In Situ Study of Stresses in Ag/Cu Thin Film Multilayers During Deposition

1994 ◽  
Vol 356 ◽  
Author(s):  
Alison L. Shull ◽  
Howard G. Zolla ◽  
Frans Spaepen

AbstractAg/Cu multilayers are deposited onto a thin Si(100) cantilevered substrate in ultra high vacuum. During deposition, the force per unit width (F/w) in the multilayers is measured continuously from the substrate curvature by a laser scanning technique. Mechanical stability and sample temperature are monitored continuously. The evolution of stress in the film during a layer deposition depends on the thicknesses of the layers beneath it. During deposition of thicker layers of either Cu or Ag, we observe increasing tensile F/w at the start of each layer. The F/w increases up to a few N/m at ∼20 nm layer thickness, and then decreases. When the thickness of each layer is less than 30 nm, the tensile stress sometimes continues to decrease even after a new interface is created. This result does not support a model for the origin of compressive stress that is based on coherent propagation of compressive strain.

1988 ◽  
Vol 132 ◽  
Author(s):  
R. W. Siegel ◽  
J. A. Eastman

ABSTRACTUltrafine-grained ceramics have been synthesized by the production of ultrafine (2–20 nm) particles, using the gas-condensation method, followed by their in-situ, ultra-high vacuum consolidation at room temperature. These new nanophase ceramics have properties that are significantly improved relative to those of their coarser-grained, conventionally-prepared counterparts. For example, nanophase rutile (TiO2) with an initial mean grain diameter of 12 nm sinters at 400 to 600°C lower temperatures than conventional powders, without the need for compacting or sintering aids. The sintered nanophase rutile exhibits both improved microhardness and fracture characteristics. These property improvements result from the reduced scale of the grains and the increased cleanliness of the particle surfaces and the subsequently-formed grain boundaries. Research completed on the synthesis, characterization, and properties of nanophase ceramics is reviewed and the potential for using the nanophase synthesis method for engineering new and/or improved ceramics and composites is considered.


2020 ◽  
Vol 32 (7) ◽  
pp. 075501
Author(s):  
Muhammad Shamim Al Mamun ◽  
Hiroki Waizumi ◽  
Tsuyoshi Takaoka ◽  
Md Iftekharul Alam ◽  
Yudai Tanaka ◽  
...  

1999 ◽  
Vol 564 ◽  
Author(s):  
M. W. Kleinschmit ◽  
M. Yeadon ◽  
J. M. Gibson

AbstractOxide Mediated Epitaxy (OME) shows promise as a method to form good quality, thin epitaxial CoSi2 films on most Si surfaces. We have performed an in-situ study of the OME of CoSi2, on the Si (001) surface. Our work was carried out with our specially modified ultra-high vacuum transmission electron microscope (UHV TEM) SHEBA (Surface High Energy Electron Beam Apparatus). With SHEBA we were able to monitor the diffraction pattern and therefore the phase formation throughout the anneal. Our results confirm the suppression of intermediate phases during CoSi2 formation in the OME process. We also see a difference in the as deposited Co film when the oxide coated silicon surface is used rather than a clean substrate. From combined imaging and diffraction studies we will shed some light on the mechanism behind the success of OME.


2021 ◽  
Vol 546 ◽  
pp. 149136
Author(s):  
O.V. Molodtsova ◽  
I.M. Aristova ◽  
D.V. Potorochin ◽  
I.I. Khodos ◽  
A.N. Chaika ◽  
...  

2010 ◽  
Vol 518 (16) ◽  
pp. 4688-4691 ◽  
Author(s):  
Krzysztof Kolanek ◽  
Massimo Tallarida ◽  
Konstantin Karavaev ◽  
Dieter Schmeisser

1989 ◽  
Vol 158 ◽  
Author(s):  
M. Taneya ◽  
Y. Sugimoto ◽  
H. Hidaka ◽  
K. Akita

ABSTRACTIn-situ patterning of AlxGa1-xAs (0≦x≦0.7) using a electron-beam (EB) and chlorine gas (Cl2) and the application to “In-Situ EB Lithography” are investigated. In this patterning method, an ultra-thin GaAs oxide is utilized as a resist film. The oxide resist prevents C12 gas etching of the underlying material and can be also patterned by an EB irradiation under a C12 pressure, which brings about selective etching of GaAs/AlGaAs layers. Etch rates of AlxGa1-xAs (0<x≦0.7) are 20-30 nm/min, which is almost equal to that of GaAs (20 nm/min). Using this technique of EB-induced patterning, a novel concept “In-Situ EB Lithography” is proposed, where the whole processes for EB lithography are successively conducted in a ultra-high vacuum multi-chamber system. An overgrown layer on a GaAs surface patterned by this “In-Situ EB Lithography” shows a good morphology.


Author(s):  
L. E. Murr ◽  
G. Wong

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.


Author(s):  
J. E. O'Neal ◽  
J. J. Bellina ◽  
B. B. Rath

Thin films of the bcc metals vanadium, niobium and tantalum were epitaxially grown on (0001) and sapphire substrates. Prior to deposition, the mechanical polishing damage on the substrates was removed by an in-situ etch. The metal films were deposited by electron-beam evaporation in ultra-high vacuum. The substrates were heated by thermal contact with an electron-bombarded backing plate. The deposition parameters are summarized in Table 1.The films were replicated and examined by electron microscopy and their crystallographic orientation and texture were determined by reflection electron diffraction. Verneuil-grown and Czochralskigrown sapphire substrates of both orientations were employed for each evaporation. The orientation of the metal deposit was not affected by either increasing the density of sub-grain boundaries by about a factor of ten or decreasing the deposition rate by a factor of two. The results on growth epitaxy are summarized in Tables 2 and 3.


Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.


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