Role of ion energy in determination of the sp3 fraction of ion beam deposited carbon films

ABSTRACTDirect ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.

Download Full-text

An Study of Influence of Imperfections on the Delamination of Diamond-Like Carbon Films

MRS Proceedings ◽

10.1557/proc-719-f8.36 ◽

2002 ◽

Vol 719 ◽

Author(s):

Myoung-Woon Moon ◽

Kyang-Ryel Lee ◽

Jin-Won Chung ◽

Kyu Hwan Oh

Keyword(s):

Cross Sections ◽

Focused Ion Beam ◽

Imaging System ◽

Ion Beam ◽

Carbon Films ◽

Diamond Like Carbon ◽

Glass Substrates ◽

Atomic Force ◽

Initiation And Propagation

AbstractThe role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.

Download Full-text

Large Area Surface Treatment by Ion Beam Technology

MRS Proceedings ◽

10.1557/proc-438-611 ◽

1996 ◽

Vol 438 ◽

Cited By ~ 2

Author(s):

R. L. C. Wu ◽

W. Lanter

Keyword(s):

Ion Beam ◽

High Vacuum ◽

Polycrystalline Diamond ◽

Carbon Films ◽

Ultra High Vacuum ◽

Diamond Like Carbon ◽

Chemical Compositions ◽

Rf Power ◽

Large Area ◽

Ion Energy

AbstractAn ultra high vacuum ion beam system, consisting of a 20 cm diameter Rf excilted (13.56 MHz) ion gun and a four-axis substrate scanner, has been used to modify large surfaces (up to 1000 cm2) of various materials, including; infrared windows, silicon nitride, polycrystalline diamond, 304 and 316 stainless steels, 440C and M50 steels, aluminum alloys, and polycarbonates; by depositing different chemical compositions of diamond-like carbon films. The influences of ion energy, Rf power, gas composition (H2/CH4 , Ar/CH4 and O2/CH4/H2), on the diamond-like carbon characteristics has been studied. Particular attention was focused on adhesion, environmental effects, IR(3–12 μm) transmission, coefficient of friction, and wear factors under spacelike environments of diamond-like carbon films on various substrates. A quadrupole mass spectrometer was utilized to monitor the ion beam composition for quality control and process optimization.

Download Full-text

Kinetics of ion beam nitridation (IBN) of Si and of MBE-grown Ge and SixGe1−x alloys: The role of ion energy, ion dose and substrate temperature

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/0168-583x(92)95821-8 ◽

1992 ◽

Vol 67 (1-4) ◽

pp. 301-307 ◽

Cited By ~ 18

Author(s):

O.C. Hellman ◽

N. Herbots ◽

O. Vancauwenberghe

Keyword(s):

Substrate Temperature ◽

Ion Beam ◽

Ion Energy ◽

Kinetics Of

Download Full-text

Direct ion beam deposition of carbon films on silicon in the ion energy range of 15–500 eV

Journal of Applied Physics ◽

10.1063/1.350177 ◽

1991 ◽

Vol 70 (10) ◽

pp. 5623-5628 ◽

Cited By ~ 40

Author(s):

W. M. Lau ◽

I. Bello ◽

X. Feng ◽

L. J. Huang ◽

Qin Fuguang ◽

...

Keyword(s):

Energy Range ◽

Ion Beam ◽

Carbon Films ◽

Ion Energy ◽

Ion Beam Deposition ◽

Beam Deposition

Download Full-text

Surface and Bulk Microstructural Modifications in Amorphous Carbon Films after Post-Growth Low Energy Ion Beam Irradiation

MRS Proceedings ◽

10.1557/proc-650-r3.42 ◽

2000 ◽

Vol 650 ◽

Author(s):

P. Patsalas ◽

S. Logothetidis

Keyword(s):

Amorphous Carbon ◽

Amorphous Matrix ◽

Ion Beam ◽

Carbon Films ◽

Low Energy ◽

Beam Irradiation ◽

X Ray Diffraction ◽

Ion Beam Irradiation ◽

Ion Energy ◽

X Ray

ABSTRACTWe present the crystallization effects occurring in sputtered amorphous Carbon (a-C) thin films deposited on Si induced by post-growth low energy (0.5-1.5 keV) Ar+ ion beam irradiation (IBI). The a-C films after IBI have the form of an amorphous matrix with embedded crystalline regions. X-ray diffraction and Electron Microscopy measurements identified the crystalline phases of carbon and SiC. We study in detail the effects of ion energy and fluence on the crystallization process. It was found that low fluence (∼2×1016 ions/cm2) of ions with an optimum ion energy (∼1.5 keV) promoted the diamond formation. X-Ray Reflectivity (XRR) and Spectroscopic Ellipsometry were used to study the amorphous matrix. XRR discriminated the IBI induced surface and bulk effects through the density and the a-C surface roughness, showing surface smoothing to be more prominent for low energy IBI.

Download Full-text

Elastic Properties of Diamond-Like Amorphous Carbon Films Grown by Computer Simulation of Ion-Beam Deposition Process

MRS Proceedings ◽

10.1557/proc-648-p6.53 ◽

2000 ◽

Vol 648 ◽

Cited By ~ 1

Author(s):

A.Yu. Belov ◽

H.U. Jäger

Keyword(s):

Amorphous Carbon ◽

Elastic Constants ◽

Ion Beam ◽

Carbon Films ◽

Atomic Scale ◽

Ion Energy ◽

Amorphous Carbon Films ◽

Ion Beam Deposition ◽

Bulk Stress ◽

Beam Deposition

AbstractAtomic-scale calculations were performed for the first time to investigate mechanical properties of amorphous carbon films grown by a realistic simulation of ion-beam deposition. The simulated films have a thickness of a few nanometers and reproduce the main structural features of real films, with the bulk content of sp3 bonded atoms varying from 35 to 95%, depending on the ion energy (E = 20-80 eV). Employing empirical interatomic potentials for carbon, the average bulk stresses as well as the atomic-level stress distributions were calculated and analysed. The bulk stresses were found to depend not only on the ion energy, but also on the film quality, in particular, on such structural inhomogeneities as local fluctuations of the sp3 fraction with the depth. The local variation of the bulk stress from the average value considerably increases as the local content of sp2 bonded atoms increases. Elastic constants of amorphous carbon films were also computed using the method of inner elastic constants, which allows for the stress dependence of elastic constants to be analysed. The variation of Young's modulus as a function of the lateral bulk stress in an amorphous film is demonstrated.

Download Full-text

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

MRS Advances ◽

10.1557/adv.2017.23 ◽

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.

Download Full-text

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

MRS Proceedings ◽

10.1557/proc-223-235 ◽

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.

Download Full-text