Investigation of hydrogen inductively coupled plasma treatment effect for Ge0.938Sn0.062/Ge/Si film using photoreflectance spectroscopy

Hyun Jun Jo, Jong Su Kim, Mee Yi Ryu, Yung Kee Yeo, John Kouvetakis

Research output: Research - peer-reviewArticle

Abstract

Temperature-dependent photoreflectance (PR) measurements for Ge0.938Sn0.062/Ge/Si films treated with a hydrogen inductively coupled plasma (H2-ICP) have been performed. The Ge0.938Sn0.062 film is grown on Ge-buffered Si substrate by ultra-high vacuum chemical vapor deposition method, and the H2-ICP treatment was carried out for 5 min for the Ge0.938Sn0.062 epitaxial layer. The high-resolution X-ray diffraction results show that the compressive strain of the Ge0.938Sn0.062 layer decreases and the tensile strain of the Ge buffer layer increases after H2-ICP treatment. The PR spectrum of as-grown Ge0.938Sn0.062/Ge/Si film at 300 K consists of three signals at 0.603, 0.782 and 0.814 eV, which are assigned to the direct transitions from conduction Γ valley to the valence bands related to the surface of Ge0.938Sn0.062, the Ge/Si and GeSn/Ge interfaces, respectively. After H2-ICP treatment, two PR signals of 0.604 and 0.781 eV were obtained at 300 K and they are attributed to the direct transition energies of the Ge0.938Sn0.062 and the Ge buffer layer, respectively. As temperature decreases, new weak PR signals appear in the lower energy regions of both PR signals from the H2-ICP treated GeSn and Ge layers at 210 K and 130 K, respectively, due to the increase of tensile strain in Ge layer while no new signal appears for the as-grown sample. The PR spectrum of the H2-ICP treated sample at 10 K shows four signals, and these signals are assigned to the surface of GeSn and GeSn at the interface between GeSn and Ge buffer layers, the Ge at the interface between GeSn and Ge buffer layers, and the Ge at the interface between Ge buffer layer and Si substrate, respectively. These PR results indicate that H2-ICP treatment significantly affects the strain and defects near the interface between GeSn and Ge layers, and thus optical properties of GeSn layer are also altered by H2-ICP treatment.

LanguageEnglish (US)
Pages345-350
Number of pages6
JournalThin Solid Films
Volume645
DOIs
StatePublished - Jan 1 2018

Fingerprint

Inductively coupled plasma
Buffer layers
Hydrogen
Spectroscopy
hydrogen
spectroscopy
buffers
Tensile strain
Substrates
Temperature
Epitaxial layers
Ultrahigh vacuum
Electron transitions
Valence bands
Chemical vapor deposition
Optical properties
X ray diffraction
Defects
K 130
temperature

Keywords

  • Germanium tin
  • Photoreflectance
  • Strain

ASJC Scopus subject areas

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

Cite this

Investigation of hydrogen inductively coupled plasma treatment effect for Ge0.938Sn0.062/Ge/Si film using photoreflectance spectroscopy. / Jo, Hyun Jun; Kim, Jong Su; Ryu, Mee Yi; Yeo, Yung Kee; Kouvetakis, John.

In: Thin Solid Films, Vol. 645, 01.01.2018, p. 345-350.

Research output: Research - peer-reviewArticle

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abstract = "Temperature-dependent photoreflectance (PR) measurements for Ge0.938Sn0.062/Ge/Si films treated with a hydrogen inductively coupled plasma (H2-ICP) have been performed. The Ge0.938Sn0.062 film is grown on Ge-buffered Si substrate by ultra-high vacuum chemical vapor deposition method, and the H2-ICP treatment was carried out for 5 min for the Ge0.938Sn0.062 epitaxial layer. The high-resolution X-ray diffraction results show that the compressive strain of the Ge0.938Sn0.062 layer decreases and the tensile strain of the Ge buffer layer increases after H2-ICP treatment. The PR spectrum of as-grown Ge0.938Sn0.062/Ge/Si film at 300 K consists of three signals at 0.603, 0.782 and 0.814 eV, which are assigned to the direct transitions from conduction Γ valley to the valence bands related to the surface of Ge0.938Sn0.062, the Ge/Si and GeSn/Ge interfaces, respectively. After H2-ICP treatment, two PR signals of 0.604 and 0.781 eV were obtained at 300 K and they are attributed to the direct transition energies of the Ge0.938Sn0.062 and the Ge buffer layer, respectively. As temperature decreases, new weak PR signals appear in the lower energy regions of both PR signals from the H2-ICP treated GeSn and Ge layers at 210 K and 130 K, respectively, due to the increase of tensile strain in Ge layer while no new signal appears for the as-grown sample. The PR spectrum of the H2-ICP treated sample at 10 K shows four signals, and these signals are assigned to the surface of GeSn and GeSn at the interface between GeSn and Ge buffer layers, the Ge at the interface between GeSn and Ge buffer layers, and the Ge at the interface between Ge buffer layer and Si substrate, respectively. These PR results indicate that H2-ICP treatment significantly affects the strain and defects near the interface between GeSn and Ge layers, and thus optical properties of GeSn layer are also altered by H2-ICP treatment.",
keywords = "Germanium tin, Photoreflectance, Strain",
author = "Jo, {Hyun Jun} and Kim, {Jong Su} and Ryu, {Mee Yi} and Yeo, {Yung Kee} and John Kouvetakis",
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AU - Jo,Hyun Jun

AU - Kim,Jong Su

AU - Ryu,Mee Yi

AU - Yeo,Yung Kee

AU - Kouvetakis,John

PY - 2018/1/1

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N2 - Temperature-dependent photoreflectance (PR) measurements for Ge0.938Sn0.062/Ge/Si films treated with a hydrogen inductively coupled plasma (H2-ICP) have been performed. The Ge0.938Sn0.062 film is grown on Ge-buffered Si substrate by ultra-high vacuum chemical vapor deposition method, and the H2-ICP treatment was carried out for 5 min for the Ge0.938Sn0.062 epitaxial layer. The high-resolution X-ray diffraction results show that the compressive strain of the Ge0.938Sn0.062 layer decreases and the tensile strain of the Ge buffer layer increases after H2-ICP treatment. The PR spectrum of as-grown Ge0.938Sn0.062/Ge/Si film at 300 K consists of three signals at 0.603, 0.782 and 0.814 eV, which are assigned to the direct transitions from conduction Γ valley to the valence bands related to the surface of Ge0.938Sn0.062, the Ge/Si and GeSn/Ge interfaces, respectively. After H2-ICP treatment, two PR signals of 0.604 and 0.781 eV were obtained at 300 K and they are attributed to the direct transition energies of the Ge0.938Sn0.062 and the Ge buffer layer, respectively. As temperature decreases, new weak PR signals appear in the lower energy regions of both PR signals from the H2-ICP treated GeSn and Ge layers at 210 K and 130 K, respectively, due to the increase of tensile strain in Ge layer while no new signal appears for the as-grown sample. The PR spectrum of the H2-ICP treated sample at 10 K shows four signals, and these signals are assigned to the surface of GeSn and GeSn at the interface between GeSn and Ge buffer layers, the Ge at the interface between GeSn and Ge buffer layers, and the Ge at the interface between Ge buffer layer and Si substrate, respectively. These PR results indicate that H2-ICP treatment significantly affects the strain and defects near the interface between GeSn and Ge layers, and thus optical properties of GeSn layer are also altered by H2-ICP treatment.

AB - Temperature-dependent photoreflectance (PR) measurements for Ge0.938Sn0.062/Ge/Si films treated with a hydrogen inductively coupled plasma (H2-ICP) have been performed. The Ge0.938Sn0.062 film is grown on Ge-buffered Si substrate by ultra-high vacuum chemical vapor deposition method, and the H2-ICP treatment was carried out for 5 min for the Ge0.938Sn0.062 epitaxial layer. The high-resolution X-ray diffraction results show that the compressive strain of the Ge0.938Sn0.062 layer decreases and the tensile strain of the Ge buffer layer increases after H2-ICP treatment. The PR spectrum of as-grown Ge0.938Sn0.062/Ge/Si film at 300 K consists of three signals at 0.603, 0.782 and 0.814 eV, which are assigned to the direct transitions from conduction Γ valley to the valence bands related to the surface of Ge0.938Sn0.062, the Ge/Si and GeSn/Ge interfaces, respectively. After H2-ICP treatment, two PR signals of 0.604 and 0.781 eV were obtained at 300 K and they are attributed to the direct transition energies of the Ge0.938Sn0.062 and the Ge buffer layer, respectively. As temperature decreases, new weak PR signals appear in the lower energy regions of both PR signals from the H2-ICP treated GeSn and Ge layers at 210 K and 130 K, respectively, due to the increase of tensile strain in Ge layer while no new signal appears for the as-grown sample. The PR spectrum of the H2-ICP treated sample at 10 K shows four signals, and these signals are assigned to the surface of GeSn and GeSn at the interface between GeSn and Ge buffer layers, the Ge at the interface between GeSn and Ge buffer layers, and the Ge at the interface between Ge buffer layer and Si substrate, respectively. These PR results indicate that H2-ICP treatment significantly affects the strain and defects near the interface between GeSn and Ge layers, and thus optical properties of GeSn layer are also altered by H2-ICP treatment.

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