Electron beam oxidation of semiconductors (one mechanism of electron beam processes)

Wada, Takahiro

doi:10.1063/1.99209

Cited by 21 publications

(6 citation statements)

References 11 publications

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“…They could contribute to the formation of CdO. However, previous work also points out that the oxygen species in the column of the TEM can participate in reactions under beam stimulation . In order to examine whether the phase transition involves oxygen species from the gas phase or the surface of the ribbons, an in situ heating experiment was performed inside the TEM using a Micro‐Electro‐Mechanical System (MEMS, Figure a) based heating holder (Figure S10, Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

Atomic‐Scale Observation of Irradiation‐Induced Surface Oxidation by In Situ Transmission Electron Microscopy

Xing

Jones

Fan

et al. 2016

Adv Materials Inter

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Irradiation of materials with high energy particles can induce structural transitions or trigger chemical reactions. Understanding the underlying mechanism for irradiation-induced phenomena is of both scientific and technical importance. Here, CdS nanoribbons are used as a model system to study structural and chemical evolution under electron-beam irradiation by in situ transmission electron microscopy. Real-time imaging clearly shows that upon irradiation, CdS is transformed to CdO with the formation of orientation-dependent relationships at surface. The structural transition can always be triggered with a dose rate beyond 601 e/Å²s in this system. A lower dose rate instead leads to the deposition of an amorphous carbon layer on the surface. Based on real-time observations and density functional theory calculations, a mechanism for the oxidation of CdS to CdO is proposed. It is essentially a thermodynamically driven process that is mediated by the formation of sulfur vacancies due to the electron-beam irradiation. It is also demonstrated that the surface oxidation can be suppressed by pre-depositing a conductive carbon layer on the CdS surface. The carbon coating can effectively reduce the rate of sulfur vacancy creation, thus decreasing defect-mediated oxidation. In addition, it isolates the active oxygen radicals from the ribbon, blocking the pathway for oxygen diffusion

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Section: Resultsmentioning

confidence: 99%

Atomic‐Scale Observation of Irradiation‐Induced Surface Oxidation by In Situ Transmission Electron Microscopy

Xing

Jones

Fan

et al. 2016

Adv Materials Inter

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“…As part of ongoing research into enhanced diffusion, Wada et al [7 -9] in a study on ntype germanium reported that the Hall coefficient in a 110 µm thick layer of the material changes from negative to positive at a depth of about 50 µm after exposure to an electron beam with total flux of 10 16 electrons/cm 2 at 7 MeV. Electron beam doping (EBD), first proposed by Wada [7][8][9][10], has been further developed by the present authors [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In the present paper, the effects of fine superdiffusion process was studied for three-layer structure.…”

Section: Introductionmentioning

confidence: 92%

Superdiffusion of impurity atoms in damage‐free regions of semiconductors

Wada¹,

Fujimoto

2003

phys. stat. sol. (c)

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The effect of the elegant superdiffusion process was examined in the unirradiated region for three layer structures. GaAs semiconductor substrates coated with vacuum-evaporated Si were doped with Si by electron beam doping (EBD) at 750 keV using GaAs/Si//Si/GaAs systems. The samples were exposed to an electron beam with a fluence of (3.7-5.0) × 10 17 electrons/cm 2 with a mean current density of 8.1 A/cm 2 in a Van de Graaff accelerator at 100 °C in a N 2 gas atmosphere. The irradiated samples were inspected by secondary-ion mass spectrometry and photoluminescence analysis, revealing the occurrence of superdiffusion. It was found that EBD occurs as a result of the interstitial migration of displaced interstitial atoms toward the Si//Si interface, strong surface diffusion at the interface, and high impurity concentrations at the interface that induce concentration-and recombination-enhanced diffusion. Two kickout mechanisms were identified for substitution of migrating atoms in the GaAs substrate.

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“…The role of inelastic electronic scattering caused by electron-beam and photon-beam irradiation in atomic migration phenomena at low-temperature has recently become a hot topic [30][31][32][33][34][35] in solid-state physics. Takahashi et al 30 formed a GaAs quantum wire by using electron-beaminduced selective growth technology.…”

Section: Mechanism Of Enhanced Oxygen Diffusionmentioning

confidence: 99%

“…A narrow quasiquantum GaAs wire can be formed by using in situ electron-beam irradiation and simultaneously supplying trimethyl-gallium and cracked AsH 3 . Wada et al [31][32][33] achieved lowtemperature diffusion ͑doping͒, epitaxy, and oxidation by electron-beam irradiation of waters or metal layers on various substrate materials. Akazawa et al 33 reported that photostimulated evaporation of amorphous SiO 2 and microcrystalline Si can be induced by synchrotron radiation in an ultrahigh vacuum and in a H 2 ambient.…”

Section: Mechanism Of Enhanced Oxygen Diffusionmentioning

confidence: 99%

“…Wada et al [31][32][33] achieved lowtemperature diffusion ͑doping͒, epitaxy, and oxidation by electron-beam irradiation of waters or metal layers on various substrate materials. Akazawa et al 33 reported that photostimulated evaporation of amorphous SiO 2 and microcrystalline Si can be induced by synchrotron radiation in an ultrahigh vacuum and in a H 2 ambient. And Sato et al 35 reported that by irradiating a 300-nm-thick amorphous silicon layer on a crystalline substrate with synchrotronradiation x-rays at RT, they could induce homogeneous crystalline nucleation during the 600°C postannealing process.…”

Section: Mechanism Of Enhanced Oxygen Diffusionmentioning

confidence: 99%

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Epitaxial crystallization during 600 °C furnace annealing of amorphous Si layer deposited by low-pressure chemical-vapor-deposition and irradiated with 1-MeV Xe ions

Nakata

1997

Journal of Applied Physics

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Articles you may be interested inThree-step growth of metamorphic GaAs on Si(001) by low-pressure metal organic chemical vapor depositionThe amorphous Si layers deposited by low-pressure chemical vapor deposition on ͑100͒-crystal-Si substrates and subjected to Xe-ion-beam irradiation are crystallized epitaxially in a layer-by-layer fashion to the surface during 600°C furnace annealing. Layer-by-layer crystallization can be accomplished by irradiating the layers with a 1-MeV Xe-ion-beam for a 2ϫ10 15 /cm 2 dose at 310°C prior to furnace annealing. In all cases during furnace annealing that amorphous Si layers are polycrystallized or are grown vertically in isolated epitaxial-columnar-structures and then grown laterally into the amorphous region surrounding each column, the ion-beam-induced epitaxial crystallization ͑IBIEC͒ method epitaxially crystallizes them in a layer-by-layer fashion. This is because O atoms that were at the initial interface and that prevented layer-by-layer crystallization or columnar-epitaxial-growth diffuse remarkably because of irradiation. This diffusion decreases the peak concentration and facilitates layer-by-layer crystallization. O atoms at the interface are also diffused by irradiation with 80-keV P, 100-keV As, and 150-keV As ions. This diffusion results in the columnar growth during 600-800°C furnace annealing. Whether layer-by-layer growth or columnar growth occurs during the furnace annealing depends on the peak concentration of oxygen at the interface. Direct evidence is shown that O diffusion is enhanced by the amount of inelastic electronic scattering of incident ion beam under the same elastic nuclear scattering conditions. The rates of IBIEC and of epitaxial crystallization during furnace annealing after 1-MeV Xe-ion-beam irradiation for a 2ϫ10 15 /cm 2 dose are affected by the amount of oxygen in the amorphous layer. The rate of layer-by-layer IBIEC using a 1-MeV Xe-ion-beam is nearly twice as high for a sample heated in the deposition furnace after evacuation as it is for a sample heated before evacuation. This difference is due to the smaller amount of oxygen in the amorphous Si layer of the former sample.

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Electron beam oxidation of semiconductors (one mechanism of electron beam processes)

Cited by 21 publications

References 11 publications

Atomic‐Scale Observation of Irradiation‐Induced Surface Oxidation by In Situ Transmission Electron Microscopy

Atomic‐Scale Observation of Irradiation‐Induced Surface Oxidation by In Situ Transmission Electron Microscopy

Superdiffusion of impurity atoms in damage‐free regions of semiconductors

Epitaxial crystallization during 600 °C furnace annealing of amorphous Si layer deposited by low-pressure chemical-vapor-deposition and irradiated with 1-MeV Xe ions

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