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

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.

2006 ◽  
Vol 957 ◽  
Author(s):  
Rajendra Singh ◽  
R. Scholz ◽  
U. Gösele ◽  
S. H. Christiansen

ABSTRACTZnO(0001) bulk crystals were implanted with 100 keV H2+ ions with various doses in the range of 5×1016 to 3×1017 cm-2. The ZnO crystals implanted up to a dose of 2.2×1017 cm-2 did not show any surface exfoliation, even after post-implantation annealing at temperatures up to 800°C for 1 h while those crystals implanted with a dose of 2.8×1017 cm-2 or higher exhibited exfoliated surfaces already in the as-implanted state. In a narrow dose window in between, controlled exfoliation could be obtained upon post-implantation annealing only. Cross-sectional transmission electron microscopy (XTEM) of the implanted ZnO samples showed that a large number of nanovoids were formed within the implantation-induced damage band. These nanovoids served as precursors for the formation of microcracks leading to the exfoliation of ZnO wafer surfaces. In addition to the nanovoids, elongated nanocolumns perpendicular to the ZnO wafer surfaces were also observed. These nanocolumns showed diameters of up to 10 nm and lengths of up to 500 nm. The nanocolumns were found in the ZnO wafer even well beyond the projected range of hydrogen ions.


1994 ◽  
Vol 357 ◽  
Author(s):  
A. J. Pedraza ◽  
Siqi Cao ◽  
L. F. Allard ◽  
D. H. Lowndes

AbstractA near-surface thin layer is melted when single crystal alumina (sapphire) is pulsed laserirradiated in an Ar-4%H2 atmosphere. γ-alumina grows epitaxially from the (0001) face of axalumina (sapphire) during the rapid solidification of this layer that occurs once the laser pulse is over. Cross sectional high resolution transmission electron microscopy (HRTEM) reveals that the interface between unmelted sapphire and γ-alumina is atomistically flat with steps of one to a few close-packed oxygen layers; however, pronounced lattice distortions exist in the resolidified γ-alumina. HRTEM also is used to study the metal-ceramic interface of a copper film deposited on a laser-irradiated alumina substrate. The observed changes of the interfacial structure relative to that of unexposed substrates are correlated with the strong enhancement of film-substrate bonding promoted by laser irradiation. HRTEM shows that a thin amorphous film is produced after irradiation of 99.6% polycrystalline alumina. Formation of a diffuse interface and atomic rearrangements that can take place in metastable phases contribute to enhance the bonding strength of copper to laser-irradiated alumina.


2010 ◽  
Vol 09 (01n02) ◽  
pp. 75-81
Author(s):  
L. Z. PEI ◽  
H. S. ZHAO ◽  
H. Y. YU ◽  
J. L. HU

Hollow germanium tubular nanostructures have been obtained by a hydrothermal process at a temperature of 400°C and pressure of 7 MPa with quick cooling to room temperature. Transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) show that the germanium tubular nanostructures are polycrystalline and have open-end structures at the tips. The diameter of germanium tubular nanostructures is about 40–70 nm and the inner pore size is about 10 nm in average. We propose the rolling mechanism for the formation of tubular nanostructures from lamellar nanostructures to explain the possible formation process of germanium tubular nanostructures.


2004 ◽  
Vol 810 ◽  
Author(s):  
H.B. Yao ◽  
D.Z. Chi ◽  
S. Tripathy ◽  
S.Y. Chow ◽  
W.D. Wang ◽  
...  

ABSTRACTThe germanosilicidation of Ni on strained (001) Si0.8Ge0.2, particularly Ge segregation, grain boundary grooving, and surface morphology, during rapid thermal annealing (RTA) was studied. High-resolution cross-sectional transmission electron microscopy (HRXTEM) suggested that Ge-rich Si1−zGez segregation takes place preferentially at the germanosilicide/Si1−xGex interface, more specifically at the triple junctions between two adjacent NiSi1−uGeu grains and the underlying epi Si1−xGex, and it is accompanied with thermal grooving process. The segregation process accelerates the thermal grooving of NiSi1−uGeu grain boundaries at the interface. The segregation-accelerated grain boundary grooving has significant effect on the surface morphology of NiSi1−uGeu films in Ni-SiGe system.


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