Implant Damage in AlGaAs Based Superlattices and Alloys at 77K

1989 ◽  
Vol 147 ◽  
Author(s):  
E. A. Dobisz ◽  
H. Dietrich ◽  
A. W. McCormick ◽  
J. P. Harbison
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Layer Thickness ◽  
Room Temperature ◽  
Amorphous Layer ◽  
Current Work ◽  
Cross Sectional ◽  
Bulk Gaas ◽  
Transmission Electron ◽  
Extensive Damage

AbstractPreviously, it was shown that superlattices implanted with Si at 77K, exhibited more extensive damage and uniform compositional mixing upon subsequent annealing than samples implanted at room temperature.[l,2] The current work focuses on the damage in samples implanted with Si at 77K. The study shows that for a given dose, the amount of damage depends upon the layer thickness and the composition. Specimens of bulk GaAs, Al 3Ga. 7As, 7.5 nm GaAs -10 nm Al. 3Ga. 7As superlattice (SL1), 5.5 nm GaAs −3.5 nm AlAs superlattice (SL2), and 8.0 nm GaAs −8.0 nm AlAs superlat-tice (SL3) were implanted at 77K with 100 KeV Si, with doses ranging from 3 × 1013 cm−2 to 1 × 1015 cm−2. The samples were examined by ion channelling and cross sectional transmission electron microscopy (TEM). At 77K and a dose of 1 × 1014 cm−2, the GaAs and SLi showed an amorphous layer, while no damage peak was observed in SL2. The 77K amorphization thresholds of the Al 3Ga. 7As alloy, SL2, and SL3 were 2.5 × 1014 cm−2, 4 × 1014 cm−2, and 1 × 1015 cm−2 respectively. The sharpness of the amorphization threshold varied with the material.

High Resolution Transmission Electron Microscopy of Proton Implanted Gallium Arsenide

1985 ◽  
Vol 46 ◽  
Author(s):  
D. K. Sadana ◽  
J. M. Zavada ◽  
H. A. Jenkinson ◽  
T. Sands
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Phenomenological Model ◽  
Room Temperature ◽  
Stacking Faults ◽  
High Dose ◽  
Cross Sectional ◽  
Projected Range ◽  
Transmission Electron

AbstractHigh resolution transmission electron microscopy (HRTEM) has been performed on cross-sectional specimens from high dose (1016 cm−2) H+ implanted (100) GaAs (300 keV at room temperature). It was found that annealing at 500°C created small (20-50Å) loops on {111} near the projected range (Rp)(3.2 μm). At 550-600°C, voids surrounded by stacking faults, microtwins and perfect dislocations were observed near the Rp. A phenomenological model explaining the observed results is proposed.

Effects of Implant Temperature on Disordering of AlAs-GaAs Superlattices

1986 ◽  
Vol 77 ◽  
Author(s):  
E. A. Dobisz ◽  
B. Tell ◽  
H. G. Craighead ◽  
S. A. Schwarz ◽  
M. C. Tamargo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Sectional ◽  
Bulk Gaas ◽  
Directional Diffusion ◽  
Transmission Electron ◽  
Silicon Impurity ◽  
Secondary Ion ◽  
Mass Spectro ◽  
Superlattice Period

ABSTRACTThe effect of implant temperature, superlattice period, and directional diffusion has been studied for silicon impurity-enhanced compositional disordering of GaAs-AlAs superlattices (SL) of 9 ran and 16 nm period. The SL were implanted with Si at temperatures of 483 K, 293 K, and 77 K, with an energy of 100 keV and dose of 2.5 × 1014 cm-2. These were examined by cross-sectional transmission electron microscopy and secondary ion mass spectro-scopy for structural and compositional information. The damage due to implantation prior to annealing is strikingly less for superlattices than for bulk GaAs. All annealed samples exhibited disordering, with the 9 nm period SL exhibiting a deeper disordered region than the 16 nm SL. The greatest enhancement was found in the 9 nm period SL implanted at 77 K, in which the disordering extended from a depth of 25 nm to =300 nm. The mixing was found to be anisotropie, with the SL mixing propagating greater in depth than in the lateral directions. The result has important implications for high resolution patterning possibilities with this method.

A Transmission Electron Microscopy Study of the Effect of Interfaces on Bubble Formation in He-Implanted Cu-Nb Multilayers

2012 ◽  
Vol 18 (1) ◽  
pp. 152-161 ◽  
Author(s):  
D. Bhattacharyya ◽  
M.J. Demkowicz ◽  
Y.-Q. Wang ◽  
R.E. Baumer ◽  
M. Nastasi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Layer Thickness ◽  
Bubble Diameter ◽  
Bubble Formation ◽  
Nuclear Reaction Analysis ◽  
Cross Sectional ◽  
Helium Bubbles ◽  
Transmission Electron ◽  
Pure Cu

AbstractMagnetron sputtered thin films of Cu, Nb, and Cu-Nb multilayers with 2.5 and 5 nm nominal layer thickness were deposited on Si and implanted with 4He+ and 3He+ ions. Secondary ion mass spectroscopy and nuclear reaction analysis, respectively, were used to measure the 4He+ and 3He+ concentration profile with depth inside the films. Cross-sectional transmission electron microscopy was used to characterize the helium bubbles. Analysis of the contrast from helium bubbles in defocused transmission electron microscope images showed a minimum bubble diameter of 1.25 nm. While pure Cu and Nb films showed bubble contrast over the entire range of helium implantation, the multilayers exhibited bubbles only above a critical He concentration that increased almost linearly with decreasing layer thickness. The work shows that large amounts of helium can be trapped at incoherent interfaces in the form of stable, nanometer-size bubbles.

Growth of Epitaxial CoSi2/Si Multilayers

1986 ◽  
Vol 77 ◽  
Author(s):  
B. D. Runt ◽  
N. Lewis ◽  
L. J. Schotalter ◽  
E. L. Hall ◽  
L. G. Turner
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Solid Phase ◽  
Multilayer Structures ◽  
Solid Phase Epitaxy ◽  
Cross Sectional ◽  
Temperature Growth ◽  
Transmission Electron

ABSTRACTEpitaxial CoSi2/Si multilayers have been grown on Si(111) substrates with up to four bilayers of suicide and Si. To our knowledge, these are the first reported epitaxial metal-semiconductor multilayer structures. The growth of these heterostructures is complicated by pinhole formation in the suicide layers and by nonuniform growth of Si over the suicide films, but these problems can be controlled through nse of proper growth techniques. CoSi2 pinhole formation has been significantly reduced by utilizing a novel solid phase epitaxy technique in which room-temperature-deposited Co/Si bilayers are annealed to 600–650δC to form the suicide layers. Islanding in the Si layers is minimized by depositing a thin (<100Å) Si layer at room temperature with subsequent high temperature growth of the remainder of the Si. Cross-sectional transmission electron microscopy studies demonstrate that these growth procedures dramatically improve the continuity and quality of the CoSi. and Si multilayers.

On Nature of Resonant Transversal Kerr Effect in InMnAs and GaMnAs Layers

2010 ◽  
Vol 168-169 ◽  
pp. 35-38 ◽  
Author(s):  
E.A. Gan'shina ◽  
L.L. Golik ◽  
V.I. Kovalev ◽  
Z.E. Kun’kova ◽  
M.P. Temiryazeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Properties ◽  
Laser Ablation ◽  
Kerr Effect ◽  
Room Temperature ◽  
Optical Constants ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Resonant Character

Optical and magneto-optical properties of In(Ga)MnAs layers fabricated by laser ablation on GaAs(100) substrates were studied. Spectra of the optical constants and the transversal Kerr effect (TKE) depended substantially on the conditions of layer fabrication and testified to the presence of MnAs inclusions in all the samples. The cross-sectional transmission electron microscopy revealed the presence in the layers of inclusions 10-40 nm in size. At room temperature, a strong resonant band was observed in the TKE spectra of some In(Ga)MnAs layers in the energy range 0.5-2.7 eV. The resonant character of the TKE spectra was explained by excitation of surface plasmons in the MnAs nanoclusters embedded in the semiconductor host.

Oxidation and crystallization of an amorphous Zr60Al15Ni25 alloy

1996 ◽  
Vol 11 (11) ◽  
pp. 2738-2743 ◽  
Author(s):  
X. Sun ◽  
S. Schneider ◽  
U. Geyer ◽  
W. L. Johnson ◽  
M-A. Nicolet
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Amorphous Alloy ◽  
Oxidation Process ◽  
Amorphous Layer ◽  
Intermetallic Phases ◽  
Annealing Duration ◽  
Oxide Layer Thickness ◽  
Cross Sectional ◽  
Transmission Electron

The amorphous ternary metallic alloy Zr60Al15Ni25 was oxidized in dry oxygen in the temperature range 310 °C to 410 °C. Rutherford backscattering (RBS) and cross-sectional transmission electron microscopy (TEM) studies suggest that during this treatment an amorphous layer of zirconium-aluminum-oxide is formed at the surface. Nickel was depleted in the oxide and enriched in the amorphous alloy near the interface. The oxide layer thickness grows parabolically with annealing duration, with a transport constant of 2.8 × 10−5 m2/s × exp(−1.7 eV/kT). The oxidation rate may be controlled by the diffusion of Ni in the amorphous alloy. At later stages of the oxidation process, precipitates of nanocrystalline ZrO2 appear in the oxide near the interface. Finally, two intermetallic phases nucleate and grow simultaneously in the alloy, one at the interface and one within the alloy. An explanation involving preferential oxidation is proposed.

Role of Implant Energy on Defect Structures for Phosphorus Implanted Silicon

1986 ◽  
Vol 71 ◽  
Author(s):  
S. Prussin ◽  
Kevin S. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Range ◽  
Amorphous Layer ◽  
The Other ◽  
Defect Structures ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Good Contact

AbstractA series of 18 wafers were implanted with phosphorus ions covering an energy range of 25 to 180 keV at a dose of 1 × 1015 cm−2 using a Waycool end station which provides good contact between the wafers and a thermal sink. Half the wafers had {100} surfaces and the other half {111} surfaces. The morphology of the as-implanted surface, defined by the thickness of the amorphous layer and whether that layer was submerged or lay at the surface, was affected by implant energy and surface orientation. After a 550°C regrowth and an activation anneal of 30 minutes at 900°C, the defect structures were evaluated by plan and cross-sectional transmission electron microscopy. A dear correlation was found between the implant morphology, the wafer orientation, and the defect structures.

THE EXCHANGE-BIASING IN THE TOP-CONFIGURATION Ni80Fe20/Ir20Mn80 SYSTEM

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1658-1662
Author(s):  
YUAN-TSUNG CHEN
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Cross Sectional ◽  
X Ray ◽  
Exchange Biasing ◽  
Plane Field ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Optimal Values

In this work, top-configuration exchange-biasing NiFe ( y )/ IrMn (90Å) systems have been investigated with three different conditions: (a) the substrate temperature ( T s ) was kept at room temperature (RT) only, (b) T s at RT with an in-plane field ( h ) = 500 Oe deposition during deposition, and (c) T s = RT with h during deposition and postdeposition annealing in the field at T A = 250° C for 1h, with the samples field cooled to RT. High resolution electron cross-sectional transmission electron microscopy (HR X-TEM) and x-ray results reveal that the IrMn (111) texturing plays a key role in the exchange-biasing field ( H ex ) and interfacial energy ( J k ). The H ex versus y result shows that H ex increases when y decreases. Since J k = H ex M s y , where M s is NiFe magnetization, it is easy to derive H ex = J k /( M s y ). Therefore, if H ex is inversely proportional to y , with J k / M s constant, we find H ex y = constant. In short, the y dependence of J k is similar to that of M s for each curve. The H c is inversely proportional to y because of the surface pinning effects from the Ta / NiFe and NiFe / IrMn interfaces. Finally, the optimal values for H ex and J k are 220 Oe and 0.075 erg/cm2, respectively.

The Role of Ion Mass on End-of-Range Damage in Shallow Preamorphizing Silicon

2001 ◽  
Vol 669 ◽  
Author(s):  
Mark H. Clark ◽  
Kevin S. Jones ◽  
Tony E. Haynes ◽  
Charles J. Barbour ◽  
Kenneth G. Minor ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Amorphous Layer ◽  
Cross Sectional ◽  
Plan View ◽  
Enhanced Diffusion ◽  
Transmission Electron ◽  
Marker Layer ◽  
Process Simulator

ABSTRACTPreamorphization is commonly used to form shallow junction in silicon CMOS devices. The purposeof this experiment was to study the effect of the preamorphizing species' mass on the interstitial concentration at the end-of-range (EOR). Isovalent species of Si, Ge, Sn and Pb were compared. Silicon wafers with a buried boron marker layer (4700 Å deep) were amorphized using implants of 22 keV 28Si+, 32 keV73Ge+, 40 keV 119Sn+ or 45 keV 207Pb+, which resulted in similar amorphous layer depths. All species were implanted at a dose of 5×1014 /cm2. Cross-sectional transmission electron microscopy (XTEM) was used tomeasure amorphous layer depths (approximately 400 Å). Post-implantation anneals were performed at 750 °C for 15 minutes. Plan-view transmission electron microscopy (PTEM) was used to observe and quantify the EOR defect population upon annealing. Secondary ion mass spectrometry (SIMS) was used to monitor the transient enhanced diffusion (TED) of the buried boron marker layer resulting from the EOR damage introduced by the amorphizing implants. Based upon the SIMS results Florida Object Oriented Process Simulator (FLOOPS) calculated the resulting time average diffusivity enhancements. Results showed that increasing the ion mass over a significant range (28 to 207 AMU) not only affects the quantity and type of damage that occurs at the EOR, but results in a reduced diffusivity enhancement.

Scanning and Transmission Electron Microscopy of Human Red Blood Cells

1969 ◽  
Vol 27 ◽  
pp. 44-45
Author(s):  
A.J. Tousimis ◽  
T.R. Padden
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Blood Cells ◽  
Room Temperature ◽  
Type Specimen ◽  
New Combination ◽  
Human Red Blood Cells ◽  
Transmission Electron ◽  
Microscope Slides ◽  
Scanning Electron

The size, shape and surface morphology of human erythrocytes (RBC) were examined by scanning electron microscopy (SEM), of the fixed material directly and by transmission electron microscopy (TEM) of surface replicas to compare the relative merits of these two observational procedures for this type specimen.A sample of human blood was fixed in glutaraldehyde and washed in distilled water by centrifugation. The washed RBC's were spread on freshly cleaved mica and on aluminum coated microscope slides and then air dried at room temperature. The SEM specimens were rotary coated with 150Å of 60:40- gold:palladium alloy in a vacuum evaporator using a new combination spinning and tilting device. The TEM specimens were preshadowed with platinum and then rotary coated with carbon in the same device. After stripping the RBC-Pt-C composite film, the RBC's were dissolved in 2.5N HNO3 followed by 0.2N NaOH leaving the preshadowed surface replicas showing positive topography.

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