The Effects of High Temperature Exposure on the Fracture of Thin Tantalum Nitride Films

1994 ◽  
Vol 343 ◽  
Author(s):  
N. R. Moody ◽  
S. K. Venkataraman ◽  
J. C Nelson ◽  
W Worobey ◽  
Andw. W. Gerberich
Keyword(s):  
Room Temperature ◽  
Tantalum Nitride ◽  
Interfacial Toughness ◽  
Sputtered Films ◽  
Sapphire Substrates ◽  
Nominal Thickness ◽  
Sputter Deposited ◽  
Temperature Exposure ◽  
Comparison Of The Results ◽  
Very High

ABSTRACTContinuous microscratch testing was used in this study to determine the effects of elevated temperature exposure on the adhesion and toughness of thin tantalum nitride films. These films were sputter-deposited at room temperature on sapphire substrates to a nominal thickness of 600 nm with some films heated to 600°C in vacuum while others were heated to 600°C in air. The films heated in vacuum exhibited no changes in composition or structure while the films heated in air completely transformed to tantalum pentoxide. Comparison of the results shows that the interfacial fracture toughness increases from 0.5 MPa-m1/2 for as-sputtered films to 0.8 MPa-m1/2 for films heated in air. However, the toughness increases to more than 3.0 MPa-m1/2 when the films are heated in vacuum. The increase in toughness values follows the reduction in deposition defect content where formation of an oxygen deficient tantalum oxide layer in air from the as-sputtered film increases interfacial toughness slightly while full densification of the tantalum nitride films in vacuum increases toughness to very high levels.

Hydrogen Effects on the Fracture of Thin Tantalum Nitride Films

1994 ◽  
Vol 356 ◽  
Author(s):  
N. R. Moody ◽  
S. K. Venkataraman ◽  
B. Bastasz ◽  
J. E. Angelo ◽  
W. W. Gerberich
Keyword(s):  
Room Temperature ◽  
Vacuum Annealing ◽  
Ion Beam ◽  
Hydrogen Ion ◽  
Tantalum Nitride ◽  
Work Of Adhesion ◽  
Sapphire Substrates ◽  
Deuterium Concentration ◽  
Sputter Deposited ◽  
Hardness Values

AbstractIn this study we used nanoindentation and continuous microscratch testing to determine the effect of hydrogen on the work of adhesion and fracture toughness of thin tantalum nitride films. These films were sputter-deposited on sapphire substrates to a thickness of 600 nm followed by the heating of some films in deuterium and some in vacuum at 300°C. Deuterium was used in this study because it is much easier to detect and measure than hydrogen. Ion beam spectroscopy showed that exposure to deuterium produced a uniform internal deuterium concentration of 2000 appm. Nanoindentation showed that exposure to deuterium at 300°C and vacuum annealing at 300°C had little effect on elastic modulus and hardness values of these films at room temperature. In contrast, the microscratch tests at room temperature revealed that the work of adhesion decreased from 24.5 J/m2 after vacuum annealing to 9.1 J/m2 after deuterium charging and demonstrated that tantalum nitride films have a strong susceptibility to hydrogen embrittlement.

Influence of Modulation Wavelength Induced Order on the Physical Properties of Nb/Rare Earth Superlattices

1984 ◽  
Vol 37 ◽  
Author(s):  
L. H. Greene ◽  
W. L. Feldmann ◽  
J. M. Rowell ◽  
B. Batlogg ◽  
R. Hull ◽  
...  
Keyword(s):  
Rare Earth ◽  
Room Temperature ◽  
Room Temperature Resistivity ◽  
Residual Resistance ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Residual Resistance Ratio ◽  
Temperature Resistivity ◽  
Modulation Wavelength

AbstractWe report the observation of a higher degree of preferred crystalline orientation in Nb/rare earth superlattices for modulation wavelengths in the range of 200 Å to 500 Å than that exhibited by single component films. All films and multilayers are sputter deposited onto room temperature sapphire substrates. Electronic transport measurements also show that the residual resistance ratio is higher and the room temperature resistivity is lower than for multilayers of either greater or lower periodicities. Transmission electron micrographs (TEM) showing excellent layering, grain size comparable to the layer thickness, and evidence of some degree of epitaxy are presented.

Sputter-Deposited Bcc Tantalum on Steel with the Interfacial Tantalum Nitride Layer

2001 ◽  
Vol 697 ◽  
Author(s):  
Anamika Patel ◽  
Leszek Gladczuk ◽  
Charanjeet Singh Paur ◽  
Marek Sosnowski
Keyword(s):  
Corrosive Wear ◽  
Beta Phase ◽  
Nitride Layer ◽  
Alpha Phase ◽  
Tantalum Nitride ◽  
Nuclear Reaction Analysis ◽  
Sputtered Films ◽  
Bcc Structure ◽  
Two Phases ◽  
Sputter Deposited

AbstractTantalum has mainly two phases: alpha phase (bcc structure) and beta phase (tetragonal structure). The meta-stable beta phase is usually obtained in sputtered films. Alpha phase is preferred over the beta for some applications as beta phase is very brittle. One of such application is to protect steel from the erosive and the corrosive wear. It was found that with the intermediate layer of tantalum nitride the preferred alpha phase was grown on steel by DC magnetron sputtering technique. Electrical and structural properties of these films were studied by four-point probe measurement and x-ray diffraction (XRD). Stoichiometry of the interfacial tantalum nitride layer was investigated by nuclear reaction analysis (NRA). Influence of the interfacial film thickness and the ratio of argon and nitrogen gas during reactive deposition of tantalum nitride on the tantalum phase were investigated. This work also reports on the dependence of tantalum phase on the substrate temperature (100-400°C) during sputtering in Ar and Kr gases.

Micro-Mechanical Characterization of Tantalum Nitride Thin Films on Sapphire Substrates

1994 ◽  
Vol 343 ◽  
Author(s):  
Shankar K. Venkataraman ◽  
John C. Nelson ◽  
Neville R. Moody ◽  
David L. Kohlstedt ◽  
William W. Gerberich
Keyword(s):  
Thin Films ◽  
Fracture Toughness ◽  
Film Thickness ◽  
Film Surface ◽  
Interfacial Fracture ◽  
Tantalum Nitride ◽  
Interfacial Fracture Toughness ◽  
Sapphire Substrates ◽  
Thin Film Resistors ◽  
Sputter Deposited

ABSTRACTThe adhesion of Ta2N thin films – often used as thin film resistors – to sapphire substrates has been studied by continuous microindentation and microscratch techniques. Ta2N films, 0.1-0.63μm in thickness, were sputter deposited onto single crystal substrates. Continuous microscratch experiments were performed by driving a conical diamond indenter simultaneously into and across the film surface until stresses high enough to delaminate the film were developed. Continuous microindentation experiments were performed to induce film spallation by normal indentation. From both of these experiments, interfacial fracture toughness was determined as a function of film thickness. The interfacial fracture toughness obtained from continuous microscratch experiments is 0.53±0.17 MPa√m, independent of film thickness. This observation indicates that there is almost no plastic deformation in the film prior to fracture so that a ‘true’ interfacial fracture toughness is measured. For the 0.63 µm thick film, continuous microindentation data yielded a fracture toughness of 0.61 ±0.08 MPa√m, which matches closely the value obtained from the microscratch test. Hence, the continuous microscratch and microindentation techniques are viable methods for determining the interfacial fracture toughness in such bi-material systems.

Stress, Microstructure and Temperature Stability of Reactive Sputter Deposited Ta(N) Thin Films

1999 ◽  
Vol 594 ◽  
Author(s):  
K. D. Leedy ◽  
M. J. O'Keefe ◽  
J. T. Grant
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Nitrogen Concentration ◽  
Temperature Stability ◽  
Microstructural Characterization ◽  
Tantalum Nitride ◽  
X Ray ◽  
Nitrogen Concentrations ◽  
Sputter Deposited ◽  
Temperature Exposure

AbstractInterest in tantalum nitride thin films for use as diffusion barriers in Cu-based microelectronic interconnects merits the study of tantalum nitride thin film properties as a function of deposition conditions and elevated temperature exposure. In this investigation, the influence of nitrogen content and post deposition annealing on the stress, microstructure and resistivity of Ta(N) films was analyzed. Ta(N) thin films were deposited by reactive dc magnetron sputtering of a Ta target in Ar/N2 gas mixtures. With an increasing N2 to Ar flow ratio, the as-deposited crystal structure of the films changed from ß-Ta to bcc Ta with N in solid solution to TaN0.1 to Ta2N and finally to TaN. The as-deposited Ta(N) stress, grain size and resistivity of the films were found to be strongly dependent on the phase(s) present. Films with less than 20 at. % nitrogen concentration displayed large compressive stress increases during 650°C anneals in flowing N2. Phase transformations to Ta2N occurred after 650°C anneals in films with nitrogen concentrations from ∼ 15 to 25 at. %. Microstructural characterization using transmission electron microscopy and x-ray diffraction, and chemical analysis by x-ray photoelectron spectroscopy and Auger electron spectroscopy of the Ta(N) films were used to identify the as-deposited and transformed phases.

Fracture of Thin Tantalum Nitride Films on Ain Substrates

1996 ◽  
Vol 436 ◽  
Author(s):  
N. R. Moody ◽  
D. Medlin ◽  
D. P. Norwood
Keyword(s):  
Tantalum Nitride ◽  
High Porosity ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Production Run ◽  
Transmission Electron ◽  
Nominal Thickness ◽  
Columnar Grains ◽  
Sputter Deposited ◽  
Film Substrate

AbstractNanoindentation, continuous nanoscratch testing, and transmission electron microscopy were used in this study to determine the structure-property relationships of thin tantalum nitride resistor films on aluminum nitride substrates. The films were sputter-deposited to a nominal thickness of 200 nm during one production run and then tested at room temperature. Most films were uniform in structure and thickness, consisting of fine equiaxed crystallites along the film-substrate interfaces and long columnar grains further away from the interface. However, one film varied greatly in thickness across the substrate. It had large crystallites along the film-substrate interface and clusters of columnar grains. Most importantly, it contained a far greater amount of porosity than the other films. The high porosity content led to significantly lower elastic moduli and hardness values than the low porosity films and a much greater susceptibility to fracture.

Characterization of rf-sputtered HfMgZnO thin films

2012 ◽  
Vol 1432 ◽  
Author(s):  
Hantsun Chung ◽  
Jian-Zhang Chen ◽  
I-Chun Cheng
Keyword(s):  
Hafnium Oxide ◽  
Short Range ◽  
Room Temperature ◽  
Visible Region ◽  
Glass Substrates ◽  
Sputtered Films ◽  
Peak Intensity ◽  
Sputter Deposited ◽  
Deposited Films

ABSTRACTMgZnO becomes amorphous or short-range-ordered with the addition of hafnium oxide. The films are rf-sputter deposited onto glass substrates (Eagle 2000, Corning Inc.) from Mg0.05HfxZn0.95-xO targets (x=0, 0.025, 0.05, 0.075, 0.1) in pure Ar ambient at room temperature. The sputtered Mg0.05Zn0.95O exhibits strong (002) preferred orientation with XRD peak located at 2θ=34.16o. The XRD peak intensity is also greatly reduced, indicating the material amorphorization proceeds with the addition of Hf. The grain size, estimated from the full-width-at-half-maximum (FWHM) of the (002) XRD peak, decreases from 24.1 to 3.3 nm as the Hf content x increases from 0 to 0.025 in Mg0.05HfxZn0.95-xO. No sharp XRD peaks are detected in the as-sputtered films when more than 5.0 at.% Hf are added into the materials. The films remain in amorphous or short-range-ordered states after annealing at 600 oC for 30 mins. All Mg0.05HfxZn0.95-xO films (100 nm in thickness) are highly transparent (> 80 %) in the visible region from 400 to 800 nm and have sharp absorption edges in the UV region. The tauc bandgap ΔE (eV), as a function of hafnium composition x, is fitted as ΔE=3.336+6.08x for room temperature as-deposited films, and ΔE=3.302+2.60x for films after 30 min 600 oC annealing. The annealing process decreases the bandgap shift caused by the incorporation of Hf in the materials.

Structural Properties of Sputter-Deposited ZnO Thin Films Depending on the Substrate Materials

2005 ◽  
Vol 475-479 ◽  
pp. 1825-1828
Author(s):  
Ju Hyun Myung ◽  
Nam Ho Kim ◽  
Hyoun Woo Kim
Keyword(s):  
Thin Films ◽  
Thermal Annealing ◽  
Room Temperature ◽  
Zno Thin Films ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
X Ray ◽  
Sapphire Substrates ◽  
Sputter Deposited

We have demonstrated the growth of ZnO thin films with c-axis orientation at room temperature on various substrates such as Si(100), SiO2, and sapphire by the r.f. magnetron sputtering method. X-ray diffraction (XRD) and scanning electron microscopy altogether indicated that the larger grain size and the higher crystallinity were attained when the ZnO films were deposited on sapphire substrates, compared to the films on Si or SiO2 substrates. The c-axis lattice constant decreased by thermal annealing for the ZnO films deposited on Si or SiO2 substrates, while increased by the thermal annealing for the ZnO films grown on sapphire substrates.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

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