Stress Controlled Magneto-Mechanical Instability In Terfenol-D Thin Films

1997 ◽  
Vol 505 ◽  
Author(s):  
Quanmin Su ◽  
Y. Wen ◽  
Manfred Wuttig
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Mechanical Response ◽  
Substrate Material ◽  
Recrystallization Temperature ◽  
Mechanical Instability ◽  
Si Substrates ◽  
Different Temperatures ◽  
Film Substrate ◽  
Selection Of

ABSTRACTThe magneto-mechanical properties of Terfenol-D thin films deposited on Si substrates were studied by magnetic and mechanical measurements of film/substrate composite cantilevers. The AE effect and mechanical damping of the film were measured simultaneously. The stress in the film was controlled by annealing and deposition at different temperatures as well by the selection of the substrate material below the recrystallization temperature and determined to vary from -500 MPa, compression, in as deposited films to +480MPa, tension, in annealed films. This paper highlights the magneto-mechanical response of tensioned 1 m nanocrystalline Terfenol-D films on 50 Pim Si substrates display a pronounced damping maximum at a magnetic field of about 1.5kOe oriented perpendicular to the plane of the film. The phenomenon is critically dependent on the orientation of the magnetic field and is the result of a magneto-mechanical instability in the Terfenol film.

Thermo-Mechanical Properties of Terfenol-D Thin Films

1994 ◽  
Vol 360 ◽  
Author(s):  
Quanmin Su ◽  
Y. Zheng ◽  
Manfred Wuttig
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Amorphous Material ◽  
Recrystallization Temperature ◽  
Dynamic Measurements ◽  
Si Substrates ◽  
Damping Characteristics ◽  
Δe Effect ◽  
Film Substrate ◽  
Deposited Films

AbstractThe thermo-mechanical properties of Terfenol-D thin films deposited on Si substrates werestudied by static and dynamic measurements of film/substrate composite cantilevers. The Curie transition, δE effect and mechanical damping of the film were measuredsimultaneously. The stress in the film was controlled by annealing below the recrystallization temperature and determined to vary from -500 MPa, compression, in as deposited films to +480 MPa, tension, in annealed films. The Curie temperature shifts from 80ºC to 140ºC as the tension increases while the structure of the film remains amorphous. The stress change induced by annealing also drastically effects the film's damping characteristics. The δE effect of the amorphous material, about 20%, wasused to estimate the magnetostriction, λs≈4.10-3.

Defects in β-SiC thin films grown on α-SiC substrates

1988 ◽  
Vol 46 ◽  
pp. 568-569
Author(s):  
Karren L. More
Keyword(s):  
Thin Films ◽  
Semiconductor Device ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Substrate Material ◽  
Growth Interface ◽  
Si Substrates ◽  
Thermal Expansion Coefficients ◽  
Device Applications ◽  
Expansion Coefficients

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.

Interfacial adhesion of nanoporous zeolite thin films

2006 ◽  
Vol 21 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Lili Hu ◽  
Junlan Wang ◽  
Zijian Li ◽  
Shuang Li ◽  
Yushan Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Interfacial Adhesion ◽  
Interfacial Strength ◽  
Future Generation ◽  
In Situ Growth ◽  
Seeded Growth ◽  
Si Substrates ◽  
Film Substrate

Nanoporous silica zeolite thin films are promising candidates for future generation low-dielectric constant (low-k) materials. During the integration with metal interconnects, residual stresses resulting from the packaging processes may cause the low-k thin films to fracture or delaminate from the substrates. To achieve high-quality low-k zeolite thin films, it is important to carefully evaluate their adhesion performance. In this paper, a previously reported laser spallation technique is modified to investigate the interfacial adhesion of zeolite thin film-Si substrate interfaces fabricated using three different methods: spin-on, seeded growth, and in situ growth. The experimental results reported here show that seeded growth generates films with the highest measured adhesion strength (801 ± 68 MPa), followed by the in situ growth (324 ± 17 MPa), then by the spin-on (111 ± 29 MPa). The influence of the deposition method on film–substrate adhesion is discussed. This is the first time that the interfacial strength of zeolite thin films-Si substrates has been quantitatively evaluated. This paper is of great significance for the future applications of low-k zeolite thin film materials.

The Use of Energy Dispersive Diffractometry to Measure the Thickness of Metal and Glass Thin Films

1981 ◽  
Vol 25 ◽  
pp. 365-371
Author(s):  
Glen A. Stone
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Single Crystal Silicon ◽  
Substrate Material ◽  
Silicon Wafers ◽  
Energy Dispersive ◽  
Crystal Silicon ◽  
X Ray ◽  
Phosphosilicate Glass ◽  
Film Substrate

This paper presents a new method to measure the thickness of very thin films on a substrate material using energy dispersive x-ray diffractometry. The method can be used for many film-substrate combinations. The specific application to be presented is the measurement of phosphosilicate glass films on single crystal silicon wafers.

LUMINESCENT PROPERTIES OF SOL-GEL DEPOSITED Eu:TiO2 THIN FILMS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 769-773 ◽  
Author(s):  
M. GARCIA-ROCHA ◽  
A. CONDE-GALLARDO ◽  
I. HERNANDEZ-CALDERON ◽  
R. PALOMINO-MERINO
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Glass Substrates ◽  
Corning Glass ◽  
Different Temperatures ◽  
Hecd Laser

In this work we show the results on tile growth and optical characterization of TiO 2 thin films doped with Eu atoms. Eu:TiO2 films were grown at room temperature with different Eu concentrations by sol-gel on Si Corning glass substrates. A different crystalline structure is developed for the films deposited on Corning glass than those deposited on Si as observed from x-ray diffraction experiments. Room and low temperature photoluminescence (PL) was measured by using two different lines (325 and 442 nm) of a HeCd laser. A strong PL signal associated to the 5 D 0→7 F 2 transition from Eu +3 was observed. A better emission was obtained from those films deposited on Si substrates, Finally, the evolution of the PL signal is studied when the samples are annealed at different temperatures in O 2 atmosphere.

Admittance and Photoadmittance Spectroscopy of Zinc Oxide Layers Grown on p-Si Substrates by Spin Coating Method

2013 ◽  
Vol 200 ◽  
pp. 27-32
Author(s):  
Pawel Popielarski ◽  
Waclaw Bala ◽  
Kazimierz Paprocki
Keyword(s):  
Thin Films ◽  
Temperature Dependence ◽  
Dielectric Response ◽  
Ac Conductivity ◽  
Signal Amplitude ◽  
Zno Thin Films ◽  
Si Substrates ◽  
Universal Power Law ◽  
Coating Method ◽  
Different Temperatures

In this work, the dielectric response of ZnO thin films has been studied over a temperature range of 200 K - 550 K. The dielectric response of polycrystalline ZnO thin films in the frequency domain was measured from 42 Hz - to 5 MHz with a small AC signal amplitude at different temperatures. Influence of the light on conductivity has been also investigated. A universal power law relation was brought into picture to explain the frequency dependence of AC conductivity. The temperature dependence of AC conductivity was analyzed in detail. The activation energy obtained from the temperature dependence of AC conductivity was attributed to the shallow trap-controlled space charge conduction in the bulk of the sample.

Zone Melting Recrystallization of InSb Films on Oxidized Si Wafers

1983 ◽  
Vol 23 ◽  
Author(s):  
C.C. Wong ◽  
C.J. Keavney ◽  
H.A. Atwater ◽  
C.V. Thompson ◽  
H.I. Smith
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Eutectic Structure ◽  
Zone Melting ◽  
Molten Zone ◽  
Si Substrates ◽  
Novel Device ◽  
Device Structures ◽  
Insb Thin Films ◽  
Selection Of

ABSTRACTInSb thin films on oxidized Si wafers have been recrystallized using a strip heater to generate and scan a narrow molten zone across the film. Grains up to 3 × 10 mm have been produced. Crystallization proceeds in a faceted cellular fashion, the excess solute (Sb) being rejected into subboundaries which often lie along low-index crystallographic directions. A InSb-Sb eutectic structure forms at the subboundaries. The width of the single-crystal InSb between subboundaries is approximately 75 μm. The techniques of planar constriction and subboundary entrainment have been extended to InSb for the selection of single grains and the orelocation of subboundaries. This technology of producing InSb thin films on oxidized Si substrates max, be extendable to other III-V materials, and could lead to novel device structures through the integration of Si and III-V compound devices on the same substrate.

Hydrogen Gas Sensing Characterizations Based on Nanocrystalline SnO2 Thin Films Grown on SiO2/Si and Al2O3 Substrates

2017 ◽  
Vol 268 ◽  
pp. 244-248
Author(s):  
Abu Hassan Haslan ◽  
Imad Hussein Kadhim
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Gas Sensing ◽  
Sol Gel ◽  
Hydrogen Gas ◽  
Rutile Structure ◽  
Nanoparticle Distribution ◽  
Si Substrates ◽  
Coating Method ◽  
Different Temperatures

High-quality nanocrystalline (NC) SnO2 thin films were grown on SiO2/Si and Al2O3 substrates using sol–gel spin coating method. The structural properties, surface morphologies and gas sensing properties of the NC SnO2 were investigated. XRD measurements showed a tetragonal rutile structure and the diffraction peaks for NC SnO2 thin films grown on Al2O3 substrates outperformed those of NC SnO2 films grown on SiO2/Si substrates. The surface morphology of the annealed SnO2 thin films at 500 °C appeared as polycrystalline with uniform nanoparticle distribution. Hydrogen (H2) gas sensing performance of the NC SnO2 was examined for H2 concentrations ranging from 150 ppm to 1000 ppm at different temperatures (room temperature, 75 and 125 °C) for over 50 min. The room temperature sensitivities for H2 gas sensors based on NC SnO2 thin films grown on Al2O3 and SiO2/Si substrates was 2570% and 600%, respectively upon exposure to 1000 ppm of H2 gas. While the sensitivity values at 125 °C increased to 9200% and 1950%, respectively.

Direct measurement of mechanical properties of (Pb,La)TiO3 ferroelectric thin films using nanoindentation techniques

2001 ◽  
Vol 16 (4) ◽  
pp. 993-1002 ◽  
Author(s):  
M. Algueró ◽  
A. J. Bushby ◽  
M. J. Reece
Keyword(s):  
Thin Films ◽  
Plastic Deformation ◽  
Lead Titanate ◽  
Mechanical Response ◽  
High Spatial Resolution ◽  
Ferroelectric Thin Films ◽  
Intergranular Porosity ◽  
Major Mechanism ◽  
Wall Movement ◽  
Film Substrate

A procedure using nanoindentation with spherical tipped indenters is presented that allows separation of elastic, anelastic, and plastic contributions to the deformation of thin films. The procedure was demonstrated on a range of lanthanum-modified lead titanate (Pb,La)TiO3 (PTL) ferroelectric thin films. Indentation stiffness coefficients ranging from 110 to 147 GPa have been obtained depending on the microstructure and orientation of the PTL films. This coefficient was equivalent to (and so, can be directly compared with) Young's modulus of a nontextured, unpoled ceramic when films do not present preferred orientation. The trends of the anelastic contribution with the thickness, structure, microstructure, and stress level at the film/substrate interface of the films were consistent with it being produced by ferroelastic domain wall movement. Pore compaction was a major mechanism of plastic deformation for the PTL films. Grain size also affected plastic deformation, probably as a consequence of its correlation with intergranular porosity. The technique has a high spatial resolution (contact area < 10 μm2 for the results presented here), which allowed the mechanical homogeneity of the films to be studied and inhomogeneities to be identified from their mechanical response (elastic, anelastic, and plastic).

Correlation of film stress and the mechanical response of Au thin films

1996 ◽  
Vol 54 ◽  
pp. 856-857
Author(s):  
K.F. Jarausch ◽  
J.E. Houston ◽  
P.E. Russell
Keyword(s):  
Thin Films ◽  
Mechanical Response ◽  
Semiconductor Industry ◽  
Maximum Shear Stress ◽  
Effective Elastic Modulus ◽  
Film Stress ◽  
Strain Effect ◽  
Stress And Strain ◽  
Au Thin Films ◽  
Film Substrate

The investigation of the mechanical properties of nanostructured materials is critical to the continuing development of thin film technology. For example, the semiconductor industry must understand how stress and strain effect the electronic properties of superlattices and cause the delamination of metal interconnect films. A variety of nano-indentation techniques have been developed as tools to investigate the mechanical behavior of thin films. In a previous study the interfacial force microscope (IFM) was used to survey the mechanical response of 200nm thick Au films deposited on various substrates under various deposition conditions. By combining the methods of contact mechanics and classic indentation techniques, quantitative investigations of the effective elastic modulus and the maximum shear-stress at the plastic threshold were tabulated. The results indicated a large variation in these parameters for the various film/substrates, while the values were consistent over a single film/substrate. The observed variation could be explained by several factors: differences in the films morphology, adhesion to the substrate, or residual stress.

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