High-resolution photoemission studies of the interfacial reactivity and interfacial energetics of Au and Cu Schottky barriers on methyl-terminated Si(1 1 1) surfaces

Ralf Hunger, Rainer Fritsche, Bengt Jaeckel, Lauren J. Webb, Wolfram Jaegermann, Nathan S Lewis

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The Schottky junction formation by the stepwise evaporation of gold and copper, respectively, onto methyl-terminated silicon, CH3-Si(1 1 1), was investigated by synchrotron X-ray photoelectron spectroscopy. During the junction formation process, interface reactions occurred as revealed by the appearance of chemically shifted Si 2p components. Upon deposition of Au, the formation of about one monolayer of gold silicide, SiAu3, with a Si 2p chemical shift of +0.75(2) eV, was observed. The SiAu3 floated on top of the growing gold layer. Similarly, for the deposition of Cu, the methyl termination layer was partially disrupted, as indicated by the appearance of a -0.28(2) eV chemically shifted Si 2p component attributable to an interfacial copper silicide phase, SiCu3. Hence, the termination of the Si(1 1 1) surface by methyl groups did not completely prevent interfacial reactions, but did reduce the amount interfacial reaction products as compared to bare Si(1 1 1)-(7 × 7) surfaces. Electron Schottky barrier heights of 0.78(8) eV (Au) and 0.61(8) eV (Cu) were measured. Within the experimental uncertainty the observed Schottky barriers were identical to those ones obtained on non-passivated, (7 × 7)-reconstructed Si(1 1 1) surfaces. Thus, the modification of the electronic properties of the silicon-metal contact requires the complete absence of interfacial reactions.

Original languageEnglish
Pages (from-to)2896-2907
Number of pages12
JournalSurface Science
Volume601
Issue number14
DOIs
Publication statusPublished - Jul 15 2007

Fingerprint

Photoemission
Surface chemistry
Gold
photoelectric emission
reactivity
Silicon
gold
Copper
high resolution
copper
Chemical shift
silicon
Synchrotrons
Reaction products
Electronic properties
reaction products
chemical equilibrium
electric contacts
Monolayers
synchrotrons

Keywords

  • Alkanes
  • Copper
  • Gold
  • Metal-semiconductor interfaces
  • Schottky barrier
  • Silicides
  • Silicon
  • Synchrotron radiation photoelectron spectroscopy

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Condensed Matter Physics
  • Surfaces and Interfaces

Cite this

High-resolution photoemission studies of the interfacial reactivity and interfacial energetics of Au and Cu Schottky barriers on methyl-terminated Si(1 1 1) surfaces. / Hunger, Ralf; Fritsche, Rainer; Jaeckel, Bengt; Webb, Lauren J.; Jaegermann, Wolfram; Lewis, Nathan S.

In: Surface Science, Vol. 601, No. 14, 15.07.2007, p. 2896-2907.

Research output: Contribution to journalArticle

Hunger, Ralf ; Fritsche, Rainer ; Jaeckel, Bengt ; Webb, Lauren J. ; Jaegermann, Wolfram ; Lewis, Nathan S. / High-resolution photoemission studies of the interfacial reactivity and interfacial energetics of Au and Cu Schottky barriers on methyl-terminated Si(1 1 1) surfaces. In: Surface Science. 2007 ; Vol. 601, No. 14. pp. 2896-2907.
@article{3f0e136d68cb4a4690c75634cf13d837,
title = "High-resolution photoemission studies of the interfacial reactivity and interfacial energetics of Au and Cu Schottky barriers on methyl-terminated Si(1 1 1) surfaces",
abstract = "The Schottky junction formation by the stepwise evaporation of gold and copper, respectively, onto methyl-terminated silicon, CH3-Si(1 1 1), was investigated by synchrotron X-ray photoelectron spectroscopy. During the junction formation process, interface reactions occurred as revealed by the appearance of chemically shifted Si 2p components. Upon deposition of Au, the formation of about one monolayer of gold silicide, SiAu3, with a Si 2p chemical shift of +0.75(2) eV, was observed. The SiAu3 floated on top of the growing gold layer. Similarly, for the deposition of Cu, the methyl termination layer was partially disrupted, as indicated by the appearance of a -0.28(2) eV chemically shifted Si 2p component attributable to an interfacial copper silicide phase, SiCu3. Hence, the termination of the Si(1 1 1) surface by methyl groups did not completely prevent interfacial reactions, but did reduce the amount interfacial reaction products as compared to bare Si(1 1 1)-(7 × 7) surfaces. Electron Schottky barrier heights of 0.78(8) eV (Au) and 0.61(8) eV (Cu) were measured. Within the experimental uncertainty the observed Schottky barriers were identical to those ones obtained on non-passivated, (7 × 7)-reconstructed Si(1 1 1) surfaces. Thus, the modification of the electronic properties of the silicon-metal contact requires the complete absence of interfacial reactions.",
keywords = "Alkanes, Copper, Gold, Metal-semiconductor interfaces, Schottky barrier, Silicides, Silicon, Synchrotron radiation photoelectron spectroscopy",
author = "Ralf Hunger and Rainer Fritsche and Bengt Jaeckel and Webb, {Lauren J.} and Wolfram Jaegermann and Lewis, {Nathan S}",
year = "2007",
month = "7",
day = "15",
doi = "10.1016/j.susc.2007.04.249",
language = "English",
volume = "601",
pages = "2896--2907",
journal = "Surface Science",
issn = "0039-6028",
publisher = "Elsevier",
number = "14",

}

TY - JOUR

T1 - High-resolution photoemission studies of the interfacial reactivity and interfacial energetics of Au and Cu Schottky barriers on methyl-terminated Si(1 1 1) surfaces

AU - Hunger, Ralf

AU - Fritsche, Rainer

AU - Jaeckel, Bengt

AU - Webb, Lauren J.

AU - Jaegermann, Wolfram

AU - Lewis, Nathan S

PY - 2007/7/15

Y1 - 2007/7/15

N2 - The Schottky junction formation by the stepwise evaporation of gold and copper, respectively, onto methyl-terminated silicon, CH3-Si(1 1 1), was investigated by synchrotron X-ray photoelectron spectroscopy. During the junction formation process, interface reactions occurred as revealed by the appearance of chemically shifted Si 2p components. Upon deposition of Au, the formation of about one monolayer of gold silicide, SiAu3, with a Si 2p chemical shift of +0.75(2) eV, was observed. The SiAu3 floated on top of the growing gold layer. Similarly, for the deposition of Cu, the methyl termination layer was partially disrupted, as indicated by the appearance of a -0.28(2) eV chemically shifted Si 2p component attributable to an interfacial copper silicide phase, SiCu3. Hence, the termination of the Si(1 1 1) surface by methyl groups did not completely prevent interfacial reactions, but did reduce the amount interfacial reaction products as compared to bare Si(1 1 1)-(7 × 7) surfaces. Electron Schottky barrier heights of 0.78(8) eV (Au) and 0.61(8) eV (Cu) were measured. Within the experimental uncertainty the observed Schottky barriers were identical to those ones obtained on non-passivated, (7 × 7)-reconstructed Si(1 1 1) surfaces. Thus, the modification of the electronic properties of the silicon-metal contact requires the complete absence of interfacial reactions.

AB - The Schottky junction formation by the stepwise evaporation of gold and copper, respectively, onto methyl-terminated silicon, CH3-Si(1 1 1), was investigated by synchrotron X-ray photoelectron spectroscopy. During the junction formation process, interface reactions occurred as revealed by the appearance of chemically shifted Si 2p components. Upon deposition of Au, the formation of about one monolayer of gold silicide, SiAu3, with a Si 2p chemical shift of +0.75(2) eV, was observed. The SiAu3 floated on top of the growing gold layer. Similarly, for the deposition of Cu, the methyl termination layer was partially disrupted, as indicated by the appearance of a -0.28(2) eV chemically shifted Si 2p component attributable to an interfacial copper silicide phase, SiCu3. Hence, the termination of the Si(1 1 1) surface by methyl groups did not completely prevent interfacial reactions, but did reduce the amount interfacial reaction products as compared to bare Si(1 1 1)-(7 × 7) surfaces. Electron Schottky barrier heights of 0.78(8) eV (Au) and 0.61(8) eV (Cu) were measured. Within the experimental uncertainty the observed Schottky barriers were identical to those ones obtained on non-passivated, (7 × 7)-reconstructed Si(1 1 1) surfaces. Thus, the modification of the electronic properties of the silicon-metal contact requires the complete absence of interfacial reactions.

KW - Alkanes

KW - Copper

KW - Gold

KW - Metal-semiconductor interfaces

KW - Schottky barrier

KW - Silicides

KW - Silicon

KW - Synchrotron radiation photoelectron spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=34447312494&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34447312494&partnerID=8YFLogxK

U2 - 10.1016/j.susc.2007.04.249

DO - 10.1016/j.susc.2007.04.249

M3 - Article

AN - SCOPUS:34447312494

VL - 601

SP - 2896

EP - 2907

JO - Surface Science

JF - Surface Science

SN - 0039-6028

IS - 14

ER -