Energetic Electron Beam Induced Recrystallization of Ion Implantation Damage in Semiconductors

1991 ◽  
Vol 235 ◽  
Author(s):  
M. W. Bench ◽  
I. M. Robertson ◽  
M. A. Kirk
Keyword(s):  
Electron Beam ◽  
Point Defects ◽  
Temperature Effects ◽  
Beam Energy ◽  
Energetic Electron ◽  
Irradiation Temperature ◽  
Crystalline Material ◽  
Implantation Damage ◽  
Transmission Electron ◽  
Threshold Displacement

ABSTRACTIsolated amorphous zones produced in GaAs, GaP, Si, and Ge by the implantation of 50 keV Kr+ or Xe+ ions have been induced to recrystallize under the influence of the electron beam in the transmission electron microscope. This effect has been investigated as a function of electron irradiation temperature and beam energy in the TEM. Temperature effects were investigated through irradiations performed at 30 and 300 K. The electron energies used ranged from 50–300 keV in the 300 K experiments and 200 keV electrons were used at 30 K.Recovery was induced in all of the materials even at electron energies below the threshold displacement energy indicating production of point defects within the crystalline material is not required to induce regrowth. In GaAs and GaP, recovery occurred for all electron energies studied, down to 50 keV. In Si, the beam induced regrowth rate approaches zero at an energy of 80 keV with the recovery rate increasing with increasing electron energy. At 30 K, the 200 keV electron beam induced recrystallization in all cases studied (GaAs, GaP, and Si).

scholarly journals Irradiation temperature effects on the induced point defects in Ge-doped optical fibers.

2017 ◽  
Vol 169 ◽  
pp. 012008
Author(s):  
A. Alessi ◽  
I. Reghioua ◽  
S. Girard ◽  
S. Agnello ◽  
D. Di Francesca ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Point Defects ◽  
Temperature Effects ◽  
Irradiation Temperature

Coupled irradiation-temperature effects on induced point defects in germanosilicate optical fibers

2017 ◽  
Vol 52 (18) ◽  
pp. 10697-10708 ◽  
Author(s):  
A. Alessi ◽  
S. Agnello ◽  
S. Girard ◽  
D. Di Francesca ◽  
I. Reghioua ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Point Defects ◽  
Temperature Effects ◽  
Irradiation Temperature

Low-energy electron beam induced regrowth of isolated amorphous zones in Si and Ge

1996 ◽  
Vol 11 (9) ◽  
pp. 2152-2157 ◽  
Author(s):  
I. Jenčič ◽  
I. M. Robertson
Keyword(s):  
Electron Beam ◽  
Electron Energy ◽  
Room Temperature ◽  
Electronic Excitation ◽  
Crystalline Material ◽  
Low Energy ◽  
Displacement Damage ◽  
Low Energy Electron ◽  
Threshold Displacement ◽  
Displacive Type

Spatially isolated amorphous regions in Si and Ge have been regrown at room temperature by using an electron beam with an energy less than that required to cause displacement damage in crystalline material. The rate at which the zones regrow is a function of the energy of the electron beam. As the electron energy is increased from 25 keV (lowest energy employed), the regrowth rate decreases and reaches a minimum below the threshold displacement voltage. With further increases in the electron energy, the rate again increases. It is suggested that at the lower electron energies this room temperature regrowth process is stimulated by electronic excitation rather than by displacive-type processes.

Ion-Beam and Electron-Beam Induced Amorphization of Berlinite (AIPO4)

1994 ◽  
Vol 373 ◽  
Author(s):  
N. Bordes ◽  
R.C. Ewing
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Low Dose ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Crystalline Material ◽  
Small Areas ◽  
Transmission Electron

AbstractBerlinite (AIPO4) is isostructural with α-quartz. Like α-quartz, berlinite undergoes a pressure-induced amorphization at 15 ±3 GPa; however, upon release of the pressure, unlike α-quartz which remains amorphous, berlinite returns to the original crystalline structure of the single crystal. Berlinite was irradiated with 1.5 MeV Kr+ at temperatures ranging from 20 to 600K. The onset of amorphization was examined by monitoring the electron diffraction pattern by in situ transmission electron microscopy (TEM) at the HVEM-Tandem Facility at Argonne National Laboratory. The berlinite was easily amorphized at 20K at a relatively low dose of 4x1013 ions/cm2 or 0.05 dpa (displacements per atom). The critical amorphization dose increases with the sample temperature. These experiments also showed that the focused electron beam can locally amorphize the berlinite. After these irradiations, berlinite remained amorphous. At 500 °C, berlinite began to recrystallize: small areas of crystalline material appear in the aperiodic matrix. These results suggest that pressure-induced amorphization and ion-beam induced amorphization, in the case of berlinite, are different processes that result in two different aperiodic structural states.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Domain Formation in Synthetic Quartz

1971 ◽  
Vol 29 ◽  
pp. 156-157
Author(s):  
Joseph J. Comer
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Domain Formation ◽  
Synthetic Quartz ◽  
Transmission Electron ◽  
Black Spots ◽  
Diffraction Mode ◽  
Domain Boundaries ◽  
Kikuchi Lines ◽  
Straight Lines

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

Reduction of Specimen Contamination in Electron-Beam Instruments

1976 ◽  
Vol 34 ◽  
pp. 576-577
Author(s):  
G. Lehmpfuhl ◽  
P. J. Smith
Keyword(s):  
Electron Beam ◽  
Cold Trap ◽  
Beam Diameter ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Hydrocarbon Molecules ◽  
Electron Microscopes ◽  
Combination Of Methods ◽  
Convergent Beam ◽  
Very High

Specimens being observed with electron-beam instruments are subject to contamination, which is due to polymerization of hydrocarbon molecules by the beam. This effect becomes more important as the size of the beam is reduced. In convergent-beam studies with a beam diameter of 100 Å, contamination was observed to grow on samples at very high rates. Within a few seconds needles began forming under the beam on both the top and the underside of the sample, at growth rates of 400-500 Å/s, severely limiting the time available for observation. Such contamination could cause serious difficulty in examining a sample with the new scanning transmission electron microscopes, in which the beam is focused to a few angstroms.We have been able to reduce the rate of contamination buildup by a combination of methods: placing an anticontamination cold trap in the sample region, preheating the sample before observation, and irradiating the sample with a large beam before observing it with a small beam.

Effects of High-Energy Ions on Synthetic Quartz

1972 ◽  
Vol 30 ◽  
pp. 544-545
Author(s):  
Joseph J. Comer ◽  
Charles Bergeron ◽  
Lester F. Lowe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
High Energy ◽  
Transmission Electron ◽  
Kikuchi Lines ◽  
High Energy Ions ◽  
Diffraction Patterns ◽  
Dauphiné Twinning ◽  
Beam Damage

Using a Van De Graaff Accelerator thinned specimens were subjected to bombardment by 3 MeV N+ ions to fluences ranging from 4x1013 to 2x1016 ions/cm2. They were then examined by transmission electron microscopy and reflection electron diffraction using a 100 KV electron beam.At the lowest fluence of 4x1013 ions/cm2 diffraction patterns of the specimens contained Kikuchi lines which appeared somewhat broader and more diffuse than those obtained on unirradiated material. No damage could be detected by transmission electron microscopy in unannealed specimens. However, Dauphiné twinning was particularly pronounced after heating to 665°C for one hour and cooling to room temperature. The twins, seen in Fig. 1, were often less than .25 μm in size, smaller than those formed in unirradiated material and present in greater number. The results are in agreement with earlier observations on the effect of electron beam damage on Dauphiné twinning.

Enhanced information from biological materials through technological improvements in cryo-electron microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 788-789
Author(s):  
Marc J.C. de Jong ◽  
Wim M. Busing ◽  
Max T. Otten
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Biological Materials ◽  
Electron Crystallography ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
The Many ◽  
Technological Improvements ◽  
Beam Damage

Biological materials damage rapidly in the electron beam, limiting the amount of information that can be obtained in the transmission electron microscope. The discovery that observation at cryo temperatures strongly reduces beam damage (in addition to making it unnecessaiy to use chemical fixatives, dehydration agents and stains, which introduce artefacts) has given an important step forward to preserving the ‘live’ situation and makes it possible to study the relation between function, chemical composition and morphology.Among the many cryo-applications, the most challenging is perhaps the determination of the atomic structure. Henderson and co-workers were able to determine the structure of the purple membrane by electron crystallography, providing an understanding of the membrane's working as a proton pump. As far as understood at present, the main stumbling block in achieving high resolution appears to be a random movement of atoms or molecules in the specimen within a fraction of a second after exposure to the electron beam, which destroys the highest-resolution detail sought.

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