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Niigata-shi, Japan

Zaima S.,Nagoya University | Nakatsuka O.,Nagoya University | Shimura Y.,Nagoya University | Shimura Y.,Japan Society for the Promotion of Science | And 2 more authors.
ICSICT-2010 - 2010 10th IEEE International Conference on Solid-State and Integrated Circuit Technology, Proceedings | Year: 2010

We have investigated the growth and crystalline properties of tensile-strained Ge and Ge1-xSnx heteroepitaxial layers for high-mobility channels. The low temperature growth and the large misfit strain between Ge1-xSnx and Si leads to the high density of defects such as vacancy in Ge1-xSnx layers. They effectively enhance the propagation of misfit dislocations and the strain relaxation with suppressing the precipitation of Sn atoms from Ge 1-xSnx layers. As a result, we succeeded in growing strain-relaxed Ge1-xSnx layers with a Sn content over 9% by controlling the dislocation structures. We also characterized the Hall mobility of Ge1-xSnx layers and found that the Sn incorporation into Ge effectively reduced the concentration of holes related to vacancy defects, and improved on the hole mobility. ©2010 IEEE. Source


Kanbe H.,Kochi University of Technology | Hirose M.,Kochi University of Technology | Hirose M.,Covalent Materials Co. | Ito T.,Kochi University of Technology | Taniwaki M.,Kochi University of Technology
Journal of Electronic Materials | Year: 2010

Ge/Si heterojunctions formed by wet wafer bonding were observed using transmission electron microscopy and energy-dispersive x-ray spectroscopy. For the samples annealed at 880°C, there was a transition layer at the heterointerface with modified regions in the Si and Ge extending 20 nm to 30 nm from the interface. In these modified regions, crystal defects were observed, and a large amount of Ge was detected on the Si side of the junction. For the samples annealed at 250°C or 350°C, the transition layers had an amorphous-like structure with a thickness of about 10 nm. No modified layer or enlargement of lattice spacing was observed. © 2010 TMS. Source


Kato T.,Osaka University | Nakamura Y.,Osaka University | Kikkawa J.,Osaka University | Sakai A.,Osaka University | And 7 more authors.
Thin Solid Films | Year: 2010

The use of Si(011)/Si(001) direct silicon bonding (DSB) substrates is a key for future complementary metal-oxide-semiconductor device technology. In conventional bonding process, it is necessary to remove interfacial SiO2 to achieve direct atomic bonding. In this study, using X-ray microdiffraction and transmission electron microscopy, we investigate the structural changes caused by oxide out-diffusion annealing (ODA). It is revealed that crystallinity of the bonded Si(011) layer is degraded after low temperature ODA and gradually recovered with an increase in the ODA temperature and time, which is well correlated with the interfacial SiO2/Si morphology. Characteristic domain textures depending on the ODA temperature are also detected. © 2009 Elsevier B.V. All rights reserved. Source


Yamashita M.,Osaka University | Nakamura Y.,Osaka University | Nakamura Y.,Japan Science and Technology Agency | Yamamoto A.,Osaka University | And 3 more authors.
Applied Surface Science | Year: 2013

We have investigated vicinal Si(1 1 0) surfaces with various off-angles using atomic force microscopy and transmission electron microscopy. The vicinal surfaces were tilted from the exact Si(1 1 0) surfaces by 2-8° toward the [1 1̄0] direction. Peculiar surface structures were observed with a strong dependence on the off-angles, including triangular pyramid-like structures on 2° off surfaces, line structures on 4° and 8° off surfaces and nanometer-height mountain structures on 6° off surfaces. The structures on 2° and 4° off surfaces were based on the stair-like structure composed of Si(1 1 0) terraces and monolayer steps. On the other hand, 6° and 8° off surfaces could be understood in terms of Si(1 1 0) terraces and bunched steps. © 2012 Elsevier B.V. All rights reserved. Source


Kariyazaki H.,Okayama Prefectural University | Aoki T.,Okayama Prefectural University | Aoki T.,Covalent Materials Co. | Izunome K.,Covalent Materials Co. | Sueoka K.,Okayama Prefectural University
Journal of Applied Physics | Year: 2010

Direct silicon bonded (DSB) substrates with (110)/(100) hybrid orientation technology are attracting considerable attention as a promising technology for high performance bulk complementary metal-oxide semiconductor technology. We have investigated the structure and the gettering efficiency of the (110)/(100) interface parallelling each 〈 110 〉 direction (DSB interface) by molecular dynamics (MD) and first-principles calculation. In MD calculations, initial calculation cells of 15 atomic-configurations with coincidence-site lattices were prepared. It was found that (i) the calculated DSB interface was stable independent of the initial atomic-configurations and (ii) the interfacial structures were essentially the same among the calculated models. Moreover, the calculated interfacial structure corresponds to the reported TEM observation. The first-principles calculation showed that Si atoms in the DSB interface formed covalent bonding. The dangling bonds in Si (110) and (100) surfaces disappeared due to restructuring in the DSB interface. Furthermore, the DSB interface, which exists just below the device active region, was found to be an efficient gettering site for Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Hf atoms. © 2010 American Institute of Physics. Source

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