TiNi Shape Memory Alloys for MEMS: Thin Film Deposition, Thermophysical Properties and Laser Micromachining Characteristics

2007 ◽  
Vol 539-543 ◽  
pp. 3151-3156
Author(s):  
S.T. Davies

The growth of TiNi thin films by ion beam sputter deposition using a Kaufmann type ion source is described. Argon ions are used to sputter separate Ti and Ni targets to deposit nearequiatomic TiNi thin films. Typically, ion energies and current densities of 1500 eV and 1 mA cm-2 respectively are used, with an argon overpressure of around 0.05 mtorr, to achieve deposition rates of order 1 μm hr-1. The thermophysical properties of the deposited films were investigated by thermal imaging. Patterning of TiNi films and foils with micrometre resolution using KrF excimer laser ablation at 248 nm wavelength, with beam fluence up to 2.5 J cm-2, 15 ns pulse duration and pulse rates up to 100 Hz has also been investigated.

1993 ◽  
Vol 316 ◽  
Author(s):  
BERTILO E. KEMPF

ABSTRACTTitanium metal is sputtered by ion beams using a Kaufman-type ion source with carbondioxide as working gas. Deposition takes place on watercooled substrates of silicon and InP. The films obtained are amorphous; they adhere excellently. SEM-pictures reveal a featureless dense fracture and a smooth surface. Despite a carbon content of 9 at % the films are highly transparent in the visible and near infrared wavelength range. Refractive indices center around 2.15 at values typically found for amorphous TiO2. The electrical properties are characterized by dielectric constant of ε = 26 ± 3, leakage current densities at breakdown of jL = 3.65 . 10-3 A/cm2 and breakdown fields EB > 1 MeV/cm.


2016 ◽  
Vol 23 (1) ◽  
pp. 182-186 ◽  
Author(s):  
Lin Zhou ◽  
Mourad Idir ◽  
Nathalie Bouet ◽  
Konstantine Kaznatcheev ◽  
Lei Huang ◽  
...  

One-dimensional ion-beam figuring (1D-IBF) can improve grazing-incidence reflective optics, such as Kirkpatrick–Baez mirrors. 1D-IBF requires only one motion degree of freedom, which reduces equipment complexity, resulting in compact and low-cost IBF instrumentation. Furthermore, 1D-IBF is easy to integrate into a single vacuum system with other fabrication processes, such as a thin-film deposition. The NSLS-II Optical Metrology and Fabrication Group has recently integrated the 1D-IBF function into an existing thin-film deposition system by adding an RF ion source to the system. Using a rectangular grid, a 1D removal function needed to perform 1D-IBF has been produced. In this paper, demonstration experiments of the 1D-IBF process are presented on one spherical and two plane samples. The final residual errors on both plane samples are less than 1 nm r.m.s. The surface error on the spherical sample has been successfully reduced by a factor of 12. The results show that the 1D-IBF method is an effective method to process high-precision 1D synchrotron optics.


1995 ◽  
Vol 388 ◽  
Author(s):  
J. C. Olson ◽  
M. O. Thompson ◽  
H. A. Davis ◽  
D. J. Rej ◽  
W. J. Waganaar ◽  
...  

AbstractDiamond-like Carbon(DLC) films have been deposited at Los alamos National Laboratory by pulsed ion beam ablation of graphite targets. the targets are illuminated by an intense beam of hydrogen, carbon, and oxygen ions at a fluence of 15-45 J/cm2. Ion energies are on the order of 350 keV, with beam current rising to 35 kA over a 400 ns ion current pulse.Raman spectra of the deposited films indicate an increasing ratio of sp3 to sp2 bonding as the substrate is moved further away from the target and further off the target normal. Using a thin film platinum resistor at various positions, we have measured the heating of the substrate surface due to the kinetic energy and heat of condensation of the ablated material. Plume power density and energy input are inferred from the temperature measurements. This information is used to determine if substrate heating is responsible for the lack of DLC in positions close to the target and near the target normal.


2000 ◽  
Vol 647 ◽  
Author(s):  
Bernd Stritzker ◽  
Jürgen W. Gerlach ◽  
Stephan Six ◽  
Bernd Rauschenbach

AbstractIon beam assisted deposition, i.e., the bombardment of thin films with a beam of energetic particles has become a highly developed tool for the preparation of thin films. This technique provides thin films and coatings with modified microstructure and properties. In this paper examples are presented for the modifying of the structure: in-situ modification of texture during ion beam assisted film growth and ion beam enhanced epitaxy.The biaxial alignment of titanium nitride films prepared on Si(111) by nitrogen ion beam assisted deposition at room temperature was studied. The bombardment perpendicular to the surface of the substrate causes an {001} alignment of crystallites. A 55° ion beam incidence angle produces both a {111} orientation relative to the surface and a {100} orientation relative to the ion beam. This results in a totally fixed orientation of the crystallites. The texture evolution is explained by the existence of open channeling directions.Epitaxial, hexagonal gallium nitride films were grown on c-plane sapphire by low-energy nitrogen ion beam assisted deposition (≤ 25 eV). The ion energy was chosen to be less than the corrected bulk displacement energy to avoid the formation of ion-induced point defects in the bulk. The results show that GaN films with a nearly perfect {0002} texture are formed which have superior crystalline quality than films grown without ion irradiation. The mosaicity and the defect density are reduced.By applying an assisting ion beam during pulsed laser deposition of aluminum nitride on the c-plane of sapphire, epitaxial, hexagonal films could be produced. The results prove the beneficial influence of the ion beam on the crystalline quality of the films. An optimum ion energy of 500 eV was found where the medium tilt as well as the medium twist of the crystallites was minimal.


Author(s):  
Dudley M. Sherman ◽  
Thos. E. Hutchinson

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.


Author(s):  
M. Grant Norton ◽  
C. Barry Carter

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.


2019 ◽  
Vol 7 (36) ◽  
pp. 20733-20741 ◽  
Author(s):  
Mehri Ghasemi ◽  
Miaoqiang Lyu ◽  
Md Roknuzzaman ◽  
Jung-Ho Yun ◽  
Mengmeng Hao ◽  
...  

The phenethylammonium cation significantly promotes the formation of fully-covered thin-films of hybrid bismuth organohalides with low surface roughness and excellent stability.


2013 ◽  
Vol 37 (3) ◽  
pp. 873-883 ◽  
Author(s):  
Tsai-Cheng Li ◽  
Rwei-Ching Chang ◽  
Yen-Choung Li

Silver conductive thin films deposited on glass and polyimide substrates by using ink jet printing are studied in this work. Characterization of the printed thin films and comparison with sputtered films are investigated. The micro texture, residual stress, adhesion, hardness, optical reflectance, and electric resistance of the thin films are discussed. The result shows that the ink jet printing has the possibility to replace sputtering in thin film deposition, especially for the polymer substrates.


1990 ◽  
Vol 206 ◽  
Author(s):  
Hellmut Haberland ◽  
Martin Karrais ◽  
Martin Mall

ABSTRACTAtoms are gas discharge sputtered from a solid target. They are condensed to form clusters using the gas aggregation technique. An intense beam of clusters of all solid materials can be obtained. Up to 80 % of the clusters can be ionised without using additional electron impact ionisation. Total deposition rates vary between 1 and 1000 Å per second depending on cluster diameter, which can be varied between 3 and 500 nm. Thin films of Al, Cu, and Mo have been produced so far. For non accelerated beams a weakly adhering mostly coulored deposit is obtained. Accelerating the cluster ions this changes to a strongly adhering film, having a shiny metallic appearance, and a very sharp and plane surface as seen in an electron microscope. The advantages compared to Kyoto ICB-method are: easy control of the cluster size, no electron impact ionisation, high degree of ionisation, and sputtering is used instead of thermal evaporation, which allows the use of high melting point materials.


Author(s):  
Cornel Tarabasanu Mihaila ◽  
Lavinia G. Hinescu ◽  
Cristian Boscornea ◽  
Carmen Moldovan ◽  
Mihai E. Hinescu

The paper presents the synthetic routes for obtaining some organic semiconductors and their characterization in order to use in thin film deposition for gas sensing devices. An original technique was used to control the molecular weight of polymeric phthalocyanine. We have fabricated devices consisting of evaporated thin films of copper, nickel, and iron phthalocyanines onto interdigital electrodes and estimated the electrical conductivity by in-situ measurements. The films were evaporated onto substrates (gold or aluminum) which were entirely integrated in the standard CMOS (capacitor metal oxide semiconductor) technology. The objectives of this work were to improve the synthesis methods of organic metal-complex tetraizoindoles and their polymers and to evaluate their electrical response and thermal stability as evaporated thin films. We have also investigated the variation of polymers conductivity and sublimation yield with the average molecular weight. We found that for polymeric phthalocyanines, the thermal stability was higher than for Pcs monomers. The stability of polymers increased with the average molecular weight.


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