Low Energy Ion Irradiation Effect on Electron Transport in Gaas/Algaas Heterostructures

1994 ◽  
Vol 354 ◽  
Author(s):  
J. Yanagisawa ◽  
A. Nozawa ◽  
Y. Yuba ◽  
S. Takaoka ◽  
K. Murase ◽  
...  
Keyword(s):  
Carrier Density ◽  
Focused Ion Beam ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Sample Surface ◽  
Low Energy ◽  
Hall Resistance ◽  
Irradiation Effect ◽  
Before And After ◽  
Ar Gas

AbstractEffects of low energy ion beam induced damages on transport properties of a two-dimensional electron gas (2DEG) system in GaAs/AlGaAs heterostructures have been investigated. 1 keV Ar ions were irradiated on the sample surface at several ion doses (1011 - 1013 cm-2). Carrier density and electron mobility of the 2DEG formed at about 90 nm below the GaAs/AlGaAs heterostructure surface were estimated at 1.5 K by Hall resistance and longitudinal resistance measurements before and after annealing at 400°C for 10 min in an Ar gas ambient. The temperature dependence of those values was also measured for as-grown and for 1013 cm-2 ion irradiated and subsequently annealed samples. Typical results show that carrier density and mobility are not degraded severely by Ar ion irradiation at doses of 1013 cm-2 and suggest the possibility to fabricate buried structures in GaAs/AlGaAs heterostructures using low energy Si focused ion beam (FIB) irradiation and subsequent in situ overlayer growth by MBE.

Low Energy Focused Ion Beam Processing

1992 ◽  
Vol 279 ◽  
Author(s):  
Kenji Gamo
Keyword(s):  
Focused Ion Beam ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Etching Rate ◽  
High Mobility ◽  
Low Energy ◽  
High Electron ◽  
Optimization Of Process Parameters ◽  
High Etching Rate

ABSTRACTFocused ion beam (FIB) techniques have many advantages which stem from being maskless and have attracted much interest for various applications includingin situprocessing. However, reduction of damage and improvement of throughput are problems awaiting solution. For reduction of damage, low energy FIB is promising and for improvement of throughput, understanding of the basic processes and optimization of process parameters based on this understanding is crucial. This paper discusses characteristics of low energy FIB system, ion beam assisted etching and ion implantation, and effect of damage with putting emphasize onin situfabrication. Low energy (0.05–25keV) FIB system being developed forms -lOOnm diameter ion beams and is connected with molecular beam epitaxy system. Many results indicate that low damage, maskless ion beam assisted etching is feasible using low energy beams. Recently it was also shown that for ion beam assisted etching of GaAs, pulse irradiation yields very high etching rate of 500/ion. This indicates that the optimization of the relative ratio of ion irradiation and reactant gas supply as important to achieve high etching rate. Low energy FIB is also important for selective doping for high electron mobility heterostructures of GaAs/GaAlAs, because high mobility is significantly degraded by a slight damage.

Shape deformation of colloidal titania nanoparticles by means of ion irradiation

2008 ◽  
Vol 1087 ◽  
Author(s):  
Juan-Carlos Cheang-Wong ◽  
Ana-Lilia Díaz-Fonseca
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Sol Gel ◽  
Sample Surface ◽  
Electronic Energy ◽  
Titania Nanoparticles ◽  
Direction Parallel ◽  
Titanium Butoxide ◽  
Before And After ◽  
Spherical Silica Particles

AbstractSpherical submicrometer-sized titanium dioxide (TiO2 or titania) particles were prepared by the sol-gel method from hydrolysis and condensation of titanium butoxide Ti(OC4H9)4 using ammonia as a catalyst in ethanol/acetonitrile and annealing in air at 100°C. Subsequently, they were deposited onto silicon substrates, in order to form a monolayer of TiO2 particles. Then these samples were irradiated at room temperature with Si2+ ions at 4, 6 and 8 MeV, with fluences in the 2×1014-2×1015 Si/cm2 range, under an angle of 45° with respect to the sample surface. The titania particles were characterized by scanning electron microscopy to determine their size and shape before and after the ion irradiation. After the Si irradiation the spherical silica particles turned into ellipsoidal particles, as a result of the increase of the particle dimension perpendicular to the ion beam and the decrease in the direction parallel to the ion beam. This deformation effect increases monotonically with the ion fluence, and depends on the electronic energy loss of the impinging ion.

Effects of Ga-Irradiation On Properties of Materials Processed by A Focused Ion Beam (FIB)

2000 ◽  
Vol 647 ◽  
Author(s):  
H. D. Wanzenboeck ◽  
H. Langfischer ◽  
A. Lugstein ◽  
E. Bertagnolli ◽  
U. Grabner ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Cross Sections ◽  
Vapor Deposition ◽  
Focused Ion Beam ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Sample Surface ◽  
Deposition Process ◽  
Microelectronic Devices

AbstractFocused Ion Beam (FIB) technology allows to process various materials within a lateral range below 100 nm. The feasibility to mechanically sputter as well as to direct-write nanostructures and the fact that Ga-ions are utilized is unique for this method. The focused Ga-ions are used to locally induce a chemical vapor deposition of volatile precursor molecules adsorbed on a surface. Local deposition of metals and dielectrics has been achieved on a sub-µm scale utilizing a focused ion beam. This method is highly suitable for advanced microelectronic semiconductor fabrication. However, material specifications are narrow for these tailor-made applications. The effect of the Ga-ions implanted into the material both during sputtering and deposition has been realized as a key parameter for the function of FIB processed microelectronic devices. For Si-based semiconductors Ga can be used as dopant intentionally implanted into a Si substrate to locally modify the conductivity of Si. The results of locally confined ion irradiation on the surface roughness of a Si surface have been exploited by atomic force microscopy (AFM). Both local sputter depletion of the sample surface as well as sub-µm deposition of selected metals or dielectrics by ion-induced chemical vapor deposition (CVD) has been examined. The penetration depth and the distribution of Ga ions during the deposition process have been studied by simulation and experimentally by profiling with secondary ion mass spectroscopy (SIMS). Transmission Electron Microscopy (TEM) of cross-sections of the ion processed materials has revealed amorphisation of the crystalline substrate. For focused ion beam assisted deposition the effects of ion irradiation on the interface to the substrate and the local efficiency of the deposition are illustrated and discussed. The prospects of focused ion beam processing for modification of microelectronic devices in the sub-µm range and the limitations are demonstrated by the examples shown.

Characterization of MeV Ion-Irradiated SiCf/SiC Composites Prepared with Different Methods

2008 ◽  
Vol 59 ◽  
pp. 257-262 ◽  
Author(s):  
Ji Yeon Park ◽  
Seok Min Kang ◽  
Weon Ju Kim ◽  
Akira Kohyama
Keyword(s):  
Hot Pressing ◽  
Focused Ion Beam ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
Irradiation Effect ◽  
Nano Indentation ◽  
Sic Composites

To estimate the ion-irradiation effect on various types of SiCf/SiC composites, a silicon self-ion irradiation was performed at temperatures of 600 °C and 1200 °C and at doses of 5 dpa and 20 dpa, respectively. These SiCf/SiC composites were prepared by different processes such as CVI (chemical vapor infiltration), WA-CVI (SiC whisker assisted CVI) and hot-pressing (HP) method. Hardness was measured by a nano-indentation tester and microstructural changes were observed by TEM with SAD(selected area diffraction) technique for the specimens prepared by FIB (Focused Ion Beam) milling. The damage dose was calculated by the SRIM2003 code and then compared with microstructureal observation.

Analysis of Voltage Contrast in Secondary Electron Images Using a High-Energy Electron Spectrometer

2019 ◽  
Author(s):  
Natsuko Asano ◽  
Shunsuke Asahina ◽  
Natasha Erdman
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Sample Surface ◽  
High Energy ◽  
Secondary Electrons ◽  
Analysis Technique ◽  
Quantitative Understanding ◽  
Voltage Contrast ◽  
Acceleration Voltage ◽  
Failure Localization

Abstract Voltage contrast (VC) observation using a scanning electron microscope (SEM) or a focused ion beam (FIB) is a common failure analysis technique for semiconductor devices.[1] The VC information allows understanding of failure localization issues. In general, VC images are acquired using secondary electrons (SEs) from a sample surface at an acceleration voltage of 0.8–2.0 kV in SEM. In this study, we aimed to find an optimized electron energy range for VC acquisition using Auger electron spectroscopy (AES) for quantitative understanding.

Doping Study on Maskless Selective Direct Growth of GaAs Using Low-Energy Focused Ion Beam

2004 ◽  
Vol 43 (No. 6A) ◽  
pp. L716-L718 ◽  
Author(s):  
Tomokazu Nishiyama ◽  
Eum-Mi Kim ◽  
Kazutoshi Numata ◽  
Kangsa Pak
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Low Energy ◽  
Direct Growth

scholarly journals Effect of Ion Irradiation on Nanoindentation Fracture and Deformation in Silicon Carbide

JOM ◽  
2021 ◽  
Author(s):  
Alexander J. Leide ◽  
Richard I. Todd ◽  
David E. J. Armstrong
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Residual Stresses ◽  
Focused Ion Beam ◽  
Electron Backscatter Diffraction ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Resolution Electron ◽  
Radiation Induced ◽  
Compressive Residual Stresses

AbstractSilicon carbide is desirable for many nuclear applications, making it necessary to understand how it deforms after irradiation. Ion implantation combined with nanoindentation is commonly used to measure radiation-induced changes to mechanical properties; hardness and modulus can be calculated from load–displacement curves, and fracture toughness can be estimated from surface crack lengths. Further insight into indentation deformation and fracture is required to understand the observed changes to mechanical properties caused by irradiation. This paper investigates indentation deformation using high-resolution electron backscatter diffraction (HR-EBSD) and Raman spectroscopy. Significant differences exist after irradiation: fracture is suppressed by swelling-induced compressive residual stresses, and the plastically deformed region extends further from the indentation. During focused ion beam cross-sectioning, indentation cracks grow, and residual stresses are modified. The results clarify the mechanisms responsible for the modification of apparent hardness and apparent indentation toughness values caused by the compressive residual stresses in ion-implanted specimens.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

Study of scalable IBS nanopatterning mechanisms for III-V semiconductors using in-situ surface characterization

2011 ◽  
Vol 1354 ◽  
Author(s):  
Jean Paul Allain ◽  
Osman El-Atwani ◽  
Alex Cimaroli ◽  
Daniel L. Rokusek ◽  
Sami Ortoleva ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Surface Characterization ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Low Energy ◽  
Self Organization ◽  
Beam Parameter ◽  
Ion Beam Sputtering

ABSTRACTIon-beam sputtering (IBS) has been studied as a means for scalable, mask-less nanopatterning of surfaces. Patterning at the nanoscale has been achieved for numerous types of materials including: semiconductors, metals and insulators. Although much work has been focused on tailoring nanopatterning by systematic ion-beam parameter manipulation, limited work has addressed elucidating on the underlying mechanisms for self-organization of multi-component surfaces. In particular there has been little attention to correlate the surface chemistry variation during ion irradiation with the evolution of surface morphology and nanoscale self-organization. Moreover the role of surface impurities on patterning is not well known and characterization during the time-scale of modification remains challenging. This work summarizes an in-situ approach to characterize the evolution of surface chemistry during irradiation and its correlation to surface nanopatterning for a variety of multi-components surfaces. The work highlights the importance and role of surface impurities in nanopatterning of a surface during low-energy ion irradiation. In particular, it shows the importance of irradiation-driven mechanisms in GaSb(100) nanopatterning by low-energy ions and how the study of these systems can be impacted by oxide formation.

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