Evolution of interface properties of electrodeposited Ni/GaAs(001) contacts upon annealing

This paper reviews recent efforts by authors' group to utilize electrochemical processes for formation, processing and gate control of III-V semiconductor nanostructures. Topics include precise photo anodic and pulsed anodic etching of InP, formation of arrays of <001>-oriented straight nanopores in n-type (001) InP by anodization and their possible applications, and macroscopic and nanometer-scale metal contact formation on GaAs, InP and GaN by a pulsed in-situ electrochemical process, which remarkably reduces Fermi level pinning. All the results indicate that electrochemical processes can achieve unique and important results which the conventional semiconductor technology cannot realize, anticipating their increased importance in future semiconductor nanotechnology and nanoelectronics. Key words:III-V semiconductors, anodic etching, nanopore, electrodeposition, Schottky barrier 1.IntroductionIt is widely recognized that artificial semiconductor nanostructures such as quantum wires (QWRs) and quantum dots(QDs) give rise to new rich functionalities to materials. They produce new quantum state spectra with novel state transitions and linear and non-linear quantum transport phenomena, and open up opportunities for novel quantum devices which control quantum-mechanical behavior of electrons and photons in various sophisticated ways.The standard approach for semiconductor nanostructure formation is to use fine crystal growth techniques such as molecular beam epitaxy (MBE) and metalorganic vapor phase epitaxy (MOVPE). To fabricate devices, various standard etching and metal deposition techniques are used together with standard lithography techniques. However, the electrochemical approaches, if it attains sufficiently high controllability at the nanometerscale, seems to be highly useful for nanostructure formation and processing. The expected advantages include: (1) process simplicity and versatility, (2) capability of self-organization, (3) low processing temperature, (4) low process induced damage, (5) precise electrical control and (6) low processing costs.Some well known examples are porous Si formation [1,2] and use of anodized alumina as nanostructure templates for formation of carbon nanotubes [3].The purpose of this paper is to review recent attempts by the authors' group at RCIQE, Hokkaido University, that have been carried out in order to investigate feasibility of utilizing electrochemical processes for nanometer-scale processing and nanostructure formation in III-V semiconductors. Topics discussed in this paper include controlled (1) anodic etching of InP,

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“…Electrochemical deposition of Bi on GaAs was reported by Vereecken et al [48]. Epitaxial growth of Ni on GaAs has also recently reported [49].…”

Section: Formation Of Macroscopic Ms Interfaces By Pulsed In-situ Elementioning

confidence: 92%

Electrochemical processes for formation, processing and gate control of III–V semiconductor nanostructures

Hasegawa

Sato

2005

Electrochimica Acta

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“…To date several reports of iron group metal deposition on GaAs have been published with the most recent studies focusing on the question of epitaxy or texture. All three iron-group elements Ni, 19,20 Co, 21 and Fe 22,23 have been examined. Of particular interest are two recent studies of the structural and magnetic properties of electrodeposited Fe on GaAs͑001͒.…”

mentioning

confidence: 99%

A Structural Study of Electrodeposited Fe on n-GaAs(001)

Svedberg

Mallett

Bendersky

et al. 2006

J. Electrochem. Soc.

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The microstructure of Fe films electrodeposited onto n-GaAs͑001͒ from FeCl 2 and FeSO 4 -͑NH 4 ͒ 2 SO 4 electrolytes was examined by X-ray and electron diffraction. Symmetrical -2 X-Ray diffraction from films deposited from chloride solutions indicates a dominant ͑001͒ texture with the presence of additional minority orientations. In contrast, deposition from an ammonium sulfate electrolyte yields films that only exhibit ͑001͒ scattering in the -2 geometry. Transmission electron microscopy ͑TEM͒ crosssectional images of films grown in chloride solutions reveal intermittent cube-on-cube epitaxy that is also evident in plan view TEM dark field images. Interestingly, X-ray pole figure measurements for all specimens examined reveal an additional ͑221͒ orientation that is undetectable by symmetric -2 diffraction. The ͑221͒ oriented material most likely derives from twinning of ͑001͒ oriented grains during growth.

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“…Various questions are still unanswered, such as the predictions of the phase, which will precipitate among the different phases that exist for the Co/Si system, how thick the silicide layer formed at the interface will be, and how it will vary with film thickness. In addition to this, these properties are also very susceptible to degradation with temperature due to the significant intermixing of the underlying substrate element into the over layer [17,18]. Using micro-Raman spectroscopy, the goal of this study is to find out how thickness and temperature affect the Co/Si interface.…”

Section: Introductionmentioning

confidence: 99%

Probing Co/Si Interface by Raman Spectroscopy

Brajpuriya¹

2022

J. Nano- Electron. Phys.

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The characteristics of the metal on the Si surface have been extensively explored due to the industrial relevance of transition metal silicide in integrated circuit technology and scientific interest in the influence of the adlayer on Si substrate reconstruction and heterodiffusion. Even though the interaction of Co with Si is not entirely understood, there are still disagreements over the nature of the Co/Si system. Several problems remain unsolved, including predictions of the phase that would precipitate among the several phases of the Co/Si system as a function of film thickness and temperature. Therefore, in order to understand the same, cobalt (Co) thin films of thicknesses 10, 40, and 100 nm were produced by electron beam physical vapor on silicon substrates. After deposition, the samples were further annealed at 200, 300, and 400 °C for 2 h. Micro-Raman spectroscopy (due to its non-destructive nature) was used to analyze the chemical composition and silicide formation at the interface as a result of the thickness and temperature variation in asdeposited and annealed samples. The results demonstrate that the grown films are of high quality and devoid of impurities. Studies reveal that silicide is formed during deposition at the interface, and the development of a new band at 1550 cm -1 as a result of annealing shows structural transformation from CoSi to CoSi2, which strengthens further at higher annealing temperatures.

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Evolution of interface properties of electrodeposited Ni/GaAs(001) contacts upon annealing

Cited by 12 publications

References 13 publications

Electrochemical processes for formation, processing and gate control of III–V semiconductor nanostructures

Electrochemical processes for formation, processing and gate control of III–V semiconductor nanostructures

A Structural Study of Electrodeposited Fe on n-GaAs(001)

Probing Co/Si Interface by Raman Spectroscopy

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