摘要:

A new type TbFe sputtering target which is composed of multiphases (Tb metal, Fe metal, TbFe2intermetallic compound) is developed. Using this new type target, uniformity of composition of the films over a wider area is achieved in preparation of TbFe films by magnetron sputtering. Composition of the films depend on various preparation conditions and especially dc or rf induced selfbias voltage is an important factor which affects the composition. Films prepared from this target have good magneto‐optical properties for memory media.

ISSN:0734-2101    

DOI:10.1116/1.576992

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

This paper investigates the sputter gas (Ne, Ar, and Kr) influences on magnetic properties of Fe/SiO2multilayer film. The magnetostriction changes due to Fe layer thickness are strongly dependent on sputter gas species. This phenomenon cannot be explained only by Fe crystal orientation change. X‐ray photoelectron spectroscopy analysis indicates the magnetostriction change is also related to the Fe–Si‐O mixed state formed between Fe and SiO2layers, and to the thickness of the region. Ne improves the soft‐magnetic properties of Fe/SiO2film, but Kr deteriorates the properties. This result is thought to be caused by the difference in magnetic anisotropy dispersion due to Fe crystal grain size. Saturation magnetization of 1.72 T, hard‐axis coercivity of 0.3 Oe, and relative permeability (at 5 MHz) of more than 5000 are achieved under nearly zero magnetostriction in Ne80Ar20ion‐beam‐sputtered Fe/SiO2(10/2.5 nm) film, with no post annealing.

ISSN:0734-2101    

DOI:10.1116/1.577046

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Silver has been coated onto various base metals by planar‐magnetron (PM) sputtering to provide interlayers for diffusion welding. The vacuum‐coating process consisted of two stages: (1) sputter etching of the base metals to remove surface oxide layers, followed by (2) vapor deposition of high‐purity silver onto the clean surfaces. The silvers surfaces were diffusion welded at elevated pressure (207 MPa) and temperatures (483–673 K). The structures of the diffusion‐welded‐silver interlayer and the ‘‘as‐deposited’’ coatings were determined using optical metallography and electron microscopy. The as‐deposited structure consists of fine columnar grains ∼0.25 μm in diameter, perpendicular to the base‐metal surface with the axes of the columns oriented along the [111] crystallographic direction. These grains contain a high density of growth twins ∼15 nm thick. The diffusion‐welded‐silver interlayer consists mostly of large recrystallized grains (>1 mm in diameter) containing a high density of annealing twins. However, a significant amount of the interlayer has not recrystallized. Additionally, the diffusion‐welded‐silver (silver‐silver) interface consists of a high‐angle grain boundary often formed between recrystallized and nonrecrystallized regions. For various base metals, the tensile strengths of diffusion‐welded‐silver joints fabricated using PM sputter deposition were found to be equal to or greater than previously reported strengths for those fabricated using brazing, electroplating, or other vapor‐deposition methods. Tensile properties of diffusion‐welded‐silver joints fabricated using PM sputter‐deposition were also found to be more reproducible than properties previously reported for joints fabricated using hot‐hollow cathode (HHC) evaporation. Torsion tests of the diffusion‐welded‐silver joints revealed that the yield stress and strain‐hardening rates in the interlayer are much higher than corresponding values for high‐purity annealed bulk silver, although the maximum (steady‐state) stresses are nearly identical. These results may be at least partially explained by the high twin density in the recrystallized silver and also the very fine microstructure of the nonrecrystallized regions.

ISSN:0734-2101    

DOI:10.1116/1.577064

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

A particle model of energetic electron transport in sputtering magnetron discharges is presented. The model assumes time‐independent magnetic and electric fields and supposes that scattering by neutral atoms is the dominant transport mechanism. Without scattering, we find that some orbits are confined indefinitely. Using the differential cross sections for elastic, excitation, and ionization collisions in argon, we perform a Monte Carlo simulation of the electrons emitted by ion bombardment of a planar magnetron cathode to predict the spatial distribution of ionization. We find good agreement with experimental measurements of the radial profile of ion flux to the cathode and of the axial profile of optical emission.

ISSN:0734-2101    

DOI:10.1116/1.577093

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

The temperature behavior of the deposition rate of amorphous, hydrogenated carbon films is analyzed both experimentally and theoretically. A reactor based on the supersonic expansion of an arc plasma is used. The film thickness is measured usinginsituHe–Ne ellipsometry. The surface temperature is measured with thermocouples. Comparison of the presented model with the experimental results suggests that the deposited atoms and radicals diffuse over the surface in a weakly bound, adsorbed layer before they are incorporated in the film. Direct incorporation upon chemisorption is improbable.

ISSN:0734-2101    

DOI:10.1116/1.576403

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

ZnS:Mn thin films were deposited by a radio frequency (rf) ion‐plating technique. The microstructure of the films consisted of a columnar structure and had no dead layer. The grain size was larger than that of films deposited by thermal evaporation. As the dc accelerating voltage increased, the peak intensities of cubic(111) x‐ray diffraction became large and the full widths of half‐maximum (FWHM) decreased somewhat. It is suggested that energies of the ionized and neutral molecules is increased by the dc field. Electroluminescent (EL) properties of the ZnS:Mn thin films prepared by the rf ion‐plating technique have been investigated. As the rf power and the dc accelerating voltage increased, the luminance versus the applied voltage (L–V) curve shifted to lower applied voltage. When the dc accelerating voltage was too large, theL–Vcurve shifted to higher voltage and the maximum luminance decreased because the substrate insulating layer was degraded. The EL device with the ZnS:Mn layer of 1.0 μm thickness luminesced up to 1500 cd/m2(1 kHz) without post‐deposition annealing.

ISSN:0734-2101    

DOI:10.1116/1.576416

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Adsorption and thermal dissociation of Si2H6on Si(100)2×1 surfaces has been studied using electron energy loss spectroscopy (EELS) and reflection high‐energy electron diffraction (RHEED). Surface reactions were followed by recording the intensities and the positions of EELS peaks associated with dangling bonds on the initial 2×1 surface, surface Si–H bonds, and the appearance of dangling bonds due to Si dimer bond rupture together with the relative intensities of the integral and half‐order RHEED diffraction spots. The results indicate that with continued disilane exposure, Si2H6is dissociatively chemisorbed onto dangling bond sites on Si(100) and the initially adsorbed species (probably SiH3) further dissociate to form a mixed (2×1):H monohydride and (1×1)::2H dihydride surface. The mixed surface is then slowly converted to a (1×1)::2H surface through further reactions with Si2H6. While the Si(100)2×1 dangling bonds were saturated at Si2H6doses of ≂5×1015cm−2, much higher doses (≂2×1017cm−2) were required to obtain a dihydride‐saturated surface. Saturated (1×1)::2H surfaces were annealed to successively higher temperaturesTafor 15 s each. AtTa=655 K, hydrogen was evolved leading to the reestablishment of a mixed (2×1):H+(1×1)::2H surface. Most of the remaining dihydride was converted to monohydride at temperatures between 705 and 725 K. The 2×1 dangling‐bond EELS peak reemerged atTa=765 K and the clean‐surface 2×1 EELS spectrum, signaling the evolution of the remaining H from the new epitaxial Si layer, was obtained after annealing at 955 K. Implications of these results for Si growth by atomic‐layer epitaxy is discussed.

ISSN:0734-2101    

DOI:10.1116/1.576356

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

We have grown ultrathin films of layered transition metal dichalcogenides (MoSe2,NbSe2) heteroepitaxially on cleaved faces of mica (muscovite). This is the first success in the heteroepitaxial growth between highly heterogeneous layered materials having different crystal structures and lattice constants that differ by as much as 58%. The lattice matching condition is greatly loosened in those cases because the growth proceeds with weak van der Waals forces between the substrate and the grown layer. This opens a new way to fabricate a heterostructure composed of many kinds of layered materials having various physical and chemical properties.

ISSN:0734-2101    

DOI:10.1116/1.576983

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Stress from the overlay conductor patterns in ion‐implanted magnetic bubble memory devices has been investigated using computer simulations (Boundary Element Method). In the case of the conventional SiO2spacer which lays under the conductors, the concentrated stress at the edge of the conductors is transferred to the garnet directly. In order to reduce the stress, an elastically ‘‘soft’’ material, such as polyimide, was introduced as the spacer. The simulation shows that the stress under the polyimide spacer is reduced to about 1/3 of that under the SiO2spacer. This is caused both by the internal stress relaxation in the conductors themselves and by the stress dispersion effect of polyimide. The devices with the polyimide spacer were evaluated and showed no influence of the conductor stress.

ISSN:0734-2101    

DOI:10.1116/1.576990

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Cadmium telluride films have been grown by a modified close‐spaced vapor transport technique under different argon pressures (Pg) to get variable grain size and crystalline film properties. These films have been studied in terms of the variations of their structural and optical properties. Using SEM and microanalysis measurements it has been found that films grown at low pressures (∼1.5 mTorr) have a constant grain size; whereas, for films grown at highPg’s (∼50 Torr), inhomogeneities in grain size and a large density of defects are observed. Photoluminescence spectra taken at different regions in the different films are in good agreement with the presence of Cd vacancies and defects due to the growth process. The presence of an intense exciton‐related luminescence peak indicates good crystalline quality grains.

ISSN:0734-2101    

DOI:10.1116/1.576991

出版商:American Vacuum Society    

年代:1990

数据来源: AIP