual ion impact events. Each ion impact is treated as a cylindrical thermal spike with a finite initial width, taking into account energy loss and energy dissipation processes. We show that rearrangement of atoms during a cylindrical spike is the dominant mechanism leading to the formation of the diamondlike phase. The model explains quantitatively the observed ion energy dependence of the sp3 bond fraction in ta-C, as well as the broad range of ion energies for which c-BN growth is observed.

Ion Beam Assisted Deposition of Cubic Boron Nitride Thin Films

1991 ◽  
Vol 235 ◽  
Author(s):  
Daniel J. Kester ◽  
Russell Messier
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Boron Nitride ◽  
Ion Beam ◽  
Cubic Boron Nitride ◽  
Secondary Phase ◽  
Ion Energy ◽  
Ion Beam Assisted Deposition ◽  
Transmission Electron ◽  
Argon Ions

ABSTRACTBoron nitride thin films were grown using ion beam assisted deposition. Boron metal was evaporated, and the depositing film was bombarded by nitrogen and argon ions. The films were characterized using Fourier transform infrared spectroscopy, electron diffraction, transmission electron microscopy, and Rutherford backscattering. The thin films were found to be cubic boron nitride, consisting of 100–200 Å crystallites with a small amount of an amorphous secondary phase. The best conditions for depositing cubic boron nitride were found to be a substrate temperature of 400°C, bombardment by a 50:50 mixture of argon and nitrogen with a bombarding ion energy of 500 eV and a ratio of bombarding ions to depositing boron atoms of from 1.0 to 1.5 ions per atom.

The Effects of Ion Energy on Carbon and Tungsten Films Fabricated by Direct Ion Beam Deposition and Ion Beam Sputtering Deposition

1991 ◽  
Vol 223 ◽  
Author(s):  
I. Kataoka ◽  
K. Ito ◽  
N. Hoshi ◽  
T. Yonemitsu ◽  
K. Etoh ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ion Beam ◽  
Amorphous Structure ◽  
Film Structure ◽  
Ion Beam Sputtering ◽  
Ion Energy ◽  
Sputtering Deposition ◽  
Ion Beam Deposition ◽  
Beam Sputtering ◽  
Beam Deposition

ABSTRACTThe x-ray reflectivity and surface morphology of C/W multilayers fabricated by ion beam sputtering (IBS) method was evaluated. Also the surface roughness and amorphous structure of C and W films fabricated by direct ion beam deposition (DIBD) method were evaluated as a function of ion energy. The reflectivity was measured by the C-K line (4.47nm) and STM was used for surface roughness measurement and root-mean-square value of correlation function of the RHEED pattern was used for evaluation of amorphous structure. The reflectivity of C/W multilayer was about 69% of the theoretical one, and micro-columnar structures were observed from STM images. The film structure and surface roughness of DIBD film were changed with the depositing ion energy. The surface roughness of films becomes smaller as the depositing energy becomes higher in the energy range from 20 to 140eV.

1X Thin Films Prepared By Mass Separated Ion Beam Deposition

1994 ◽  
Vol 354 ◽  
Author(s):  
H. C. Hofsäss ◽  
C. Ronntng ◽  
U. Griesmeier ◽  
M. Gross
Keyword(s):  
Thermal Activation ◽  
Room Temperature ◽  
Ion Beam ◽  
Ir Absorption ◽  
Ion Energy ◽  
Ion Beam Deposition ◽  
Ion Energies ◽  
Substrate Temperatures ◽  
Absorption Measurements ◽  
Beam Deposition

AbstractWe have studied the growth and the properties of CN films prepared by deposition of mass separated 12C+ and 14N+ ions. The film thickness and density were determined as a function of ion energy between 20 eV and 500 eV and for substrate temperatures of 20 °C and 350 °C. Sputtering effects limit the maximum N concentration to about 30 - 40 at.% even for ion energies as low as 20 eV. IR absorption measurements indicate predominantly C-N and C=N bonding and an amorphous or strongly disordered CN-network. For room temperature deposited CN films with N concentrations up to 25 at.% I-V curves of metal-CN-metal devices show Frenkel-Poole behavior due to field-enhanced thermal activation of localized electrons. Films deposited at 350 °C have N concentrations below 15 at.% and graphitic properties like low resistivity and a density close to graphite.

Ion Beam Etch for Patterning of Resistive RAM (ReRAM) Devices

MRS Advances ◽  
2017 ◽  
Vol 2 (4) ◽  
pp. 247-252
Author(s):  
Narasimhan Srinivasan ◽  
Katrina Rook ◽  
Ivan Berry ◽  
Binyamin Rubin ◽  
Frank Cerio
Keyword(s):  
Beam Energy ◽  
Etch Rate ◽  
Incidence Angle ◽  
Ion Beam ◽  
Ion Energy ◽  
Beam Voltage ◽  
Ion Energies ◽  
Sidewall Angle ◽  
Etch Rates

ABSTRACTWe investigate the feasibility of inert ion beam etch (IBE) for subtractive patterning of ReRAM-type structures. We report on the role of the angle-dependent ion beam etch rates in device area control and the minimization of sidewall re-deposition. The etch rates of key ReRAM materials are presented versus incidence angle and ion beam energy. As the ion beam voltage is increased, we demonstrate a significant enhancement in the relative etch rate at glancing incidence (for example, by a factor of 2 for HfO2). Since the feature sidewall is typically exposed to glancing incidence, this energy-dependence plays a role in optimization of the feature shape and in sidewall re-deposition removal.We present results of SRIM simulations to estimate depth of ion-bombardment damage to the TMO sidewall. Damage is minimized by minimizing ion energy; its depth can be reduced by roughly a factor of 5 over typical IBE energy ranges. For example, ion energies of less than ∼250 eV are indicated to maintain damage below ∼1nm. Multi-angle and multi-energy etch schemes are proposed to maximize sidewall angle and minimize damage, while eliminating re-deposition across the TMO. We utilize 2-D geometry/3-D etch model to simulate IBE patterning of tight-pitched ReRAM features, and generate etched feature shapes.

The Importance of Self-Sputtering by Low Energy Ions in Partially Ionized Beam Deposition

1989 ◽  
Vol 157 ◽  
Author(s):  
P. Bai ◽  
CH. SteinbrÜChel ◽  
T.-M. Lu
Keyword(s):  
Film Growth ◽  
Ion Beam ◽  
Threshold Energy ◽  
The Self ◽  
Ion Energy ◽  
Sputtering Yield ◽  
Partially Ionized ◽  
Low Energy Ions ◽  
Deposition Techniques ◽  
Beam Deposition

ABSTRACTIn ion-assisted deposition techniques such as partially ionized beam deposition, ions derived from the depositing material itself concurrently bombard the surface during thin film growth. The ion percentage in the deposition beam ranges from less than 0.1% to 100% (Ion Beam Deposition) with the ion energy varying between a few eV and several keV. When the sputtering yield of the self-sputtering is greater than one, there is a critical ion percentage, for a given ion energy, above which no net deposition can be obtained. The self-sputtering yield is shown to have a square root dependence on the ion energy above the threshold energy by fitting the experimental data obtained from the literature. The critical ion percentage for Al, Cu, Au, Ag, and C is then calculated and plotted as a function of the ion energy so that deposition and no-deposition regions are illustrated in terms of the ion energy and ion percentage.

Room Temperature Nitridation and Oxidation of Si, Ge and Mbegrown Sige Using Low Energy Ion Beams (0.1-1 Kev).

1991 ◽  
Vol 223 ◽  
Author(s):  
O. Vancauwenberghe ◽  
O. C. Hellman ◽  
N. Herbots ◽  
J. L. Olson ◽  
W. J. Tan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Film Properties ◽  
Dielectric Thin Films ◽  
Ion Energy ◽  
Insulating Films ◽  
Ion Energies ◽  
Energy Dependent

ABSTRACTDirect Ion Beam Nitridation (IBN) and Oxidation (IBO) of Si, Ge, and Si0.8Ge0.2 were investigated at room temperature as a function of ion energy. The ion energies were selected between 100 eV and 1 keV to establish the role of energy on phase formation and film properties. Si0.8Ge0.2 films were grown by MBE on Si (100) and transferred in UHV to the ion beam processing chamber. The modification of composition and chemical binding was measured as a function of ion beam exposure by in situ XPS analysis. The samples were nitridized or oxidized using until the N or O 1s signal reached saturation for ion doses between 5×1016 to 1×1017 ions/cm2. Combined characterization by XPS, SEM, ellipsometry and cross-section TEM showed that insulating films of stoichiometric SiO2 and Si-rich Si3N4 were formed during IBO and IBN of Si at all energies used. The formation of Ge dielectric thin films by IBO and IBN was found to be strongly energy dependent and insulating layers could be grown only at the lower energies (E ≤ 200 eV). In contrast to pure Ge, insulating SiGe-oxide and SiGe-nitride were successfully formed on Si0.8Ge0.20.2 at all energies studied.

Defect production during ion-assisted deposition of molybdenum films studied by molecular dynamics

1997 ◽  
Vol 504 ◽  
Author(s):  
Peter Klaver ◽  
Barend Thijsse
Keyword(s):  
Molecular Dynamics ◽  
Physical Vapor Deposition ◽  
Film Growth ◽  
Ion Beam ◽  
Defect Production ◽  
Deposition Surface ◽  
Ion Beam Assisted Deposition ◽  
Ion Impact ◽  
Dynamics Simulations ◽  
Argon Ion

ABSTRACTLow energy argon-ion assisted growth of thin molybdenum films (∼ 60 Å) has been studied by molecular dynamics simulations. The effects of a single ion impact are discussed, but more particularly we consider film growth from a manufacturing viewpoint and examine the properties of the completed films. Results for ion-beam assisted deposition are compared with those for unassisted growth (i.e. physical vapor deposition). Surface morphology, defect generation, argon incorporation, and the various responsible atomic mechanisms are discussed.

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.

Microstructure of c-BN Films Deposited by IBAD: IR and Hrem Analyses

1997 ◽  
Vol 472 ◽  
Author(s):  
S. Ilias ◽  
J. Pascallon ◽  
V. Stambouli ◽  
D. Bouchier ◽  
G. Nouet
Keyword(s):  
Depth Distribution ◽  
Ion Beam ◽  
Interfacial Zone ◽  
Ion Energy ◽  
Ion Beam Assisted Deposition ◽  
Phase Concentration ◽  
Ion Energies ◽  
Ir Transmission ◽  
Transmission Measurements

ABSTRACTThe in-depth distribution of phases in c-BN films deposited by Ion Beam Assisted Deposition (IBAD) at two different ion energy values (300 and 600 eV) was investigated using the quantitative IR transmission measurements and the HREM technique. Whatever the value of the studied ion energies, the characteristic layered morphology of c-BN film is observed including the interfacial sp2 zone between the substrate and the c-BN volume. In the case of 600 eV ion energy, this interfacial zone is less well-defined in comparison with 300 eV ion energy and the corresponding thickness is more important. Furthermore, the h-BN phase is more diluted within the c-BN film volume showing that the purest phase concentration of c-BN is found for the lowest ion energy, i.e. 300 eV.

Room Temperature Growth of Silicon Dioxide Using a Low Energy Ion Beam

1986 ◽  
Vol 75 ◽  
Author(s):  
S. S. Todorov ◽  
E. R. Fossum
Keyword(s):  
Silicon Dioxide ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Film Growth ◽  
Ion Beam ◽  
Silicon Surfaces ◽  
Ion Energy ◽  
Thermally Driven ◽  
Thin Oxide Films ◽  
Substrate Temperatures

AbstractUltra-thin films of silicon dioxide are formed on silicon surfaces at room temperature by direct bombardment with an oxygen-containing ion beam at energies of 150 eV or less. The process of film growth is studied.through ellipsometric measurements of their properties as a function of ion energy and dose, oxygen partial pressure and substrate temperature. Typical oxide thicknesses of the order of 50 Å are obtained by three minute or longer exposures to beams of current density 135 μA/cm2. Ion-beam grown oxides are compared to conventional thin oxide films grown at elevated temperatures and show the same stoichiometry. The growth rate decreases rapidly after a continuous oxide film has been formed. Performing the ion bombardment at elevated substrate temperatures leads to only small enhancement of the oxide growth indicating non-thermally driven reaction kinetics.

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