Grain Growth in Titanium Silicide Films During the Formation Reaction

1990 ◽  
Vol 202 ◽  
Author(s):  
Yunji L. Corcoran ◽  
Alexander H. King ◽  
Nimal deLanerolle ◽  
Bonggi Kim ◽  
John Berg
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Cross Section ◽  
Titanium Silicide ◽  
Silicon Substrates ◽  
Experimental Conditions ◽  
Silicide Layer ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Relationship Of

ABSTRACTTitanium films of 0.5 µm thickness were sputter deposited on silicon substrates. After rapid thermal annealing at temperatures ranging from 600°C to 850°C for times up to 45 seconds in nitrogen, transmission electron microscope (TEM) cross section specimens were made from the wafers. Grain sizes of the resulting titanium disilicide were measured from TEM cross section micrographs. The results show that C49-TiSi2 has a different grain growth rate than C54-TiSi2- Under our experimental conditions, C54-TiSi2 has a much higher growth rate. Titanium silicide on arsenic implanted silicon substrates shows a lower grain growth rate than that on unimplanted substrates under the same conditions. The thickness of the silicide layer was also measured for each specimen. The relationship of thickness and grain size will be discussed.

Integrated Processinyg of Silicided Shallow Junctions using Rapid Thermal Annealing Prior to Dopant Activation

1989 ◽  
Vol 146 ◽  
Author(s):  
Leonard Rubin ◽  
Nicole Herbots ◽  
JoAnne Gutierrez ◽  
David Hoffman ◽  
Di Ma
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Titanium Silicide ◽  
Silicon Substrates ◽  
Sheet Resistivity ◽  
Furnace Annealing ◽  
Dopant Activation ◽  
Silicide Layer ◽  
Low Leakage ◽  
Sputter Deposited

ABSTRACTA method for producing shallow silicided diodes for MOS devices (with junction depths of about 0.1 µm), by implanting after forming the silicide layer was investigated. The key to this integrated process is the use of rapid thermal annealing (RTA) to activate the dopants in the silicon, so that there is very little thermal broadening of the implant distribution. Self-aligned titanium silicide (TiSi2) films with thicknesses ranging from 40 to 80 nm were grown by RTA of sputter deposited titanium films on silicon substrates. After forming the TiSi2, arsenic and boron were implanted. A second RTA step was used after implantation to activate these dopants. It was found that implanting either dopant caused a sharp increase in the sheet resistivity of the TiSi2. The resistivity can be easily restored to its original value (about 18 µΩ-cm) by a post implant RTA anneal. RBS analysis showed that arsenic diffuses rapidly in the TiSi2 during RTA at temperatures as low as 600°C. SIMS data indicated that boron was not mobile up to temperatures of 900°C, possibly because it forms a compound with the titanium which precipitates in the TiSi 2. Coalescence of TiSi2 occurs during post implant furnace annealing, leading to an increase in the sheet resistivity. The amount of coalescence depends on the film thickness, but not on whether or not the film had been subject to implantation. Spreading resistance profiling data showed that both arsenic and boron diffused into the TiSi2 during furnace annealing, reducing the surface concentrations of dopant at the TiSi2/Si interface. Both N+/P and P+/N diodes formed by this technique exhibited low leakage currents after the second RTA anneal. This is attributed to removal of the implant damage by the RTA. In summary, the second RTA serves the dual purpose of removing implant damage in the TiSi2 and creating the shallow junction by dopant activation.

Magnetic Properties and Crystallography of Selected Co/Pt Multilayers with Rare-Earth Additions

1993 ◽  
Vol 313 ◽  
Author(s):  
G.A. Bertero ◽  
R.L. White ◽  
R. Sinclair
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Cross Section ◽  
Uniaxial Anisotropy ◽  
Amorphous Film ◽  
Perpendicular Anisotropy ◽  
Grain Sizes ◽  
Transmission Electron ◽  
Rare Earth Additions ◽  
Sputter Deposited

ABSTRACTWe have sputter-deposited a series of Pt/CO Multilayers with differing amounts of rare-earth (RE) in an effort to improve the uniaxial perpendicular anisotropy in these structures. The present work investigates the influence on the magnetic properties of Tb and Ho incorporated both at the interfaces of Pt/CO Multilayers and into the Co layers. The uniaxial anisotropy improved significantly only for those multilayers that showed poor perpendicular anisotropy in the undoped state, in particular, those with large (∼30 Å) bilayer periods. High resolution transmission electron microscopy was used to study these multilayers in cross-section. The Multilayer structures present strong [111] texture with grain sizes ranging from 200 to 600 Å. It is found that the RE does not produce a significant change in the growth texture of the multilayers until a critical amount is introduced beyond which the multilayer structure amorphizes resulting in a compositionally modulated amorphous film.

The Effects of Nucleation and Growth on Epitaxy in the CoSi2/Si System

1981 ◽  
Vol 10 ◽  
Author(s):  
J. M. Gibson ◽  
J. C. Bean ◽  
J. M. Poate ◽  
R. T. Tung
Keyword(s):  
Cross Section ◽  
Defect Structure ◽  
Ultrahigh Vacuum ◽  
Nucleation And Growth ◽  
Silicon Substrates ◽  
Pinning Mechanism ◽  
Preparation Conditions ◽  
Transmission Electron ◽  
Silicide Growth

The epitaxial perfection and microstructure in thin CoSi2 (111) (and NiSi2) films on silicon has been examined using transmission electron microscopy, including high resolution cross section techniques. We find that, under ultrahigh vacuum preparation conditions only, genuine single-crystal epitaxy can occur for bothreacted and codeposited CoSi2 films. A unique interfacial defect structure is associated with this epitaxy, in which the silicide films are rotated through 180° about (111) with respect to the silicon substrates. Under less than perfectly clean conditions epitaxial perfection is never obtained for CoSi2. Moreover such perfection has never been attained under any conditions for NiSi2 on Si(111). By studying the evolution of epitaxy and defect structure in thin and thick films we have proposed a model to explain the unique quality of ultrahigh vacuum CoSi2 films. The model invokes a defect pinning mechanism to explain the dominance of the 180°-rotated epitaxy during silicide growth.

Doping Influence on TiSi2 C49-C54 Phase Conversion Kinetics by Micro-Raman Spectroscopy

1998 ◽  
Vol 514 ◽  
Author(s):  
F. Meinardi ◽  
S. Quilici ◽  
L. Moro ◽  
G. Queirolo ◽  
A. Sabbadini
Keyword(s):  
Phase Transition ◽  
Activation Energy ◽  
Growth Rate ◽  
Polycrystalline Silicon ◽  
Titanium Silicide ◽  
Silicon Substrates ◽  
Nucleation Center ◽  
Phase Conversion ◽  
Micro Raman Spectroscopy ◽  
Center Density

ABSTRACTMicroRaman measurements on titanium silicide films grown on single-crystal and polycrystalline silicon substrates doped with As, BF2 and P have been performed. The data collected on patterns of different areas and shapes, but comparable doping level show that the doping has negligible effects both on C54 nucleation center density and on activation energy for the C49/C54 phase transition. On the contrary, substrate strongly affects the C54 growth rate, ruling the ability of the C54 phase to propagate after the nucleation.

Nucleation and Abnormal Grain Growth of Alpha-A12O3 in Gamma-Alumina Matrix

1991 ◽  
Vol 230 ◽  
Author(s):  
T. C. Chou ◽  
T. G. Nieh
Keyword(s):  
Grain Growth ◽  
Boundary Migration ◽  
Abnormal Grain Growth ◽  
Alumina Matrix ◽  
Orientation Relationships ◽  
Nucleation Kinetics ◽  
Alumina Films ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Sputter Deposited

AbstractThe microstructures of reactive sputter-deposited alumina films have been studied by transmission electron microscopy. The as-deposited films contained γ-A12O3 phase in an amorphous alumina matrix. Annealing of the films at 1200° C for 2 h resulted in nucleation and concurrent anomalous grain growth of α-A12O3 in a polycrystaUine γ-Al2O3 matrix which exhibited a layered microstructure and was strongly textured along [001]. The grain sizes of α-A12O3 varied from 3 to 20 μm, while the average grain size of γ-A12O3 was only about 50 nm. It appears that the nucleation kinetics of a-A12O3 was slow. As a result, the abnormal grain growth of α-A12O3 proceeded by consuming surrounding γ-Al2O3 grains. An atomic model is presented to explain the origin of layered structure in γ-A12O3. The nucleation mechanism of a-A12O3 in γ-alumina matrix is suggested. Orientation relationships between γ- and α-A12O3 are reported. The anomalous grain growth of α- A12O3 is discussed in terms of γ/α interface boundary migration.

scholarly journals An in situ transmission electron microscope investigation into grain growth and ordering of sputter-deposited nanocrystalline Ni3Al thin films

2002 ◽  
Vol 17 (8) ◽  
pp. 2085-2094 ◽  
Author(s):  
H. P. Ng ◽  
A. H. W. Ngan
Keyword(s):  
Electron Microscope ◽  
Grain Growth ◽  
Transmission Electron Microscope ◽  
Growth Kinetics ◽  
Abnormal Grain Growth ◽  
Face Centered Cubic ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Grain Growth Kinetics

The grain growth kinetics and ordering behavior of direct-current magnetron sputter-deposited Ni75at.%Al25at.% alloy films were investigated using in situ isothermal annealing in a transmission electron microscope. Both normal and abnormal grain growth modes were observed. The normal grain growth kinetics under isothermal heating from 300 to 700 °C were found to comply with the Burke law d = K/dn−1, where d is grain size and K and n are constants with respect to time. The grain boundary mobility parameter K was found to obey an Arrehnius rate law with an apparent activation energy of 1.6 eV, and n was found to increase gradually from 5.2 at 300 °C to 8.7 at 700 °C. Abnormal grain growth occurred at 500 °C or higher, and grain coalescence was identified as an important operative mechanism. It was also observed that the initially as-deposited state of the films was crystalline with a disordered face-centered-cubic structure, but ordering into the equilibrium L12 intermetallic structure followed from annealing at temperatures above approximately 500 °C.

Relationship Between The Void And Hillock Formation And The Grain Growth In Thin Aluminum Films

1996 ◽  
Vol 428 ◽  
Author(s):  
O. V. Kononenko ◽  
V. N. Matveev
Keyword(s):  
Stress Relaxation ◽  
Grain Growth ◽  
The Self ◽  
Diffusion Creep ◽  
Silicon Substrates ◽  
Aluminum Films ◽  
Bias Stress ◽  
Transmission Electron ◽  
Thin Aluminum ◽  
Hillock Formation

AbstractVoid and hillock formation during annealing was studied depending on the deposition conditions. Aluminum films were deposited onto oxidized silicon substrates by the self-ion assisted technique. The bias 0 or 6 kV was applied to the substrate during deposition. The films were then annealed in vacuum for 1 hour in the temperature range from 1500 to 550°C. The structure of the films was investigated by transmission electron microscopy.It was found that recrystallization and void and hillock formation in the films depend on the bias during deposition. Normal grain growth occurred in the films deposited without bias. Abnormal grain growth was observed in the 6 kV-films. It was also found that the mechanism of stress relaxation during thermal cycling depends on the self-ion bombardment. In the films prepared without bias, stress relaxation proceeds by diffusion creep. In the films deposited at the 6 kV bias, stress relaxation proceeds by plastic deformation.

Structural and Phase Transformations in Thin Film Ti-Aluminides and Ti/Al Multilayers

1996 ◽  
Vol 434 ◽  
Author(s):  
R. Banerjee ◽  
S. Swaminathan ◽  
R. Wheeler ◽  
H. L. Fraser
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Layer Thickness ◽  
High Resolution Electron Microscopy ◽  
Silicon Substrates ◽  
Two Phase ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Sputter Deposited

AbstractMultilayered Ti/Al thin films (with nominally equal layer thickness of Ti and Al) have been sputter deposited on oxidized silicon substrates at room temperature. Transmission electron microscopy (TEM) and high resolution electron microscopy have been used to characterize the structure of these multilayers as a function of the layer thickness. Ti changed from an hcp to an fcc and back to an hcp structure on reduction of the layer thickness. Al too changed from an fcc to an hcp structure at a layer thickness of 2.5 nm. The observed structural transitions have been explained on the basis of the Redfield-Zangwill model. Subsequently Ti-aluminide thin films were deposited using a γ-TiAl target. These films were found to be amorphous in the as-deposited condition with crystallites of α-Ti(Al) embedded in the amorphous matrix. On annealing under a protective Ar atmosphere at a temperature of 550 °C, the Ti-aluminide film crystallized into a nanocrystalline two phase microstructure consisting of γ-TiAl and α2-Ti3Al. The crystallization of the aluminide film has been investigated in detail by in-situ annealing experiments on a hot stage in the TEM. The results of this investigation have been discussed in this paper.

A Study of Grain Growth in Ion Irradiated Co-Cr Alloy Films

1987 ◽  
Vol 93 ◽  
Author(s):  
J. Li ◽  
B. X. Liu ◽  
H. D. Li
Keyword(s):  
Growth Rate ◽  
Grain Size ◽  
Grain Growth ◽  
Ion Irradiation ◽  
Alloy Films ◽  
Transmission Electron ◽  
Wide Range ◽  
Before And After ◽  
Bcc Structure ◽  
20 Nm

ABSTRACTExperiments concerning the behavior of grain size in Co80Cr20 alloy thin films upon ion irradiation were conducted. The alloy films of 80 nm thick were prepared by magnetron sputtering on cleaved NaCl crystal substrates, and then irradiated by 300 keV argon or xenon ions to a wide range of doses. The irradiated samples, before and after annealing, were examined by transmission electron microscope (TEM). It was found that the initial grain size with the dimension of 20 nm remained unchanged when the dose was less than 1×1016Ar/cm2, but rapidly reduced to the scale of 5 nm at a dose of 5×1016Ar/cm2. It is thought that this is due to a polymorphic transformation of an HCP to a BCC structure in the alloy films. After 30 min. anneals at 200° C, it was observed that the grain growth rate was a function of ion dose, and that there exists a critical fluence yielding a maximum grain growth rate. The possible mechanisms for the observations in this study are discussed.

Invariance of CDST in the Turbulent Wake of Bluff Bodies

2005 ◽  
Author(s):  
J. C. Hu ◽  
Y. Zhou ◽  
J. F. Huang
Keyword(s):  
Drag Coefficient ◽  
Cross Section ◽  
Cross Sections ◽  
Turbulent Wake ◽  
Bluff Bodies ◽  
Square Cylinder ◽  
Experimental Conditions ◽  
Freestream Velocity ◽  
Relationship Of ◽  
Work Done

The inter-relationship of drag coefficient Cd and Strouhal number St in a turbulent wake was experimentally investigated for ten cylinders of the same characteristic height d but of different cross-sections at Re = 2600 and 6000, based on the freestream velocity U∞ and d. It is found that, although Cd and St depend strongly on the geometric cross-section of the cylinder, the product of CdSt is invariant, about 0.25, under present experimental conditions. This invariance of CdSt is further confirmed with respect to Re and angle of attack of a square cylinder based on a collection of data in the literature. It is further found that CdSt is actually the ratio of the dimensionless work done upon the fluid by the cylinder to the dimensionless wavelength.

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