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Shigeaki Zaima

Bio: Shigeaki Zaima is an academic researcher from Nagoya University. The author has contributed to research in topics: Annealing (metallurgy) & Epitaxy. The author has an hindex of 31, co-authored 425 publications receiving 4666 citations.


Papers
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TL;DR: In this paper, high-resolution x-ray photoelectron spectroscopy (XPS) at 6 keV photon energy has been realized utilizing high-flux-density x rays from the third generation high-energy synchrotron radiation facility, SPring-8.
Abstract: High-resolution x-ray photoelectron spectroscopy (XPS) at 6 keV photon energy has been realized utilizing high-flux-density x rays from the third generation high-energy synchrotron radiation facility, SPring-8. The method has been applied to analysis of high-k HfO2/interlayer/Si complementary metal–oxide–semiconductor gate-dielectric structures. With the high energy resolution and high throughput of our system, chemical-state differences were observed in the Si 1s, Hf 3d, and O 1s peaks for as-deposited and annealed samples. The results revealed that a SiOxNy interlayer is more effective in controlling the interface structure than SiO2. Our results show the wide applicability of high resolution XPS with hard x rays from a synchrotron source.

310 citations

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TL;DR: In this paper, a new technique for analyzing the quantitative surface atomic geometry and the two-dimensional surface electron distribution is reported, and the remarkable effectiveness of this new technique is demonstrated for TiC(111).
Abstract: A new technique for analyzing the quantitative surface atomic geometry and the two-dimensional surface electron distribution is reported. The remarkable effectiveness of this new technique is demonstrated for TiC(111).

191 citations

Journal ArticleDOI
TL;DR: In this paper, a review of the technology of Ge1−xSnx-related group-IV semiconductor materials for developing Si-based nanoelectronics is presented.

136 citations

Journal ArticleDOI
TL;DR: In this article, a critical misfit strain control the onset of Sn precipitation at a given thickness of the Ge1−xSnx layer on virtual Ge substrates (v-Ge).
Abstract: We have investigated Sn precipitation and strain relaxation behaviors in the growth of Ge1−xSnx layers on virtual Ge substrates (v-Ge) for strain engineering of Ge. By varying misfit strain at Ge1−xSnx∕v-Ge and Ge1−ySny∕Ge1−xSnx interfaces, we found that a critical misfit strain controls the onset of Sn precipitation at a given thickness of the Ge1−xSnx layer. A compositionally step-graded method, in which the critical misfit strain is taken into account, was applied to the growth of strain-relaxed Ge1−xSnx layers on v-Ge. Postdeposition annealing at each growth step led to lateral propagation of threading dislocations preexisting in the layer and originating from v-Ge, which resulted in high degree of strain relaxation. An epitaxial Ge layer was grown on the strain-relaxed Ge1−xSnx layer and an in-plane tensile strain of 0.68% was achieved.

114 citations

Journal ArticleDOI
TL;DR: In this article, the compatibility of GeSn materials with source/drain engineering processes (B implantation and activation and NiGeSn formation) has been studied, and a low thermal budget has been determined for those processes on GeSn alloys.

107 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the authors summarized the major developments in Ge-on-Si photodetectors, including epitaxial growth and strain engineering, free-space and waveguide-integrated devices, as well as recent progress in Geon-On-Si avalanche photodets.
Abstract: The past decade has seen rapid progress in research into high-performance Ge-on-Si photodetectors. Owing to their excellent optoelectronic properties, which include high responsivity from visible to near-infrared wavelengths, high bandwidths and compatibility with silicon complementary metal–oxide–semiconductor circuits, these devices can be monolithically integrated with silicon-based read-out circuits for applications such as high-performance photonic data links and infrared imaging at low cost and low power consumption. This Review summarizes the major developments in Ge-on-Si photodetectors, including epitaxial growth and strain engineering, free-space and waveguide-integrated devices, as well as recent progress in Ge-on-Si avalanche photodetectors. Owing to their excellent optoelectronic properties, Ge-on-Si photodetector can be monolithically integrated with silicon-based read-out circuits for applications such as high-performance photonic data links and low-cost infrared imaging at low power consumption. This Review covers the major developments in Ge-on-Si photodetectors, including epitaxial growth and strain engineering, free-space and waveguide-integrated devices, as well as recent progress in Ge-on-Si avalanche photodetectors.

1,259 citations

Journal ArticleDOI
TL;DR: In this article, the status of SiC in terms of bulk crystal growth, unit device fabrication processes, device performance, circuits and sensors is discussed, focusing on demonstrated high-temperature applications, such as power transistors and rectifiers, turbine engine combustion monitoring, temperature sensors, analog and digital circuitry, flame detectors, and accelerometers.
Abstract: Silicon carbide (SiC), a material long known with potential for high-temperature, high-power, high-frequency, and radiation hardened applications, has emerged as the most mature of the wide-bandgap (2.0 eV ≲ Eg ≲ 7.0 eV) semiconductors since the release of commercial 6HSiC bulk substrates in 1991 and 4HSiC substrates in 1994. Following a brief introduction to SiC material properties, the status of SiC in terms of bulk crystal growth, unit device fabrication processes, device performance, circuits and sensors is discussed. Emphasis is placed upon demonstrated high-temperature applications, such as power transistors and rectifiers, turbine engine combustion monitoring, temperature sensors, analog and digital circuitry, flame detectors, and accelerometers. While individual device performances have been impressive (e.g. 4HSiC MESFETs with fmax of 42 GHz and over 2.8 W mm−1 power density; 4HSiC static induction transistors with 225 W power output at 600 MHz, 47% power added efficiency (PAE), and 200 V forward blocking voltage), material defects in SiC, in particular micropipe defects, remain the primary impediment to wide-spread application in commercial markets. Micropipe defect densities have been reduced from near the 1000 cm−2 order of magnitude in 1992 to 3.5 cm−2 at the research level in 1995.

1,249 citations

01 Mar 2001
TL;DR: In this paper, a unique chirality assignment was made for both metallic and semiconducting nanotubes of diameter d(t), using the parameters gamma(0) = 2.9 eV and omega(RBM) = 248/d(t).
Abstract: We show that the Raman scattering technique can give complete structural information for one-dimensional systems, such as carbon nanotubes. Resonant confocal micro-Raman spectroscopy of an (n,m) individual single-wall nanotube makes it possible to assign its chirality uniquely by measuring one radial breathing mode frequency omega(RBM) and using the theory of resonant transitions. A unique chirality assignment can be made for both metallic and semiconducting nanotubes of diameter d(t), using the parameters gamma(0) = 2.9 eV and omega(RBM) = 248/d(t). For example, the strong RBM intensity observed at 156 cm(-1) for 785 nm laser excitation is assigned to the (13,10) metallic chiral nanotube on a Si/SiO2 surface.

1,180 citations

Journal ArticleDOI
01 Dec 1993
TL;DR: In this article, a review of Si-based photonic components and optoelectronic integration techniques, both hybrid and monolithic, is presented, with a focus on column IV materials (Si, Ge, C and Sn).
Abstract: The decade of the 1990's is an opportune time for scientists and engineers to create cost-effective silicon "superchips" that merge silicon photonics with advanced silicon electronics on a silicon substrate. We can expect significant electrooptical devices from Column IV materials (Si, Ge, C and Sn) for a host of applications. The best devices will use strained-layer epitaxy, doped heterostructures, and bandgap engineering of quantum-confined structures. This paper reviews Si-based photonic components and optoelectronic integration techniques, both hybrid and monolithic. >

693 citations

Journal ArticleDOI
TL;DR: In this article, the authors present the present knowledge on tantalum pentoxide (Ta 2 O 5 ) thin films and their applications in the field of microelectronics and integrated microtechnologies.
Abstract: This paper reviews the present knowledge on tantalum pentoxide (Ta 2 O 5 ) thin films and their applications in the field of microelectronics and integrated microtechnologies. Different methods used to produce tantalum oxide layers are described, emphazing elaboration mechanisms and key parameters for each technique. We also review recent advances in the deposition of Ta 2 O 5 in the particular field of microelectronics where high quality layers are required from the structural and electrical points of view. The physical, structural, optical, chemical and electrical properties of tantalum oxide thin films on semiconductors are then presented and essential film parameters, such as optical index, film density or dielectric permittivity, are discussed. After a reminder of the basic mechanisms that control the bulk electrical conduction in insulating films, we carefully examine the origin of leakage currents in Ta 2 O 5 and present the state-of-the-art concerning the insulating behaviour of tantalum oxide layers. Finally, applications of tantalum oxide thin films are presented in the last part of this paper. We show how Ta 2 O 5 has been employed as an antireflection coating, insulating layer, gate oxide, corrosion resistant material, and sensitive layer in a wide variety of components, circuits and sensors.

627 citations