Growth of intermediate phases in Co/Si diffusion couples: Bulk versus thin‐film studies

ABSTRACTBulk diffusion couples of Co/Si were annealed at 800, 900, 1000, 1050 and 1100°C for periods ranging from 24 hours to one month. Growth rates of the intermediate phases, Co2Si, CoSi and CoSi2, as well as the composition profiles across the couples were determined by optical microscopy and electron probe microanalysis (EPMA). Using the solution to the multiphase binary diffusion equations and the experimental data, the interdiffusion coefficients for Co2Si, CoSi and CoSi2 are obtained as a function of temperature. The activation energies obtained are 140, 160 and 190 KJ/mole for Co2Si, CoSi and CoSi2, respectively. The generally small interdiffusion coefficient of CoSi2 and its high activation energy cause the growth rate of CoSi2 to be extremely small at low temperatures.The interdiffusion coefficients for Co2Si, CoSi and CoSi2 at 545°C are obtained by extrapolation of the high-temperatures data. Using these data and solving numerically the diffusion equations with the appropriate boundary conditions, the growth of Co2Si, CoSi and CoSi2 is calculated as a function of time. The calculated results are in good agreement with the experimental data reported in the literature. This study demonstrates clearly that the initial absence of the CoSi2 phase is due to diffusion-controlled rather than nucleation-controlled kinetics. This phenomenon may be quite common in many thin-fiflm metal/Si couples.

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Reactions between palladium and gallium arsenide: Bulk versus thin-film studies

Journal of Materials Research ◽

10.1557/jmr.1988.0148 ◽

1988 ◽

Vol 3 (1) ◽

pp. 148-163 ◽

Cited By ~ 69

Author(s):

J. -C. Lin ◽

K. -C. Hsieh ◽

K. J. Schulz ◽

Y. A. Chang

Keyword(s):

Thin Film ◽

Phase Formation ◽

Ternary Phase ◽

Film Studies ◽

Bulk Diffusion ◽

Diffusion Path ◽

Solution Phase ◽

Stable Configuration ◽

Diffusion Couples ◽

Initial Formation

Reactions between Pd and GaAs have been studied using bulk-diffusion couples of Pd (∼0.6 mm thick) /GaAs and thin-film Pd (50 and 160 nm)/GaAs samples. The sequence of phase formation at 600°C between bulk Pd and GaAs was established. Initial formation of the solution phase μ and the ternary phase T does not represent the stable configuration. The stable configuration is GaAs |∊|Λ|γ|ν|Pd and is termed the diffusion path between GaAs and Pd. The sequence of phase formation for the bulk-diffusion couples is similar at 500°C. Phase formation for the thin-film Pd/GaAs specimens was studied at 180,220,250,300,350,400,450,600, and 1000°C for various annealing times. The sequence of phase formation obtained from the thin-film experiments is rationalized readily from the known ternary phase equilibria of Ga–Pd–As and the results from the bulk-diffusion couples of Pd/GaAs. The thin-film results reported in the literature are likewise rationalized. The diffusion path concept provides a useful guide in understanding the phase formation in Pd–GaAs interface or any other M-GaAs interface. This information is important in designing a uniform, stable contact for the metallization of GaAs.

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Nb Contacts to GaAs: Thermal Stability and Phase Formation

MRS Proceedings ◽

10.1557/proc-108-455 ◽

1987 ◽

Vol 108 ◽

Cited By ~ 4

Author(s):

Kevin J. Schulz ◽

Xiang-Yun Zheng ◽

Y. Austin Chang

Keyword(s):

Thin Film ◽

Thermal Stability ◽

Film Studies ◽

Bulk Diffusion ◽

Diffusion Path ◽

Diffusion Couples ◽

Compound Formation ◽

The Stability ◽

Binary Compounds ◽

Thermal Stability Of

ABSTRACTThe applicability of Nb as a Schottky barrier on GaAs depends to a large extent on the thermal stability of the contacts. In this study, bulk diffusion couple and phase diagram studies in addition to thin film studies were completed to understand the stability of and the reactions at the Nb/GaAs interface. Nb thin films were deposited onto GaAs substrates by dc magnetron sputtering and were annealed in the temperature range 300 to 1000°C. Analysis was done using plan-TEM and XTEM. The Nb/GaAs interface was found to break down into a series of binary compounds above 500°C. Bulk diffusion couples annealed at 600°C were analyzed using an electron microprobe. The stable sequence of phases formed in the couple, i.e., the diffusion path, was determined and was used to rationalize the observed compound formation in the thin film contact system.

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Reaction couples of ceramic thin films prepared by CVD

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106053 ◽

1988 ◽

Vol 46 ◽

pp. 798-799

Author(s):

D.W. Susnitzky ◽

S.R. Summerfelt ◽

C.B. Carter

Keyword(s):

Thin Film ◽

Vapor Deposition ◽

Chemical Vapor ◽

Deposition Process ◽

Solid State Reactions ◽

Spatial Distributions ◽

Diffusion Couples ◽

Kinetics Studies ◽

Ceramic Thin Films ◽

Initial Stage

Solid-state reactions have traditionally been studied in the form of diffusion couples. This ‘bulk’ approach has been modified, for the specific case of the reaction between NiO and Al2O3, by growing NiAl2O4 (spinel) from electron-transparent Al2O3 TEM foils which had been exposed to NiO vapor at 1415°C. This latter ‘thin-film’ approach has been used to characterize the initial stage of spinel formation and to produce clean phase boundaries since further TEM preparation is not required after the reaction is completed. The present study demonstrates that chemical-vapor deposition (CVD) can be used to deposit NiO particles, with controlled size and spatial distributions, onto Al2O3 TEM specimens. Chemical reactions do not occur during the deposition process, since CVD is a relatively low-temperature technique, and thus the NiO-Al2O3 interface can be characterized. Moreover, a series of annealing treatments can be performed on the same sample which allows both Ni0-NiAl2O4 and NiAl2O4-Al2O3 interfaces to be characterized and which therefore makes this technique amenable to kinetics studies of thin-film reactions.

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Calibration of a fan-shaped beam surface plasmon resonance instrument for quantitative adsorbed thin film studies—No metal film thickness or optical properties required

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2012.09.002 ◽

2013 ◽

Vol 176 ◽

pp. 736-745 ◽

Cited By ~ 7

Author(s):

Antonella Badia ◽

Ching-I Chen ◽

Lana L. Norman

Keyword(s):

Thin Film ◽

Optical Properties ◽

Surface Plasmon Resonance ◽

Film Thickness ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Metal Film ◽

Film Studies ◽

Shaped Beam ◽

Beam Surface

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Ni Silicide Formation on Polycrystalline SiGe and SiGeC Layers

MRS Proceedings ◽

10.1557/proc-745-n4.8 ◽

2002 ◽

Vol 745 ◽

Cited By ~ 2

Author(s):

Erik Haralson ◽

Tobias Jarmar ◽

Johan Seger ◽

Henry H. Radamson ◽

Shi-Li Zhang ◽

...

Keyword(s):

Thin Film ◽

Thermal Processing ◽

Rapid Thermal Processing ◽

Lateral Diffusion ◽

Lateral Growth ◽

Silicide Formation ◽

Diffusion Couples ◽

Planar Configuration ◽

20 Nm

ABSTRACTThe reactions of Ni with polycrystalline Si, Si0.82Ge0.18 and Si0.818Ge0.18C0.002 films in two different configurations during rapid thermal processing were studied. For the usually studied planar configuration with 20 nm thick Ni on 130–290 nm thick Si1-x-yGexCy, NiSi1-xGex(C) forms at 450°C on either Si0.82Ge0.18 or Si0.818Ge0.18C0.002, comparable to NiSi formed on Si. However, the agglomeration of NiSi1-xGex(C) on Si0.818Ge0.18C0.002 occurs at 625°C, about 50°C higher than that of NiSi1-xGex on Si0.82Ge0.18. For thin-film lateral diffusion couples, a 200-nm thick Ni film was in contact with 80–130 nm thick Si1-x-yGexCy through 1–10 μm sized contact openings in a 170 nm thick SiO2 isolation. While the Ni3Si phase was formed for both the Si0.82Ge0.18 and Si0.818Ge0.18C0.002 samples, the presence of 0.2 at.% C caused a slightly slower lateral growth.

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