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Yamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Suemitsu, Maki*; Narita, Yuzuru*; Teraoka, Yuden; Yoshigoe, Akitaka
Materials Research Society Symposium Proceedings, Vol.1074, p.36 - 40, 2008/00
In this study, we have investigated the bonding structure of ultrathin oxide films on Si(110) surface by real-time SR-PES experiments. Experiments were conducted at surface chemistry end-station settled at BL23SU in SPring-8. The oxidation temperature was 813 K and the O pressure was 1.110 Pa. As a result, we found that one of the surface core-level shifts in Si 2p spectrum, related to the 1st and the 2nd layer Si atoms, decreases rapidly, coincident with the rapid initial development of the O1s spectrum. This indicates high reactivity of the Si(110)-162 reconstructed surface with oxygen molecules.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*; Enta, Yoshiharu*
Japanese Journal of Applied Physics, Part 1, 46(4B), p.1888 - 1890, 2007/04
Times Cited Count:12 Percentile:44.00(Physics, Applied)Initial oxidation of Si(110) surface has been investigated by using real-time X-ray photoemission spectroscopy. The time evolution of the O 1s spectrum shows occurrence of rapid oxidation just after the introduction of the oxygen molecules, which is evidenced by the considerable peak intensity corresponding to oxygen exposure of as low as 1.5L (1L=1.3310 Pa s). This initial oxide is dominated by a state with a relatively low binding energy, which is gradually replaced by a state with a relatively high binding energy with the increase of the oxygen exposure, resulting in the low-KE shift of the O 1s peak. Comparison with previously reported O 1s spectra from dry-oxidized Si(111) surface suggests oxidation at or around the adatoms of Si(110)-162 clean surface as a likely oxidation state for this low-binding-energy peak.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
Shingaku Giho, 106(108), p.61 - 63, 2006/06
no abstracts in English
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Enta, Yoshiharu*; Narita, Yuzuru*
ECS Transactions, 3(2), p.311 - 316, 2006/00
Initial thermal oxidation of Si(110) surface has been investigated by using real-time X-ray photoemission spectroscopy with synchrotron radiation. The Si(110) initial oxidation is characterized by presence of a rapid oxidation just after the introduction of gaseous oxygen molecules. Peak separation of the O1s photoemission spectra suggests the presence of at least two distinct oxidation sites on the surface, which may reflect the complicated surface structure of the Si(110)-162 reconstruction.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Suemitsu, Maki*; Narita, Yuzuru*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
We have investigated oxidation at Si(110) surfaces via real-time photoemission spectroscopy with synchrotron radiation. We have already obtained the following information that rapid initial oxidation region was in the early stage of oxidation and one of shifted Si2p core level components was decreased with increasing oxide. Therefore, we focused our interest to the topmost ultrathin oxide-layer formation and investigated time evolution of oxide components of Si2p photoemission spectrum. All experiments were conducted at surface chemistry station of BL23SU in the SPring-8. The oxygen pressure was 1.010Pa and substrate temperature was 813 K. Consequently, concerning oxide components of Si2p during oxidation, the intensity of Si component was larger than that of Si until 1 ML oxidation.
Okabe, Toshihiro*; Ono, Hiroyuki*; Hatayama, Ichiro*; Waguri, Atsushi*; Sawada, Yuzuru*; Tsugawa, Hidehito*; Ichida, Tadao*; Nakane, Akio*; Sano, Teruo*; Tanaka, Kazuaki*; et al.
no journal, ,
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Hasegawa, Satoshi*; Goto, Seiichi*; Nakano, Takuya*; Suemitsu, Maki*; Narita, Yuzuru*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
We have investigated the initial oxidation process on an Si(110)-162 surface by real time synchrotron radiation photoemission spectroscopy (SR-XPS). As a result, a rapid initial oxidation regime was found to exist on this surface, which is not present on other crystal orientations. Analyses of the O1s spectra suggest insertion of oxygen atoms at the Si-Si bonds as the predominant process during initial oxidation. The rapid initial oxidation is accompanied by decrease of the Si2p subpeak that is related to Si(110)-162 reconstruction, indicating the preferential oxidation at the pentagon pair.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Konno, Atsushi*; Kato, Atsushi*; Narita, Yuzuru*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
no abstracts in English
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
no journal, ,
By using real-time photoemission spectroscopy, kinetics of initial oxidation of Si(110)-162 surface has been investigated and is compared with that of Si(100) surface. Dry oxidation of Si(110) shows rapid initial oxidation just after introduction of the oxygen, which is associated with an O1s state with a weaker binding energy. As the oxidation proceeds, another O1s state with a stronger binding energy develops. The rapid initial oxidation is related to oxidation at or around the Si(111)-like Si adatoms, which are reportedly present in the 162 reconstruction of the Si(110) surface.
Togashi, Hideaki*; Kato, Atsushi*; Yamamoto, Yoshihisa*; Konno, Atsushi*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
no journal, ,
Initial oxidation processes of Si(110) surface have not been studied although they are important for the next generation device. Now we observed time evolution of oxygen coverage at the Si(110)-162 surface in the initial oxidation region by using real-time photoemission spectroscopy with synchrotron radiation. As a conclusion, rapid initial oxidation processes, in which several tens per cent of the surface was oxidized just after oxygen exposure, were found in experimental conditions of 813 K and oxygen pressure of 1.110 Pa. Such a rapid initial oxidation process has not been observed in the initial oxidation of Si(100)-21 surface. This phenomenon may be related with adatom clusters, which exist periodically on the Si(110)-162 surface. For example, An adatom cluster, which consists of five Si atoms, shares 0.25 ML on the Si(110)-162 reconstruction surface in the pentagon-pair model. This model consistents with the initial oxygen coverage obtained in this experiment.
Kato, Atsushi*; Togashi, Hideaki*; Yamamoto, Yoshihisa*; Konno, Atsushi*; Narita, Yuzuru*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
Initial oxidation processes of ultra-thin oxide layers on Si(110)-162 surfaces have not been studied yet. Making clear the chemical reaction mechanisms is, however, important for device fabrication. We observed time evolution of oxide coverage on the Si(110)-162 surface at room temperature. The O1s photoemission spectrum increased with increasing oxygen dose and the peak position shifted to higher binding energy side at oxygen pressure of 1.110 Pa. This peak shift is responsible to two kinds of peak components and their independent time evolutions. Time evolution of each component, behaviour of Si2p spectrum, and thermal stability of the surface reveal that the oxidation of Si(110) surface has different characters in compared with that of Si(100) surface. These facts can be understood on the basis of adatom clusters on the Si(110) surface.
Togashi, Hideaki*; Kato, Atsushi*; Yamamoto, Yoshihisa*; Konno, Atsushi*; Narita, Yuzuru*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka; Takahashi, Yuya*; Asaoka, Hidehito
no journal, ,
no abstracts in English
Togashi, Hideaki*; Yamamoto, Yoshihisa*; Goto, Seiichi*; Takahashi, Yuya*; Nakano, Takuya*; Kato, Atsushi*; Hasegawa, Satoshi*; Konno, Atsushi*; Suemitsu, Maki*; Asaoka, Hidehito; et al.
no journal, ,
no abstracts in English
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Hasegawa, Satoshi*; Goto, Seiichi*; Nakano, Takuya*; Suemitsu, Maki*; Narita, Yuzuru*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Initial oxidation process of Si(110)-162 clean surface has been investigated with synchrotron radiation photoemission spectroscopy. We found that the intensity of the alpha peak, one of the surface core level shifts in the Si 2p photoemission spectra, decreased in the just early stage of oxidation. And it was possible to relate this component with the rapid initial oxidation, which was unique to Si(110) surface. According to recent studies, this component was attributed to the 1st and the 2nd Si layer. We also found that there were significant amount of Si component just after introducing the oxygen gas, which was contrast to the oxidation of Si(001) surface.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
no journal, ,
Initial kinetics in dry oxidation of Si(110) surface, a key technology in the next-generation CMOS technology, has been investigated by using synchrotron-radiation photoemission spectroscopy. As a result, the uptake curve of the Si(110) oxide in its high-pressure-low-temperature reaction regime is found to consist of three characteristic time domains, in sharp contrast with the single domain obtained on Si(001). The difference is understood in terms of the different atomistic arrangement on the surface.
Yamamoto, Yoshihisa*; Togashi, Hideaki*; Kato, Atsushi*; Suemitsu, Maki*; Narita, Yuzuru*; Teraoka, Yuden; Yoshigoe, Akitaka
no journal, ,
Formation processes of one atomic oxide layer and time evolution of chemical bonding states at the interface were investigated by using real-time photoemission spectroscopy with synchrotron radiation. Time evolutions for oxide components (Si:n=1-4) of Si2p photoemission spectra, observed in the conditions of 813K substrate temperature and 1.110 Pa O pressure, were analyzed. Rapid increase of Si component until oxygen dose of 10 L indicates existance of a reaction path through the Si state. On the other hand, contrary to the Si(001) oxidation, the Si component was larger than the Si component during oxidation. Reaction mechanisms was considered from these facts. Oxygen insertion into chain-like Si-Si bonds densely existing on the (110) surface (A bond) and Si-Si bonds on the (-110) surface is an origin of the first layer oxidation at Si(110) surface. The A bonds may be oxidized partially due to storage of oxidation strains.
Suemitsu, Maki*; Kato, Atsushi*; Togashi, Hideaki*; Konno, Atsushi*; Yamamoto, Yoshihisa*; Teraoka, Yuden; Yoshigoe, Akitaka; Narita, Yuzuru*
no journal, ,
no abstracts in English
Kato, Atsushi*; Togashi, Hideaki*; Yamamoto, Yoshihisa*; Konno, Atsushi*; Narita, Yuzuru*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka; Takahashi, Yuya*; Asaoka, Hidehito
no journal, ,
no abstracts in English
Kato, Atsushi*; Togashi, Hideaki*; Yamamoto, Yoshihisa*; Konno, Atsushi*; Narita, Yuzuru*; Suemitsu, Maki*; Teraoka, Yuden; Yoshigoe, Akitaka; Takahashi, Yuya*; Asaoka, Hidehito
no journal, ,
no abstracts in English