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

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.

1995 ◽  
Vol 396 ◽  
Author(s):  
Igor V. Svadkovsk ◽  
Anatoly P. Dostanko

AbstractTwo types of the ion sources for ion beam assisted deposition using inert gases, oxygen or nitrogen are reported. Their design and operational features are presented. Each of them has the properties of two existing main types of the gridless Hall sources: an end-Hall source and the anode-layer version a closed-drift ion source. Basic distinction of the developed sources is the extended range of ion energies in high-current beam for optimization of deposition, cleaning and etching processes.


1991 ◽  
Vol 235 ◽  
Author(s):  
Daniel J. Kester ◽  
Russell Messier

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.


1994 ◽  
Vol 354 ◽  
Author(s):  
H. C. Hofsäss ◽  
C. Ronntng ◽  
U. Griesmeier ◽  
M. Gross

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.


MRS Advances ◽  
2017 ◽  
Vol 2 (4) ◽  
pp. 247-252
Author(s):  
Narasimhan Srinivasan ◽  
Katrina Rook ◽  
Ivan Berry ◽  
Binyamin Rubin ◽  
Frank Cerio

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.


1991 ◽  
Vol 223 ◽  
Author(s):  
O. Vancauwenberghe ◽  
O. C. Hellman ◽  
N. Herbots ◽  
J. L. Olson ◽  
W. J. Tan ◽  
...  

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.


1992 ◽  
Vol 7 (2) ◽  
pp. 374-378 ◽  
Author(s):  
J-G. Choi ◽  
D. Choi ◽  
L.T. Thompson

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.


1997 ◽  
Vol 498 ◽  
Author(s):  
H. C. Hofsäss ◽  
M. Sebastian ◽  
H. Feldermann ◽  
R. Merk ◽  
C. Ronning

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.


1989 ◽  
Vol 157 ◽  
Author(s):  
James K. Hirvonen ◽  
T.G. Tetreault ◽  
G. Parker ◽  
P. Revesz ◽  
D. Land ◽  
...  

ABSTRACTThe ion beam assisted deposition (IBAD) technique has been employed to make aluminum oxide optical coatings. Deposition variables include aluminum oxide evaporant to oxygen ion beam flux ratios, substrate temperature, and ion energy. Characterization included optical ellipsometry, ion beam analysis, and adhesion tests. Films deposited with the aid of ions exhibited the highest refractive indices and best adhesion to their substrates.


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