Silicide formation in cobalt/amorphous silicon, amorphous Co-Si and bias-induced Co-Si films

Jae Yeob Shim, Sang Wook Park, Hong Koo Baik

Research output: Contribution to journalArticle

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Abstract

The silicide formation in cobalt/amorphous silicon multilayer films, amorphous cobalt-silicon films, and bias-induced cobalt-silicon films has been examined by differential scanning calorimetry, X-ray diffraction, and transmission electron microscopy. For amorphous cobalt-silicon and bias-induced cobalt-silicon films, Co2Si forms as a first silicide phase, followed by the formation of CoSi and CoSi2. For a Co/a-Si multilayer film with the atomic concentration ratio of the cobalt to silicon layer being 1:2, CoSi is found to be formed as the first silicide phase. It is confirmed that CoSi, Co2Si, CoSi, and CoSi2 form sequentially as the scanning temperature increases. The observed phase sequence is analyzed by the effective heat of formation. A structure factor in addition to the effective heat of formation is used to explain the difference in the formation of the first phase between cobalt/amorphous silicon multilayer films, amorphous cobalt-silicon alloy films, and bias-induced cobalt-silicon films. For the case of bias-induced cobalt-silicon films prepared at various substrate temperatures and bias conditions, the phase sequence and crystallinity of cobalt silicide have a stronger dependence on the substrate bias voltage than on the substrate temperature due to the effects of collisional cascade mixing, in-situ cleaning, and an increase in the number of nucleation sites by ion bombardment on the growing surface. Also, bias-induced epitaxial CoSi2 layer is grown at 200 °C, a much lower temperature than molecular beam epitaxy. In order to quantitatively explain low-temperature epitaxial growth of the CoSi2 layer, the Ar ion energy transferred to Co and Si atoms and the resputtering yield as a function of substrate bias voltage are calculated.

Original languageEnglish
Pages (from-to)31-39
Number of pages9
JournalThin Solid Films
Volume292
Issue number1-2
DOIs
Publication statusPublished - 1997 Jan 5

Fingerprint

Cobalt
Amorphous silicon
amorphous silicon
cobalt
Silicon
silicon films
Multilayer films
heat of formation
Substrates
Bias voltage
Temperature
cobalt alloys
Cobalt alloys
Silicon alloys
silicon alloys
scanning
Epitaxial layers
electric potential
silicon
Ion bombardment

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

Cite this

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title = "Silicide formation in cobalt/amorphous silicon, amorphous Co-Si and bias-induced Co-Si films",
abstract = "The silicide formation in cobalt/amorphous silicon multilayer films, amorphous cobalt-silicon films, and bias-induced cobalt-silicon films has been examined by differential scanning calorimetry, X-ray diffraction, and transmission electron microscopy. For amorphous cobalt-silicon and bias-induced cobalt-silicon films, Co2Si forms as a first silicide phase, followed by the formation of CoSi and CoSi2. For a Co/a-Si multilayer film with the atomic concentration ratio of the cobalt to silicon layer being 1:2, CoSi is found to be formed as the first silicide phase. It is confirmed that CoSi, Co2Si, CoSi, and CoSi2 form sequentially as the scanning temperature increases. The observed phase sequence is analyzed by the effective heat of formation. A structure factor in addition to the effective heat of formation is used to explain the difference in the formation of the first phase between cobalt/amorphous silicon multilayer films, amorphous cobalt-silicon alloy films, and bias-induced cobalt-silicon films. For the case of bias-induced cobalt-silicon films prepared at various substrate temperatures and bias conditions, the phase sequence and crystallinity of cobalt silicide have a stronger dependence on the substrate bias voltage than on the substrate temperature due to the effects of collisional cascade mixing, in-situ cleaning, and an increase in the number of nucleation sites by ion bombardment on the growing surface. Also, bias-induced epitaxial CoSi2 layer is grown at 200 °C, a much lower temperature than molecular beam epitaxy. In order to quantitatively explain low-temperature epitaxial growth of the CoSi2 layer, the Ar ion energy transferred to Co and Si atoms and the resputtering yield as a function of substrate bias voltage are calculated.",
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Silicide formation in cobalt/amorphous silicon, amorphous Co-Si and bias-induced Co-Si films. / Shim, Jae Yeob; Park, Sang Wook; Baik, Hong Koo.

In: Thin Solid Films, Vol. 292, No. 1-2, 05.01.1997, p. 31-39.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Silicide formation in cobalt/amorphous silicon, amorphous Co-Si and bias-induced Co-Si films

AU - Shim, Jae Yeob

AU - Park, Sang Wook

AU - Baik, Hong Koo

PY - 1997/1/5

Y1 - 1997/1/5

N2 - The silicide formation in cobalt/amorphous silicon multilayer films, amorphous cobalt-silicon films, and bias-induced cobalt-silicon films has been examined by differential scanning calorimetry, X-ray diffraction, and transmission electron microscopy. For amorphous cobalt-silicon and bias-induced cobalt-silicon films, Co2Si forms as a first silicide phase, followed by the formation of CoSi and CoSi2. For a Co/a-Si multilayer film with the atomic concentration ratio of the cobalt to silicon layer being 1:2, CoSi is found to be formed as the first silicide phase. It is confirmed that CoSi, Co2Si, CoSi, and CoSi2 form sequentially as the scanning temperature increases. The observed phase sequence is analyzed by the effective heat of formation. A structure factor in addition to the effective heat of formation is used to explain the difference in the formation of the first phase between cobalt/amorphous silicon multilayer films, amorphous cobalt-silicon alloy films, and bias-induced cobalt-silicon films. For the case of bias-induced cobalt-silicon films prepared at various substrate temperatures and bias conditions, the phase sequence and crystallinity of cobalt silicide have a stronger dependence on the substrate bias voltage than on the substrate temperature due to the effects of collisional cascade mixing, in-situ cleaning, and an increase in the number of nucleation sites by ion bombardment on the growing surface. Also, bias-induced epitaxial CoSi2 layer is grown at 200 °C, a much lower temperature than molecular beam epitaxy. In order to quantitatively explain low-temperature epitaxial growth of the CoSi2 layer, the Ar ion energy transferred to Co and Si atoms and the resputtering yield as a function of substrate bias voltage are calculated.

AB - The silicide formation in cobalt/amorphous silicon multilayer films, amorphous cobalt-silicon films, and bias-induced cobalt-silicon films has been examined by differential scanning calorimetry, X-ray diffraction, and transmission electron microscopy. For amorphous cobalt-silicon and bias-induced cobalt-silicon films, Co2Si forms as a first silicide phase, followed by the formation of CoSi and CoSi2. For a Co/a-Si multilayer film with the atomic concentration ratio of the cobalt to silicon layer being 1:2, CoSi is found to be formed as the first silicide phase. It is confirmed that CoSi, Co2Si, CoSi, and CoSi2 form sequentially as the scanning temperature increases. The observed phase sequence is analyzed by the effective heat of formation. A structure factor in addition to the effective heat of formation is used to explain the difference in the formation of the first phase between cobalt/amorphous silicon multilayer films, amorphous cobalt-silicon alloy films, and bias-induced cobalt-silicon films. For the case of bias-induced cobalt-silicon films prepared at various substrate temperatures and bias conditions, the phase sequence and crystallinity of cobalt silicide have a stronger dependence on the substrate bias voltage than on the substrate temperature due to the effects of collisional cascade mixing, in-situ cleaning, and an increase in the number of nucleation sites by ion bombardment on the growing surface. Also, bias-induced epitaxial CoSi2 layer is grown at 200 °C, a much lower temperature than molecular beam epitaxy. In order to quantitatively explain low-temperature epitaxial growth of the CoSi2 layer, the Ar ion energy transferred to Co and Si atoms and the resputtering yield as a function of substrate bias voltage are calculated.

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