Characteristics of tin whiskers formed on sputter-deposited films—an aging study

2004 ◽  
Vol 19 (3) ◽  
pp. 689-692 ◽  
Author(s):  
J.P. Winterstein ◽  
J.B. LeBret ◽  
M.G. Norton

Tin whiskers formed on sputter-deposited films on Muntz metal substrates have been examined following long-term aging at room temperature. It was found that while the initial annealing conditions determined the original nucleation and growth rates, whisker nucleation and growth was a continuous process and appeared to be occurring throughout the duration of the study. Whisker densities increased for all samples during aging, and samples that initially showed no whiskers during high-temperature annealing had a population density of 2.5 mm−2 after storage for 15 months.

1997 ◽  
Vol 493 ◽  
Author(s):  
Adriaan C. Carter ◽  
James S. Horwitz ◽  
Douglas B. Chrisey ◽  
Jeffrey M. Pond ◽  
Steven W. Kirchoefer ◽  
...  

ABSTRACTSingle phase, (100) oriented Ba0.5Sr0.5TiO3 films have been deposited by pulsed laser deposition onto (100) LaAIO3, SrTiO3, MgO substrates. The dielectric properties of these films were measured using interdigitated capacitors as a function of DC bias and temperature at 1 MHz and as a function of DC bias at 1 to 20 GHz at room temperature. Deposited films were annealed over a temperature range of 900 to 1350 C for 1 to 8 hours to observe its effect on dielectric properties. Chemical analysis on films deposited from stoichiometric targets showed the films to be up to 6% deficient in Ba and Sr under typical PLD deposition conditions. Optimal annealing conditions and target stoichiometries for minimizing dielectric loss and maximizing tuning are discussed.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1320 ◽  
Author(s):  
Mohamed Abdel-Rahman ◽  
Muhammad Zia ◽  
Mohammad Alduraibi

In this study, vanadium oxide (VxOy) semiconducting resistive thermometer thin films were developed, and their temperature-dependent resistive behavior was examined. Multilayers of 5-nm-thick vanadium pentoxide (V2O5) and 5-nm-thick vanadium (V) films were alternately sputter-deposited, at room temperature, to form 105-nm-thick VxOy films, which were post-deposition annealed at 300 °C in O2 and N2 atmospheres for 30 and 40 min. The synthesized VxOy thin films were then patterned into resistive thermometer structures, and their resistance versus temperature (R-T) characteristics were measured. Samples annealed in O2 achieved temperature coefficients of resistance (TCRs) of −3.0036 and −2.4964%/K at resistivity values of 0.01477 and 0.00819 Ω·cm, respectively. Samples annealed in N2 achieved TCRs of −3.18 and −1.1181%/K at resistivity values of 0.04718 and 0.002527 Ω·cm, respectively. The developed thermometer thin films had TCR/resistivity properties suitable for microbolometer and antenna-coupled microbolometer applications. The employed multilayer synthesis technique was shown to be effective in tuning the TCR/resistivity properties of the thin films by varying the annealing conditions.


1997 ◽  
Vol 505 ◽  
Author(s):  
N. R. Moody ◽  
D. Medlin ◽  
D. Boehme ◽  
D. Norwood

ABSTRACTIn this study, nanoindentation and nanoscratch testing were used to determine the effects of annealing and long term aging on the properties and fracture resistance of thin tantalum nitride resistor films on aluminum nitride substrates. These films were sputter-deposited to a thickness of 440 nm. Some films were left in the as-deposited condition while others were annealed or annealed and then aged. X-ray diffraction revealed that sputter deposition created high compressive residual stresses in the as-deposited films which were partially relieved by annealing. Subsequent aging of the annealed films had no effect on residual stress levels. Nanoindentation showed that mechanical properties were unchanged after annealing and after annealing and aging. However, nanoscratch testing showed that annealing markedly reduced the susceptibility to catastrophic failure with no further changes discernible after aging.


2005 ◽  
Vol 905 ◽  
Author(s):  
Elamurugu Elangovan ◽  
Antonio Marques ◽  
Ana Pimentel ◽  
Rodrigo Martins ◽  
Elvira Fortunato

AbstractMolybdenum doped indium oxide (IMO) thin films rf sputtered at room temperature were studied as a function of oxygen volume percentage (O2 vol. %) varied between 0 and 17.5. The as-deposited films were amorphous irrespective of O2 vol. %. The minimum transmittance (<10 %) of the films deposited without oxygen has been increased on introducing oxygen (3.5 O2 vol. %) to a maximum of 90 %. The optical band gap has been increased from 3.80 eV (without oxygen) to 3.92 eV (3.5 O2 vol. %). The films were highly resistive and the hall coefficients were detectable only for the films deposited without oxygen. In order to increase the electrical conductivity, the films were annealed in the range 100-500°C in open-air and N2/H2 gas for 1 hour. The annealed films become polycrystalline with enhanced electrical and optical properties. The effect of annealing conditions on these films will be presented and discussed in detail.


2004 ◽  
Vol 854 ◽  
Author(s):  
Christophe Malhaire ◽  
Alexandru Andrei ◽  
Sebastiano Brida ◽  
Daniel Barbier

ABSTRACTThe purpose of the present work was to study the long term stress stability of thin films used in harsh environment sensors. A stress determination method, based on cantilevers curvatures measurements, checked by means of 3D finite element simulations, has been proposed. Stress measurements for dielectric (silicon oxide and nitride) and metallic (AlTi and TiW) thin films have been periodically performed at room temperature, after standard annealing (450°C / 30 min in a N2+H2 atmosphere) and after 4 weeks thermal aging at 150°C or 200°C.


2012 ◽  
Vol 1432 ◽  
Author(s):  
Hantsun Chung ◽  
Jian-Zhang Chen ◽  
I-Chun Cheng

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.


1987 ◽  
Vol 92 ◽  
Author(s):  
T. Brat ◽  
J.C.S. Wei ◽  
J. Poole ◽  
D. Hodul ◽  
N. Parikh ◽  
...  

ABSTRACTWe have investigated the formation of titanium silicide films sputter deposited from a high purity (99.995%) composite TiSi2.2 target. The films, sputtered at a rate of 3.7 nm/sec, were deposited on Si(100), Si02 , and N+ Poly-Si substrates at temperatures ranging from room temperature to 425°C. Room temperature depositions produced amorphous films, while heated substrate depositions formed crystalline films with a metastable C49 TiSi2 structure. Rapid thermal processing of these films at temperatures higher than 700°C resulted in the formation of a stable C54 TiSi2 structure. Stoichiometry of the deposited films over a 10 cm diameter wafer was found to be independent of the substrate temperature. Stress in the films was measured as a function of deposition and annealing parameters. The amorphous films showed a tensile stress of about 0.1 GPa, while films deposited on substrates at 425°C had an order of magnitude higher tensile stress level.The resistivity measured on the 400°C deposited films was about half of that obtained with the films deposited at roomtemperature. A comparison between films deposited on a hot substrate and those which were rapid thermal processed is presented.


Author(s):  
G. M. Michal ◽  
T. K. Glasgow ◽  
T. J. Moore

Large additions of B to Fe-Ni alloys can lead to the formation of an amorphous structure, if the alloy is rapidly cooled from the liquid state to room temperature. Isothermal aging of such structures at elevated temperatures causes crystallization to occur. Commonly such crystallization pro ceeds by the nucleation and growth of spherulites which are spherical crystalline bodies of radiating crystal fibers. Spherulite features were found in the present study in a rapidly solidified alloy that was fully crysstalline as-cast. This alloy was part of a program to develop an austenitic steel for elevated temperature applications by strengthening it with TiB2. The alloy contained a relatively large percentage of B, not to induce an amorphous structure, but only as a consequence of trying to obtain a large volume fracture of TiB2 in the completely processed alloy. The observation of spherulitic features in this alloy is described herein. Utilization of the large range of useful magnifications obtainable in a modern TEM, when a suitably thinned foil is available, was a key element in this analysis.


Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.


Author(s):  
J. L. Batstone ◽  
D.A. Smith

Recrystallization of amorphous NiSi2 involves nucleation and growth processes which can be studied dynamically in the electron microscope. Previous studies have shown thatCoSi2 recrystallises by nucleating spherical caps which then grow with a constant radial velocity. Coalescence results in the formation of hyperbolic grain boundaries. Nucleation of the isostructural NiSi2 results in small, approximately round grains with very rough amorphous/crystal interfaces. In this paper we show that the morphology of the rccrystallizcd film is dramatically affected by variations in the stoichiometry of the amorphous film.Thin films of NiSi2 were prepared by c-bcam deposition of Ni and Si onto Si3N4, windows supported by Si substrates at room temperature. The base pressure prior to deposition was 6 × 107 torr. In order to investigate the effect of stoichiomctry on the recrystallization process, the Ni/Si ratio was varied in the range NiSi1.8-2.4. The composition of the amorphous films was determined by Rutherford Backscattering.


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