An Investigation Of Vacancy Population During Arsenic Activation In Silicon

1996 ◽  
Vol 442 ◽  
Author(s):  
O. Dokumaci ◽  
H.-J. Gossmann ◽  
K. S. Jones ◽  
M. E. Law
Keyword(s):  
Arsenic Concentration ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Experimental Investigations ◽  
Excess Vacancy ◽  
Activation Process ◽  
Dislocation Loops ◽  
Plan View ◽  
Sb Doping ◽  
Superlattice Structures

AbstractRecent experimental investigations have shown that electrical deactivation of arsenic in silicon creates excess silicon interstitials. This study investigated the possibility of excess vacancy generation during arsenic activation. We used Sb doping superlattice structures containing six 10 nm wide Sb doped spikes separated by 100 nm. It was found that antimony diffusion was not enhanced as active arsenic concentration increased, indicating there is no observable vacancy injection out of the arsenic layer during the activation process. Plan-view transmission electron microscopy study of the samples revealed dislocation loops before the activation anneal. Although the loops completely dissolved during the activation anneal, they do not seem to be sufficient enough to absorb all the vacancies generated by the activated arsenic. When germanium was present at the surface instead of arsenic, antimony diffusion was enhanced.

Electron Microscopy Study of Fatigue Crack Initiation in Ni3Al Single Crystals

1988 ◽  
Vol 133 ◽  
Author(s):  
L. M. Hsiung ◽  
N. S. Stoloff
Keyword(s):  
Electron Microscopy ◽  
Fatigue Crack ◽  
Crack Initiation ◽  
Single Crystals ◽  
Room Temperature ◽  
Fatigue Crack Initiation ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Dislocation Loops ◽  
Defect Clusters

ABSTRACTTransmission electron microscopy of single-slip oriented Ni3Al single crystals cyclically deformed at room temperature revealed a high density of dislocation dipoles and point defect clusters. The majority of the defect clusters were identified by weak-beam TEM to be of vacancy type. The observations of circular perfect dislocation loops, Frank loops, and spherical voids revealed the evidence of vacancy condensation during fatigue cycling at room temperature. Together with SEM observations of surface topography, it is suggested that fatigue crack initiation in Ni3Al single crystals can be rationalized by formation of microvoids at PSB/matrix interfaces.

In situ annealing of aluminum ion-implanted with molybdenum

1983 ◽  
Vol 41 ◽  
pp. 260-261
Author(s):  
J. Bentley ◽  
L. D. Stephenson ◽  
R. B. Benson ◽  
P. A. Parrish
Keyword(s):  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Naval Research ◽  
Dislocation Network ◽  
Dislocation Loops ◽  
High Concentration ◽  
Aluminum Ion ◽  
Ion Implanted

As part of an analytical electron microscopy study of aluminum ion-implanted with molybdenum, in situ annealing experiments have been performed to better understand the phase transformation mechanisms in material with a peak molybdenum content of approximately 11 at. % Mo. Ion implantations were performed at the Naval Research Laboratory on electropolished coupons 38 × 28 × 0.5 mm of 99.999% Al with 0.5 mm grain size. A dual energy implant schedule of 1.12 × 1020 ions/m2 at 50 keV. plus 1.24 × 1020 ions/m2 at 110 keV was employed. The TEM specimens were prepared by electrodischarge machining 3-mm diameter disks from the implanted coupons and backthinning by electropolishing. In situ annealing was performed in a Philips EM 400T/FEG with the use of a Philips single-tilt heating holder. Videotape recordings were made from the TEM fluorescent viewing screen in the tilted position.A high concentration of small dislocation loops and possibly a tangled dislocation network were present in the as-implanted material. No precipitates were observed; this is consistent with a supersaturated solid solution.

Formation and microstructural development of TiSi2 in (111)Si by Ti ion implantation and annealing at 950 °C

1995 ◽  
Vol 10 (4) ◽  
pp. 891-899 ◽  
Author(s):  
S. Jin ◽  
M. Aindow ◽  
Z. Zhang ◽  
L.J. Chen
Keyword(s):  
Amorphous Layer ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Microstructural Development ◽  
Dislocation Loops ◽  
Transmission Electron Microscopy Study ◽  
Crystalline Layer ◽  
Epitaxial Regrowth ◽  
Transmission Electron ◽  
Silicide Growth

A transmission electron microscopy study of the microstructural development for (111)Si wafers implanted with Ti ions and annealed subsequently at 950 °C is presented. The as-implanted wafers have a Ti-rich amorphous layer at the surface with embedded silicides, which correspond to a crystalline form of TiSi2 that has not been reported previously. Below this lies a Ti-lean crystalline layer with extensive radiation damage. The annealed layers have large incoherent islands of C54 TiSi2, with a layered microstructure in the Si between them consisting of twins, then topotaxial silicides, then dislocation loops. It is proposed that this microstructure arises from silicide growth prior to epitaxial regrowth, whereas for the continuous epitaxial films observed previously at lower annealing temperatures, epitaxial regrowth precedes silicide development.

Matrix Damage in Iron

2000 ◽  
Vol 650 ◽  
Author(s):  
A C Nicol ◽  
M L Jenkins ◽  
M A Kirk
Keyword(s):  
Indirect Evidence ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Dislocation Loops ◽  
Image Size ◽  
Weak Beam ◽  
Transmission Electron ◽  
The Matrix ◽  
Beam Transmission ◽  
Matrix Damage

ABSTRACTWe present results of a weak-beam transmission electron microscopy study of “matrix damage” in two nearly-pure irons (designated alloys 1A and 2A) produced by neutron irradiation to a fluence of 0.06 dpa at 280°C. The matrix damage in both materials was found to consist of small (2-6 nm) dislocation loops. About 80 % have Burgers vectors b = a<100>, and the remainder have b = a/2<111>. The loops in alloy 1A have a mean image size dmean = 2.8± 0.1 nm and a mean maximum image size dmax = 4.2± 0.3 nm, while those in 2A have d mean = 3.4± 0.1 nm and d max = 4.5± 0.3 nm. The number densities are about 8.5 × 1021 m−3 in alloy 1A, and 6.6 × 1021 m−3 in 2A. It can be shown that the loops can account for the observed irradiation hardening. At least some loops are stable under thermal annealing to temperatures of at least 430°C. This and other indirect evidence suggests that their nature is interstitial.

Transmission electron microscopy study of (103)-oriented epitaxial SrBi2Nb2O9 films grown on (111) SrTiO3 and (111) SrRuO3/(111) SrTiO3

2001 ◽  
Vol 16 (2) ◽  
pp. 489-502 ◽  
Author(s):  
M. A. Zurbuchen ◽  
J. Lettieri ◽  
Y. Jia ◽  
D. G. Schlom ◽  
S. K. Streiffer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Substrate Surface ◽  
Microscopy Study ◽  
Dark Field ◽  
Electron Microscopy Study ◽  
Cross Sectional ◽  
Plan View ◽  
Transmission Electron ◽  
Second Phases

Portions of the same epitaxial (103)-oriented SrBi2Nb2O9 film grown on (111) SrTiO3 for which we recently reported the highest remanent polarization (Pr) ever achieved in SrBi2Nb2O9 (or SrBi2Ta2O9) films, i.e., Pr = 15.7 μC/cm2, have been characterized microstructurally by plan-view and cross-sectional transmission electron microscopy (TEM) along three orthogonal viewing directions. SrBi2Nb2O9 grows with its c axis tilted 57° from the substrate surface normal in a three-fold twin structure about the substrate [111], with the growth twins' c axes nominally aligned with the three 〈100〉 SrTiO3 directions. (103) SrBi2Nb2O9 films with and without an underlying epitaxial SrRuO3 bottom electrode have been studied. Dark-field TEM imaging over a 12 μm2 area shows no evidence of second phases (crystalline or amorphous). A high density of out-of-phase boundaries exists in the films.

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