Residual Stress Control by Ion Beam Assisted Deposition

1995 ◽  
Vol 396 ◽  
Author(s):  
G. S. Was ◽  
J. W. Jones ◽  
L. Parfitt ◽  
C.E. Kalnas ◽  
M. Goldiner
Keyword(s):  
Residual Stress ◽  
Functional Dependence ◽  
Ion Beam ◽  
Arrival Rate ◽  
Gas Content ◽  
Metallic Films ◽  
Amorphous Films ◽  
Tensile Direction ◽  
Ion Beam Assisted Deposition ◽  
Wide Range

AbstractThe origin of residual stresses were studied in both crystalline metallic films and amorphous oxide films made by ion beam assisted deposition (IBAD). Monolithic films of AI2O3 were deposited during bombardment by Ne, Ar or Kr over a narrow range of energies, E, and a wide range of ion-to-atom arrival rate ratios, R and were characterized in terms of composition, thickness, density, crystallinity, microstructure and residual stress. The stress was a strong function of ion beam parameters and gas content and compares to the behavior of other amorphous compounds such as MoSix and WS12.2 With increasing normalized energy (eV/atom), residual stress in crystalline metallic films (Mo, W) increases in the tensile direction before reversing and becoming compressive at high normalized energy. The origin of the stress is most likely due to densification or interstitial generation. Residual stress in amorphous films (Al2O3, MoSix and WSi2.2) is initially tensile and monotonically decreases into the compressive region with increasing normalized energy. The amorphous films also incorporate substantially more gas than crystalline films and in the case of Al2O3 are characterized by a high density of voids. Stress due to gas pressure in existing voids explains neither the functional dependence on gas content nor the magnitude of the observed stress. A more likely explanation for the behavior of stress is gas incorporation into the matrix, where the amount of incorporated gas is controlled by trapping.

Microstructure and Residual Stresses in Al2O3 Prepared by Ion Beam Assisted Deposition

1993 ◽  
Vol 316 ◽  
Author(s):  
M. G. Goldiner ◽  
G. S. Was ◽  
L. J. Parfitt ◽  
J. W. Jones
Keyword(s):  
Residual Stress ◽  
Ion Beam ◽  
Arrival Rate ◽  
Film Stress ◽  
Amorphous Phases ◽  
Alumina Films ◽  
Compressive Stresses ◽  
Ion Beam Assisted Deposition ◽  
Rapid Transition ◽  
Film Porosity

ABSTRACTAlumina films synthesized by ion beam assisted deposition (EBAD) were characterized in terms of their microstructure and residual stress. Normalized energy per deposited atom, En, ranged from 0 to 130 eV/atom. The microstructure of PVD films (En=0) is a mixture of crystalline (γ-Al2O3) and amorphous phases and IBAD films are amorphous. Density and stoichiometry vary between 2.6 and 3.1 g/cm3 and 1.3 and 1.6, respectively. Neither are dependent on either ion-to-atom arrival rate ratio, R, or En. The film porosity is in the form of small (4-6 nm) voids of density 1017 - 1018 cm-3. Bombarding gas is incorporated with 80% efficiency to levels of 4-5 at. %. A tensile residual stress of 0.3 GPa exists in PVD films. A rapid transition to high compressive stresses occurs with increased En, with a saturation of -0.4 GPa occurring at high En There is a strong correlation between gas incorporation and residual film stress. However, no existing models are capable of providing a quantitative explanation of the results.

Synthesis and Mechanical Properties of Niobium Films by Ion Beam Assisted Deposition

1996 ◽  
Vol 434 ◽  
Author(s):  
H. Ji ◽  
G. S. Was ◽  
J. W. Jones
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Physical Vapor Deposition ◽  
Incident Angle ◽  
Ion Beam ◽  
Arrival Rate ◽  
Fiber Texture ◽  
Ion Energy ◽  
Ion Beam Assisted Deposition ◽  
R Ratio

AbstractMechanical properties of niobium thin films are studied by controlling the microstructure, texture and residual stress of the films using ion beam assisted deposition (IBAD). Niobium films were deposited onto (100) Si substrates and their microstructure, texture and residual stress were measured as a function of ion energy and R ratio (ion to atom arrival rate ratio). The grain sizes of these films ranged from 20 nm to 40 nm and no effect of ion bombardment was observed. All the films have strong (110) fiber texture, but the in-plane texture is a strong function of the incident angle, energy and flux of the ion beam. Results show that while the degree of the texture increases with increasing ion energy and flux, it is also a strong linear function of the product of the two. The residual stress of the films was measured by a scanninglaser reflection technique. As a function of normalized energy, the stress is tensile for En < 30 eV/atom with a maximum of 400 MPa at about 15 eV/atom. It becomes compressive with increasing normalized energy and saturates at - 400 MPa for En > 50 eV/atom. Both PVD (physical vapor deposition) and IBAD films have a hardness of about 6 GPa at shallow depth measured by nanoindentation. The different stress state may be responsible for the 15%difference on hardness observed between the PVD and IBAD films.

Mechanical Properties and Residual Stresses in Oxide/Metal Multilayer Films Synthesized by Ion Beam Assisted Deposition

1993 ◽  
Vol 308 ◽  
Author(s):  
C. E. Kalnas ◽  
L. J. Parfitt ◽  
M. G. Goldiner ◽  
G. S. Was ◽  
J. W. Jones
Keyword(s):  
Residual Stress ◽  
Critical Strain ◽  
Ion Beam ◽  
Crack Density ◽  
Multilayer Films ◽  
Compressive Stresses ◽  
Ion Beam Assisted Deposition ◽  
Small Grains ◽  
Ductile Substrates ◽  
Metal Layers

ABSTRACTFilms of Al, Al2O3 and Al/Al2O3 microlaminates were formed by ion beam assisted deposition (IBAD) at R ratios from 0.0025 to 0.5 and film thicknesses between 150 and 2600 nm. Oxide films were amorphous while metal layers were crystalline with small grains and texture for both PVD and IBAD conditions. The average stress in the oxide film is tensile at R=0 and becomes compressive, saturating at approximately 15 eV/atom. The residual stress in the Al films is tensile over all R ratios and the stress in the microlaminate roughly follows a rule of mixtures. Deformation of ductile substrates on which films had been deposited revealed that the critical strain to fracture was strongly dependent on residual stress. Large compressive stresses in monolithic films produced by ion beam assisted deposition delayed the onset of crack initiation while the presence of multiple layers, in general, lowered the crack density at saturation, suggesting a possible ductilizing effect.

Composition and Phase Control for Molybdenum Nitride thin Films

1994 ◽  
Vol 354 ◽  
Author(s):  
Mandar S. Mudholkar ◽  
Levi T. Thompson
Keyword(s):  
Thin Films ◽  
Energy Density ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Arrival Rate ◽  
Molybdenum Nitride ◽  
Effective Energy ◽  
Film Composition ◽  
Ion Beam Assisted Deposition ◽  
Molybdenum Nitrides

AbstractMolybdenum nitrides are active and selective hydrodenitrogenation (HDN) catalysts. The catalytic properties of molybdenum nitrides were found to be dependent on the structural properties. The purpose of research described in this paper was to synthesize molybdenum nitride thin films with well defined structures and stoichiometries using ion beam assisted deposition. The films were deposited by evaporating Mo metal, and simultaneously bombarding the growing film with low energy nitrogen ions. The phase constituents of the films were determined using x-ray diffraction and the film composition was obtained by Rutherford backscattering spectrometry.The film composition and phase constituents were strong functions of the ion-to-atom arrival rate ratio, ion energy and ion angle of incidence. Differences in the film composition for different arrival rate ratios and ion angles of incidence were interpreted based on reflection and sputtering effects. Our results suggest that phase formation was governed by the effective energy density per deposited atom. Evaluation of the effective energy density per deposited atom and its physical significance in ion beam assisted deposition is discussed.

Properties of metallic films on polymer substrates coated by Ar+ ion-beam-assisted deposition

1994 ◽  
Vol 66 (1-3) ◽  
pp. 509-513 ◽  
Author(s):  
Ichiro Takano ◽  
Noriyuki Inoue ◽  
Kazuaki Matsui ◽  
Shintaro Kokubu ◽  
Masato Sasase ◽  
...  
Keyword(s):  
Ion Beam ◽  
Metallic Films ◽  
Polymer Substrates ◽  
Ion Beam Assisted Deposition

Mechanical properties and residual stress in AlN films prepared by ion beam assisted deposition

2000 ◽  
Vol 18 (4) ◽  
pp. 1567-1570 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Nobuaki Kitazawa ◽  
Yoshikazu Nakamura ◽  
Chunliang Li ◽  
Tohru Sekino ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Ion Beam ◽  
Ion Beam Assisted Deposition

Surface Morphology of Nb Films by Ion Beam Assisted Deposition

1996 ◽  
Vol 440 ◽  
Author(s):  
Hong Ji ◽  
Gary S. Was ◽  
J. Wayne ◽  
Neville R. Moody
Keyword(s):  
Surface Morphology ◽  
Film Thickness ◽  
Rate Ratio ◽  
Ion Beam ◽  
Arrival Rate ◽  
Mean Square ◽  
Sapphire Substrates ◽  
Ion Beam Assisted Deposition ◽  
Ion Energies ◽  
Beam Incident

AbstractNiobium films of thickness 50 nm to 1000 nm were deposited by ion beam assisted deposition (IBAD) using ion energies of 0, 500 and 1000 eV, and R ratios (ion-to-atom arrival rate ratio) of 0, 0.1, and 0.4 on (100) silicon and (0001) sapphire substrates. The films have columnar structures and the column width increases with normalized energy (En = E × R). The surface morphology depends on both the normalized energy of the ion beam, En, and the film thickness. All films have dome-like surface features that are oriented along the ion beam incident direction. The dimension of these features increases with normalized energy and film thickness. Surface roughness also increases with normalized energy and film thickness, with the root mean square (rms) roughness increasing from 1.6 nm for the PVD sample (100 nm thick) to 36.7 nm for the IBAD film (1000 eV, R = 0.4, 800 nm thick). The surface morphology of IBAD films is the result of a combination of channeling and shadowing effects.

Composition and Structure of Zirconium Nitride Films Produced by Ion Assisted Deposition

1994 ◽  
Vol 354 ◽  
Author(s):  
R. Valizadeh ◽  
J.S. Colligon ◽  
S.E. Donnelly ◽  
C.A. Faunce ◽  
D. Park ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Ion Beam ◽  
Arrival Rate ◽  
Zirconium Nitride ◽  
Ion Beam Sputtering ◽  
Tem Analysis ◽  
Grain Sizes ◽  
Composition And Structure ◽  
Wide Range ◽  
Beam Sputtering

AbstractThe growth mechanism of ZrNx films produced by reactive ion beam sputtering with or without concurrent low energy ion bombardment of argon or nitrogen has been investigated. The effect of substrate temperature in the range of 300-680K, partial pressure of nitrogen and ion/atom arrival rate on the composition and microstructure of the films have been studied. RBS analysis has confirmed that the nitrogen content varies over wide range 0-60 at. %, depending on the nitrogen/zirconium arrival rate, and the ion assist flux but it is independent of the ion assist energy. TEM analysis shows that the films are non-columnar and polycrystalline with grain sizes l-15nm which depend on the nitrogen content and the deposition temperature.

Mechanical Properties of AlN Thin Films Prepared by Ion Beam Assisted Deposition

2000 ◽  
Vol 647 ◽  
Author(s):  
Shuichi Miyabe ◽  
Toshiyuki Okawa ◽  
Nobuaki Kitazawa ◽  
Yoshihisa Watanabe ◽  
Yoshikazu Nakamura
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Residual Stress ◽  
Beam Energy ◽  
Ion Beam ◽  
High Energy ◽  
Columnar Structure ◽  
Ion Beam Assisted Deposition ◽  
Film Hardness ◽  
Nitrogen Ion

AbstractAluminum nitride (AlN) thin films were prepared by ion-beam assisted deposition method, and the influence of the nitrogen ion beam energy on their microstructure and mechanical properties was studied by changing the ion beam energy from 0.1 to 1.5 keV. Films prepared with a low-energy ion beam show a columnar structure, while films prepared with a high-energy ion beam show a granular structure. The film hardness is found to decrease with increasing nitrogen ion beam energy. It is also found that the film hardness does not change drastically after annealing in nitrogen atmosphere at 500 °C, yielding the residual stress relaxation. It is proposed that the film hardness is dependent on the film microstructure, which can be controlled with the nitrogen ion beam energy, rather than the residual stress in the films.

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