The Dependence of Aluminum/Tungsten Reaction on Crystalline Phases of Cvd Tungsten

1990 ◽  
Vol 181 ◽  
Author(s):  
Y. Harada ◽  
H. Onoda ◽  
S. Madokoro
Keyword(s):  
Sheet Resistance ◽  
Alloy Film ◽  
Crystalline Phases ◽  
Si Substrates ◽  
Tungsten Hexafluoride ◽  
Cu Alloy ◽  
Grain Structures ◽  
The Difference ◽  
Deposition Conditions ◽  
Resistance Difference

ABSTRACTThe reaction between Al and CVD-W films has been studied. Al/α-W/Si and Al/β-W/Si structures were prepared by deposition on different Si substrates by changing deposition conditions using silane reduction of tungsten hexafluoride, followed by Al-Si-Cu alloy film sputter deposition. The sheet resistance of Al/α-W/Si structure is higher than that of Al/β-W/Si structure after 500°C annealing. RBS measurements show that the W diffusion into Al occurs in both structures after annealing, and the reaction between α-W and Al takes place easily compared with that between β-W and Al. This causes the sheet resistance difference. The activation energies for the W diffusion into Al, however, are almost the same in both structures. When CVD-W films are exposed to air after removal from the reactor, the sheet resistance of β-W film increases according to the exposure time, while that of α-W film does not. AES measurements indicate that the β-W film absorbs more oxygen than the α-W because of the difference of grain structures. The resistance increase of β-W film is caused by the oxygen that is absorbed from air. Our results indicate that the oxygen in the β-W layer suppresses the W diffusion into Al. Once the reaction begins, however, the diffusion into Al does not depend on crystalline phases of CVD-W.

Effect of Magnetic Fields on the Resistance and Microstructure of Al-Cu Alloy during Solidification Processing

2011 ◽  
Vol 287-290 ◽  
pp. 2916-2920
Author(s):  
Chun Yan Ban ◽  
Peng Qian ◽  
Xu Zhang ◽  
Qi Xian Ba ◽  
Jian Zhong Cui
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Turning Points ◽  
Probe Method ◽  
Solidification Processing ◽  
Ac Magnetic Field ◽  
Dc Magnetic Field ◽  
Cu Alloy ◽  
The Difference ◽  
Good Agreement

The resistance of Al-21%Cu alloy under no magnetic field, DC magnetic field and AC magnetic field from liquid to solid was measured by a four-probe method. The difference of resistance versus temperature curves (R-T curves) was analyzed. It is found that the R-T curves of Al-21%Cu alloy are monotone decreasing and have two obvious turning points. Under DC magnetic field, the liquidus and solidus temperatures of the alloy both decrease, while under AC magnetic field, the liquidus and solidus temperatures both increase. There is a good agreement between the microstructure of quenching sample and R-T curves. The mechanism of the effect of magnetic fields was discussed.

2. Adhesion of the plasma-polymerized fluorocarbon films to silicon substrates The adhesion properties of the plasma-polymerized FC coatings were determined by using a test, already employed by Yasuda and Sharma [13] (see Fig. 1 and Table 1) in which the silicon substrates coated with plasma FC-films were boiled in a0.9% sodium chloride solution. The FC thin films produced in the processes 1 and 2 were lifted after a very short time (15 minutes). Coatings generated in process 3 were lifted after the second cycle of boiling. The films produced in processes 4 and 5 withstood the complete test procedure. The results are shown in Fig. 3. The poor adhesion of the polymerized films in the first two processes is due to the fact that these processes do not involve a plasma pre-treatment process. The difference between processes 1 and 3 is only in the plasma pre-treatment (process 1 does not contain the pre-treatment step of the silicon surface). The fluorocarbon films deposited by processes 4 and 5 have shown the best adhesion. These test results indicate that the plasma pre-treatment is very important and necessary for a good adhesion of the FC coatings to the silicon surfaces. 2.3. Patterning of FC films 2.3.1. Patterning through resist mask. The patterning of the FC films through a photoresist mask (conventional All resist AR-P351) was examined after deposition for process No. 5. Different coating parameters were investigated to improve the adhesion of the resist to the FC surface. The best adhesion results were obtained using the process parameters, shown in Table 3. Differences in the thickness uniformity of so-deposited resists were in a range below 5%. The samples were etched in a pure oxygen plasma in an RIE-system after the lithography steps (pre-bake, exposure, development, post-bake). A resolution of 2 /xm was obtained. A significant increase in the surface energy was not observed after resist stripping. The sessile contact angle of water was 103°. 2.3.2. Lift-off process for patterning thin plasma polymerized FC films. A lift-off process was also examined to pattern the thin FC films. The lithography steps were used before the plasma polymerization process was carried out (Fig. 2). A standard resist AR-P351 was coated directly onto the Si substrates. After all lithography

2014 ◽  
pp. 275-278
Keyword(s):  
Treatment Process ◽  
Test Procedure ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
Fluorocarbon Films ◽  
Si Substrates ◽  
Complete Test ◽  
The Difference ◽  
Pre Treatment ◽  
Lift Off

scholarly journals Three-dimensional Simulation of Dendritic Grain Structures of Gas-atomized Al-Cu Alloy Droplets.

1998 ◽  
Vol 38 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Yi Hyun Chang ◽  
Sang Mok Lee ◽  
Kyong Yee Lee ◽  
Chun Pyo Hong
Keyword(s):  
Three Dimensional ◽  
Cu Alloy ◽  
Grain Structures ◽  
Dimensional Simulation

scholarly journals Effect of wet KOH etching on structural properties of GaN nanowires grown on patterned SiOx/Si substrates

2021 ◽  
Vol 2103 (1) ◽  
pp. 012098
Author(s):  
V V Lendyashova ◽  
K P Kotlyar ◽  
V O Gridchin ◽  
R R Reznik ◽  
A I Lihachev ◽  
...  
Keyword(s):  
Structural Properties ◽  
Si Substrates ◽  
Gan Nanowires ◽  
The Difference ◽  
Koh Etching

Abstract The possibility of the controlled removal of GaN nanowires (NWs) from an SiOx inhibitor layer of patterned SiOx/Si substrates has been demonstrated. It has been found that the wet KOH etching preserves the selectively grown GaN NWs on Si surface, whereas the GaN NWs grown on inhibitor SiOx layer are removing. The effect is described by the difference in polarity between GaN NWs grown on a Si surface and NWs grown on a SiOx inhibitor layer.

Influence of Interfacial Mixing on Thermal Boundary Conductance Across a Chromium/Silicon Interface

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Patrick E. Hopkins ◽  
Pamela M. Norris ◽  
Robert J. Stevens ◽  
Thomas E. Beechem ◽  
Samuel Graham
Keyword(s):  
Electron Spectroscopy ◽  
Finite Thickness ◽  
Thermal Conductance ◽  
Phase Region ◽  
Two Phase ◽  
Thermal Boundary Conductance ◽  
Si Substrates ◽  
Interfacial Mixing ◽  
Silicon Interface ◽  
Deposition Conditions

The thermal conductance at solid-solid interfaces is becoming increasingly important in thermal considerations dealing with devices on nanometer length scales. Specifically, interdiffusion or mixing around the interface, which is generally ignored, must be taken into account when the characteristic lengths of the devices are on the order of the thickness of this mixing region. To study the effect of this interfacial mixing on thermal conductance, a series of Cr films is grown on Si substrates subject to various deposition conditions to control the growth around the Cr∕Si boundary. The Cr∕Si interfaces are characterized with Auger electron spectroscopy. The thermal boundary conductance (hBD) is measured with the transient thermoreflectance technique. Values of hBD are found to vary with both the thickness of the mixing region and the rate of compositional change in the mixing region. The effects of the varying mixing regions in each sample on hBD are discussed, and the results are compared to the diffuse mismatch model (DMM) and the virtual crystal DMM (VCDMM), which takes into account the effects of a two-phase region of finite thickness around the interface on hBD. An excellent agreement is shown between the measured hBD and that predicted by the VCDMM for a change in thickness of the two-phase region around the interface.

Interaction of elements in carbon-graphite—Al—Mg—Zn—Cu melt system under combined action of temperature and pressure

2021 ◽  
pp. 514-518
Author(s):  
N.Yu. Miroshkin ◽  
V.A. Gulevsky ◽  
S.N. Tsurikhin ◽  
A.I. Bogdanov ◽  
L.M. Gurevich ◽  
...  
Keyword(s):  
Matrix Alloy ◽  
Impregnation Process ◽  
Active Elements ◽  
Cu Alloy ◽  
Inner Surface ◽  
The Matrix ◽  
Combined Action ◽  
Temperature And Pressure ◽  
The Difference ◽  
Titanium Compounds

Redistribution of chemically active elements is established on its inner surface of pores and at the interface with the alloy when impregnating carbon-graphite framework with Al—Mg—Zn—Cu alloy at temperature of 800 °C under pressure of up to 3 MPa. In this case, change in the solubility of melt elements in aluminum is possible as result of the combined action of temperature and pressure in the impregnation process, created due to the difference in the coefficients of thermal and thermal expansion of the matrix alloy, and the material of the impregnation device during impregnation. Titanium compounds are found in the pores filled with metal that are not added to the matrix alloy, but are formed as result of the contact of the matrix alloy melt with the walls of the impregnation device.

Selective arrangement of vesicles on artificial lipid membrane by biotin-avidin interaction

2021 ◽  
Author(s):  
Kai Hashino ◽  
Daiya Mombayashi ◽  
Yuto Nakatani ◽  
Azusa Oshima ◽  
Masumi Yamaguchi ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
Lipid Bilayers ◽  
Liquid Crystalline ◽  
Lipid Membrane ◽  
Unsaturated Lipid ◽  
Si Substrates ◽  
Phase Domain ◽  
Unsaturated Lipids ◽  
Lipid Mixtures ◽  
The Difference

Abstract Lipid bilayers suspended over microwells on Si substrates are promising platforms for nanobiodevices that mimic cell membranes. Using the biotin-avidin interaction, we have succeeded in selectively arranging vesicles on the freestanding region of a lipid bilayer. When ternary lipid mixtures of saturated lipid, unsaturated lipid, and cholesterol are used, they separate into liquid-order (Lo) and liquid-crystalline (Lα) domains. A freestanding lipid bilayer prefers the Lα-phase over the Lo-phase because of the difference in their flexibility. In addition, the type of biotinylated lipid determines whether it is localized in the Lα-phase domain or the Lo-phase domain. As a result, the biotinylated unsaturated lipids localized in the Lα-phase domain aggregate in the freestanding lipid bilayer, and vesicles labeled with biotin selectively bind to the freestanding lipid bilayer by the biotin-avidin interaction. This technique helps to introduce biomolecules into the freestanding lipid bilayer of nanobiodevices via vesicles.

scholarly journals Multilayered Sn-Zn/Zn/Cu Alloy Film Electrode Prepared by Electroplating Method for Lithium Secondary Batteries

2003 ◽  
Vol 71 (12) ◽  
pp. 1070-1072 ◽  
Author(s):  
Shingo KITAMURA ◽  
Lianbang WANG ◽  
Shigeo TANASE ◽  
Keigo OBATA ◽  
Tetsuo SAKAI
Keyword(s):  
Alloy Film ◽  
Film Electrode ◽  
Lithium Secondary Batteries ◽  
Cu Alloy

Mechanism of Stress-Enhanced Solid-Phase Epitaxy

1991 ◽  
Vol 237 ◽  
Author(s):  
T. K. Chaki
Keyword(s):  
Hydrostatic Pressure ◽  
Point Defects ◽  
Solid Phase ◽  
Amorphous Solid ◽  
Amorphous Layer ◽  
Crystalline Phases ◽  
Self Diffusion ◽  
Bending Stresses ◽  
Enhanced Mobility ◽  
The Difference

ABSTRACTEnhancement of solid-phase epitaxial growth (SPEG) due to hydrostatic pressures and bending stresses is explained by stress-enhanced mobility of point defects in the amorphous solid. The crystallization is by the adjustment of atomic positions in the vicinity of the crystallization/amorphous (c-a) interface due to self-diffusion in the amorphous phase, assisted by a free energy decrease equal to the difference in free energies between the amorphous and crystalline phases. Due to a mismatch in the bulk moduli between the amorphous and crystalline phases, the application of a hydrostatic pressure can develop tensile stresses in the amorphous layer near the c-a interface. Non-hydrostatic stresses in the amorphous layer enhance the mobility of point defects in the amorphous layer and, therefore, an enhancement of the SPEG rate. In the cases of both hydrostatic pressure and bending, the enhancement occurs in the tensile side, indicating that vacancy-like mechanism is predominant in SPEG.

Variations in the Effects of Implanting Al at Different Concentrations into SiC

2006 ◽  
Vol 527-529 ◽  
pp. 831-834
Author(s):  
Kenneth A. Jones ◽  
T.S. Zheleva ◽  
Pankaj B. Shah ◽  
Michael A. Derenge ◽  
Jaime A. Freitas ◽  
...  
Keyword(s):  
Sheet Resistance ◽  
Epitaxial Layer ◽  
Partial Dislocation ◽  
Annealing Temperature ◽  
Stacking Faults ◽  
Sheet Resistivity ◽  
Complex Defect ◽  
Annealing Temperatures ◽  
Peak Intensity ◽  
The Difference

SiC samples implanted at 600°C with 1018, 1019, or 1020 cm-3 of Al to a depth of ~ 0.3 μm and annealed with a (BN)AlN cap at temperatures ranging from 1300 – 1700°C were studied. Some of the samples have been co-implanted with C or Si. They are examined using Hall, sheet resistivity, CL, EPR, RBS, and TEM measurements. In all instances the sheet resistance is larger than a comparably doped epitaxial layer, with the difference being larger for samples doped to higher levels. The results suggest that not all of the damage can be annealed out, as stable defects appear to form, and a greater number or more complex defects form at the higher concentrations. Further, the defects affect the properties of the Al as no EPR peak is detected for implanted Al, and the implanted Al reduces the AlSi peak intensity in bulk SiC. CL measurements show that there is a peak near 2.9941 eV that disappears only at the highest annealing temperature suggesting it is associated with a complex defect. The DI peaks persist at all annealing temperatures, and are possibly associated with a Si terminated partial dislocation. TEM analyses indicate that the defects are stacking faults and/or dislocations, and that these faulted regions can grow during annealing. This is confirmed by RBS measurements.

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