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 language | English |
|---|---|
| Pages (from-to) | 2896-2907 |
| Number of pages | 12 |
| Journal | Surface Science |
| Volume | 601 |
| Issue number | 14 |
| DOIs | |
| Publication status | Published - Jul 15 2007 |
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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 journal › Article
}
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 -