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Author Lei, Dian ♦ Wang, Wei ♦ Gong, Xiao ♦ Liang, Gengchiau ♦ Yeo, Yee-Chia ♦ Zhang, Zheng ♦ Pan, Jisheng ♦ Tok, Eng-Soon
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ATOMS ♦ CARRIER DENSITY ♦ CHEMICAL BONDS ♦ DEPOSITION ♦ DIELECTRIC MATERIALS ♦ HAFNIUM OXIDES ♦ HOLE MOBILITY ♦ INTERFACES ♦ MOSFET ♦ PASSIVATION ♦ SULFUR ♦ SURFACES ♦ TEMPERATURE RANGE 0273-0400 K ♦ TRAPS ♦ VALENCE ♦ X-RAY PHOTOELECTRON SPECTROSCOPY
Abstract The effect of room temperature sulfur passivation of the surface of Ge{sub 0.83}Sn{sub 0.17} prior to high-k dielectric (HfO{sub 2}) deposition is investigated. X-ray photoelectron spectroscopy (XPS) was used to examine the chemical bonding at the interface of HfO{sub 2} and Ge{sub 0.83}Sn{sub 0.17}. Sulfur passivation is found to be effective in suppressing the formation of both Ge oxides and Sn oxides. A comparison of XPS results for sulfur-passivated and non-passivated Ge{sub 0.83}Sn{sub 0.17} samples shows that sulfur passivation of the GeSn surface could also suppress the surface segregation of Sn atoms. In addition, sulfur passivation reduces the interface trap density D{sub it} at the high-k dielectric/Ge{sub 0.83}Sn{sub 0.17} interface from the valence band edge to the midgap of Ge{sub 0.83}Sn{sub 0.17}, as compared with a non-passivated control. The impact of the improved D{sub it} is demonstrated in Ge{sub 0.83}Sn{sub 0.17} p-channel metal-oxide-semiconductor field-effect transistors (p-MOSFETs). Ge{sub 0.83}Sn{sub 0.17} p-MOSFETs with sulfur passivation show improved subthreshold swing S, intrinsic transconductance G{sub m,int}, and effective hole mobility μ{sub eff} as compared with the non-passivated control. At a high inversion carrier density N{sub inv} of 1 × 10{sup 13 }cm{sup −2}, sulfur passivation increases μ{sub eff} by 25% in Ge{sub 0.83}Sn{sub 0.17} p-MOSFETs.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-01-14
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 119
Issue Number 2


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