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Title: Molecular beam deposition of Al{sub 2}O{sub 3} on p-Ge(001)/Ge{sub 0.95}Sn{sub 0.05} heterostructure and impact of a Ge-cap interfacial layer

Abstract

We investigated the molecular beam deposition of Al{sub 2}O{sub 3} on Ge{sub 0.95}Sn{sub 0.05} surface with and without an ultra thin Ge cap layer in between. We first studied the atomic configuration of both Ge{sub 1-x}Sn{sub x} and Ge/Ge{sub 1-x}Sn{sub x} surfaces after deoxidation by reflection high-energy electron diffraction and resulted, respectively, in a c(4x2) and (2x1) surface reconstructions. After in situ deposition of an Al{sub 2}O{sub 3} high-{kappa} gate dielectric we evidenced using time-of-flight secondary ion mass spectroscopy analyses that Sn diffusion was at the origin of high leakage current densities in the Ge{sub 1-x}Sn{sub x}/Al{sub 2}O{sub 3} gate stack. This damage could be avoided by inserting a thin 5-nm-thick Ge cap between the oxide and the Ge{sub 1-x}Sn{sub x} layer. Finally, metal-oxide-semiconductor capacitors on the Ge capped sample showed well-behaved capacitance-voltage (C-V) characteristics with interface trap density (D{sub it}) in the range of 10{sup 12} eV{sup -1} cm{sup -2} in mid gap and higher close to the valence band edge.

Authors:
; ; ; ; ;  [1];  [2]; ; ; ;  [3]
  1. Interuniversity Microelectronics Center (IMEC vzw), Kapeldreef 75, 3001 Leuven (Belgium)
  2. Katholieke Universiteit Leuven, Celestijnelaan 200D, 3001 Leuven (Belgium)
  3. Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)
Publication Date:
OSTI Identifier:
21518431
Resource Type:
Journal Article
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 98; Journal Issue: 19; Other Information: DOI: 10.1063/1.3589992; (c) 2011 American Institute of Physics; Journal ID: ISSN 0003-6951
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM OXIDES; CAPACITANCE; CURRENT DENSITY; DEPOSITION; DIELECTRIC MATERIALS; DIFFUSION; ELECTRON DIFFRACTION; GERMANIUM; HETEROJUNCTIONS; ION MICROPROBE ANALYSIS; LAYERS; LEAKAGE CURRENT; MASS SPECTRA; MASS SPECTROSCOPY; MOLECULAR BEAM EPITAXY; OXIDATION; SEMICONDUCTOR MATERIALS; TIME-OF-FLIGHT METHOD; TIN ADDITIONS; TRAPS; ALLOYS; ALUMINIUM COMPOUNDS; CHALCOGENIDES; CHEMICAL ANALYSIS; CHEMICAL REACTIONS; COHERENT SCATTERING; CRYSTAL GROWTH METHODS; CURRENTS; DIFFRACTION; ELECTRIC CURRENTS; ELECTRICAL PROPERTIES; ELEMENTS; EPITAXY; MATERIALS; METALS; MICROANALYSIS; NONDESTRUCTIVE ANALYSIS; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SCATTERING; SEMICONDUCTOR JUNCTIONS; SPECTRA; SPECTROSCOPY; TIN ALLOYS

Citation Formats

Merckling, C, Franquet, A, Vincent, B, Vandervorst, W, Loo, R, Caymax, M, Sun, X, Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520-8284, Shimura, Y, Takeuchi, S, Nakatsuka, O, and Zaima, S. Molecular beam deposition of Al{sub 2}O{sub 3} on p-Ge(001)/Ge{sub 0.95}Sn{sub 0.05} heterostructure and impact of a Ge-cap interfacial layer. United States: N. p., 2011. Web. doi:10.1063/1.3589992.
Merckling, C, Franquet, A, Vincent, B, Vandervorst, W, Loo, R, Caymax, M, Sun, X, Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520-8284, Shimura, Y, Takeuchi, S, Nakatsuka, O, & Zaima, S. Molecular beam deposition of Al{sub 2}O{sub 3} on p-Ge(001)/Ge{sub 0.95}Sn{sub 0.05} heterostructure and impact of a Ge-cap interfacial layer. United States. https://doi.org/10.1063/1.3589992
Merckling, C, Franquet, A, Vincent, B, Vandervorst, W, Loo, R, Caymax, M, Sun, X, Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520-8284, Shimura, Y, Takeuchi, S, Nakatsuka, O, and Zaima, S. 2011. "Molecular beam deposition of Al{sub 2}O{sub 3} on p-Ge(001)/Ge{sub 0.95}Sn{sub 0.05} heterostructure and impact of a Ge-cap interfacial layer". United States. https://doi.org/10.1063/1.3589992.
@article{osti_21518431,
title = {Molecular beam deposition of Al{sub 2}O{sub 3} on p-Ge(001)/Ge{sub 0.95}Sn{sub 0.05} heterostructure and impact of a Ge-cap interfacial layer},
author = {Merckling, C and Franquet, A and Vincent, B and Vandervorst, W and Loo, R and Caymax, M and Sun, X and Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520-8284 and Shimura, Y and Takeuchi, S and Nakatsuka, O and Zaima, S},
abstractNote = {We investigated the molecular beam deposition of Al{sub 2}O{sub 3} on Ge{sub 0.95}Sn{sub 0.05} surface with and without an ultra thin Ge cap layer in between. We first studied the atomic configuration of both Ge{sub 1-x}Sn{sub x} and Ge/Ge{sub 1-x}Sn{sub x} surfaces after deoxidation by reflection high-energy electron diffraction and resulted, respectively, in a c(4x2) and (2x1) surface reconstructions. After in situ deposition of an Al{sub 2}O{sub 3} high-{kappa} gate dielectric we evidenced using time-of-flight secondary ion mass spectroscopy analyses that Sn diffusion was at the origin of high leakage current densities in the Ge{sub 1-x}Sn{sub x}/Al{sub 2}O{sub 3} gate stack. This damage could be avoided by inserting a thin 5-nm-thick Ge cap between the oxide and the Ge{sub 1-x}Sn{sub x} layer. Finally, metal-oxide-semiconductor capacitors on the Ge capped sample showed well-behaved capacitance-voltage (C-V) characteristics with interface trap density (D{sub it}) in the range of 10{sup 12} eV{sup -1} cm{sup -2} in mid gap and higher close to the valence band edge.},
doi = {10.1063/1.3589992},
url = {https://www.osti.gov/biblio/21518431}, journal = {Applied Physics Letters},
issn = {0003-6951},
number = 19,
volume = 98,
place = {United States},
year = {2011},
month = {5}
}