Extended Defects in Fe-Implanted InP After Thermal Annealing

1993 ◽  
Vol 316 ◽  
Author(s):  
C. Frigeri ◽  
C. Bocchi ◽  
A. Carnera ◽  
A. Gasparotto ◽  
N. Gambacorti ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Stacking Fault ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Near Surface ◽  
Sample Stacking ◽  
Stacking Fault Tetrahedra ◽  
Crystalline Substrate ◽  
Extrinsic Dislocation ◽  
Recrystallization Front

ABSTRACTThe recovery of the implant-induced damage and the defects present after thermal annealing at 650 °C in Fe-implanted InP have been investigated by TEM, RBS and X-ray diffractometry as a function of the annealing time that was varied betweeen 0.5 and 2 h. The near-surface damaged layer was removed only for annealing times ≥ 1.5 h. The annealed samples contained stacking fault tetrahedra of vacancy type, extrinsic dislocation loops and microdefects. These extended defects were mostly localized in a band corresponding to the region of transition between amorphous top layer and crystalline substrate as was detected in the as-implanted sample. Stacking fault tetrahedra and loops have also been observed before and beyond this band, respectively. Such defects could be due to either shear strains at the recrystallization front or implant-induced point defects.

Contrast From Point Defects in The Infinitesimal Approximation

1980 ◽  
Vol 38 ◽  
pp. 350-351
Author(s):  
L. J. Sykes ◽  
J. J. Hren
Keyword(s):  
Electron Microscope ◽  
Point Defects ◽  
Broad Class ◽  
Stacking Fault ◽  
Crystalline Solids ◽  
Dislocation Loops ◽  
Analytical Expression ◽  
Stacking Fault Tetrahedra

In electron microscope studies of crystalline solids there is a broad class of very small objects which are imaged primarily by strain contrast. Typical examples include: dislocation loops, precipitates, stacking fault tetrahedra and voids. Such objects are very difficult to identify and measure because of the sensitivity of their image to a host of variables and a similarity in their images. A number of attempts have been made to publish contrast rules to help the microscopist sort out certain subclasses of such defects. For example, Ashby and Brown (1963) described semi-quantitative rules to understand small precipitates. Eyre et al. (1979) published a catalog of images for BCC dislocation loops. Katerbau (1976) described an analytical expression to help understand contrast from small defects. There are other publications as well.

Periodic {001} Walls of Defects in Proton-Irradiated Cu and Ni

1986 ◽  
Vol 82 ◽  
Author(s):  
P. Ehrhart ◽  
W. Jäger ◽  
W. Schilling ◽  
F. Dworschak ◽  
Afaf A. Gadalla ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Structure ◽  
Average Concentration ◽  
Stacking Fault ◽  
Dislocation Loops ◽  
Transmission Electron ◽  
Stacking Fault Tetrahedra

ABSTRACTThe evolution of the defect structure in 3 MeV-proton irradiated Cu and Ni has been investigated by transmission electron microscopy and by differential dilatometry. The proton irradiations were performed at T≦100°C up to irradiation doses of 2 dpa. An efficient loss of selfinterstitial atoms at dislocations and a consequently high average concentration of vacancies in clusters is observed starting from rather low fluences. In addition an ordering of the defects in the form of periodic {001} walls with a typical periodicity length of ≈ 60 nm is observed for all equivalent {001} planes. The walls consist of high local concentrations of dislocations, dislocation loops and stacking-fault tetrahedra. The observed formation of periodic arraysof defect walls is considered as an example for a possibly general microstructural phenomenon in metals under irradiation.

Electron microscope image contrast of small dislocation loops and stacking-fault tetrahedra

1979 ◽  
Vol 292 (1397) ◽  
pp. 523-537 ◽  
Keyword(s):  
Electron Microscope ◽  
Numerical Solutions ◽  
Preceding Paper ◽  
Stacking Fault ◽  
Image Contrast ◽  
Dislocation Loops ◽  
Displacement Fields ◽  
Microscope Image ◽  
Stacking Fault Tetrahedra ◽  
Electron Microscope Image

With the use of the method described in the preceding paper (to be referred to subsequently as I) for constructing the displacement fields, the electron microscope image contrast of small dislocation loops and of stacking-fault tetrahedra has been computed from numerical solutions of the Howie-Whelan (1961) equations. The computer-simulated images, displayed in the form of half-tone pictures, have been used to identify the nature and geometry of such defects in ion-irradiated foils. A systematic study of the contrast of small Frank loops in Cu + ion irradiated copper under a wide variety of diffraction conditions is reported. In particular the variations of the contrast of loops edge-on and inclined to the electron beam with the operating Bragg reflexion, the thickness and inclination of the foil, depth of the defect in the foil and deviation from the Bragg-reflecting condition have been studied. Methods of obtaining useful information, such as the diameters of the loops, are suggested. The contrast of stacking-fault tetrahedra, and of non-edge perfect dislocation loops in ion-irradiated molybdenum is also investigated.

Defects and Diffusion in Si+ Implanted GaAs

1993 ◽  
Vol 300 ◽  
Author(s):  
K.S. Jones ◽  
H.G. Robinson ◽  
T.E. Haynes ◽  
M.D. Deal ◽  
C.C. Lee ◽  
...  
Keyword(s):  
Dislocation Loop ◽  
Vacancy Concentration ◽  
Total Concentration ◽  
Time Interval ◽  
Type I ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Extrinsic Dislocation ◽  
Area Of Concern ◽  
And Diffusion

ABSTRACTThe effect of extended defects on the diffusion of ion implanted species is an area of concern in the development of process simulators for GaAs. This study explores the effect of type I extended defects including voids and dislocation loops on the diffusion of Si implanted into GaAs. <100> Semi-insulating GaAs wafers were implanted with 1 × 1014/cm2 Si+ at implant temperatures between -51°C and 80°C and at energies ranging from 20 keV to 200 keV. SIMS results show that the diffusivity of Si decreases with both increasing implant temperature and increasing implant energy. At the same time extrinsic dislocation loop concentrations also increased. For the implant conditions studied, no voids were observed. The diffusion results can only be reconciled with the TEM results if the dislocation loops are behaving in a reactive rather than proactive manner. In other words, the changes in vacancy concentration that are affecting the diffusivity are also affecting the loop concentration. This model is supported by evidence that Si diffusivity is enhanced over the same time interval the dislocation loops are dissolving which is consistent with the loops having a reactive role. It remains unclear whether the existence of loops significantly affects the total concentration of vacancies and thus diffusion by acting as a competing sink.

Defect Control During Epitaxial Regrowth by Rapid Thermal Annealing

1982 ◽  
Vol 13 ◽  
Author(s):  
H. Baumgart ◽  
G. K. Celler ◽  
D. J. Lischner ◽  
McD. Robinson ◽  
T. T. Sheng
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Laser Annealing ◽  
Solid Phase ◽  
Good Control ◽  
Temperature Gradients ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Incoherent Light ◽  
Defect Control

ABSTRACTRapid Thermal Annealing (RTA) with tungsten halogen lamps provides excellent regrowth of silicon layers damaged by ion implantation. In addition to minimizing dopant redistribution, the inherent advantage of this technique is good control of temperature gradients. The latter is instrumental in reducing the density of extended defects in the annealed samples. In contrast, solid phase laser annealing, which involves steep temperature gradients, always leaves interstitial dislocation loops and point defect clusters. We present a comparative study of crystal quality following laser processing and incoherent light annealing as well as furnace annealing of As, P and B ion implanted Si wafers.

Stacking-fault tetrahedra in ion-implanted III-V compounds

1987 ◽  
Vol 45 ◽  
pp. 316-317
Author(s):  
B.C. De Cooman ◽  
S. McKeman ◽  
C.B. Carter
Keyword(s):  
Surface Layer ◽  
Solid Phase ◽  
High Resolution Electron Microscopy ◽  
Stacking Fault ◽  
Dislocation Loops ◽  
Present Contribution ◽  
Stacking Fault Tetrahedra ◽  
Type Layer ◽  
Resolution Electron ◽  
Before And After

The implantation of heavy ions into GaAs for the purpose of obtaining a shallow n-type layer has been studied in detail, The results obtained by Rutherford Backscattering and high-resolution electron microscopy show that the surface layer is amorphized during implantation and that the solid-phase epitactic regrowth gives rise to a surface layer containing a large density of microtwins and stacking faults. No other defects have been reported other than interstitial-type dislocation loops in the implanted material, despite the fact that P-implants in Si had shown that a high density of stacking-fault tetrahedra (SFT) were formed after annealing. The present contribution reviews the major findings obtained during the first observation of SFT in Ga1-xAlxAs/GaAs (x=0.3) superlattices and Ga1-xAlxAs (x=0.3) epilayers grown on (001) GaAs. The material was grown by molecular-beam epitaxy (MBE). The ion energy used was 175kV, the dose was 1015 cm-2 and the Se ions were implanted at room-temperature The specimens were examined before and after a 4 hour anneal at 660°C.

FAULTED DEFECTS AND STACKING-FAULT ENERGY

1967 ◽  
Vol 45 (2) ◽  
pp. 1135-1146 ◽  
Author(s):  
L. M. Clarebrough ◽  
P. Humble ◽  
M. H. Loretto
Keyword(s):  
Direct Methods ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Face Centered Cubic ◽  
Dislocation Loops ◽  
Cubic Metals ◽  
The Third ◽  
Stacking Fault Tetrahedra ◽  
Dislocation Energy ◽  
Face Centered

Four direct methods of obtaining values of stacking-fault energy from observation of faulted defects in pure face-centered cubic metals are discussed. It is shown that there is essential agreement between the method based on the observation of threefold nodes and that based on the observation of triangular Frank dislocation loops and stacking-fault tetrahedra in deformed f.c.c. metals, in the range where both methods are applicable. On the other hand, it is shown that the third method, based on the collapse size of stacking-fault tetrahedra in quenched metals, cannot yield even an upper limit. New experimental results show that the fourth method, based on the annealing rate of faulted loops, is applicable only to metals of high stacking-fault energy and then only if jog nucleation and propagation are not rate controlling; for low stacking-fault energy metals, these factors, together with the dislocation energy, must be considered, and cannot be completely taken into account.

Influence of the Temperature of Implantation on the Morphology of Defects in MeV Implanted GaAs.

1989 ◽  
Vol 147 ◽  
Author(s):  
G. Braunstein ◽  
Samuel Chen ◽  
S.-Tong Lee ◽  
G. Rajeswaran.
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Point Defects ◽  
Room Temperature ◽  
Surface Region ◽  
Amorphous Region ◽  
Liquid Nitrogen Temperature ◽  
Dislocation Loops ◽  
Near Surface ◽  
Epitaxial Regrowth

AbstractWe have studied the influence of the temperature of implantation on the morphology of the defects created during 1-MeV implantation of Si into GaAs, using RBS-channeling and TEM. The annealing behavior of the disorder has also been investigated.Implantation at liquid-nitrogen temperature results in the amorphization of the implanted sample for doses of 2×1014 cm−2 and larger. Subsequent rapid thermal annealing at 900°C for 10 seconds leads to partial epitaxial regrowth of the amorphous layer. Depending on the implantation dose, the regrowth can proceed from both the front and back ends of the amorphous region or only from the deep end of the implanted zone. Nucleation and growth of a polycrystalline phase occurs concurrently, limiting the extent of the epitaxial regrowth. After implantation at room temperature and above, two distinct types of residual defects are observed or inferred: point defect complexes and dislocation loops. Most of the point defects disappear after rapid thermal annealing at temperatures ≥ 700°C. The effect of annealing on the dislocation loops depends on the distance from the surface of the sample. Those in the near surface region disappear upon rapid thermal annealing at 700°C, whereas the loops located deeper in the sample grow in size and begin to anneal out only at temperatures in excess of 900°C. Implantation at temperatures of 200 - 300°C results in a large reduction in the number of residual point defects. Subsequent annealing at 900°C leads to a nearly defect-free surface region and, underneath that, a buried band of partial dislocation loops similar to those observed in the samples implanted at room temperature and subsequently annealed.

Evolution of nucleation sites and bubble precursors in silicon as a function of helium implanted dose

2002 ◽  
Vol 719 ◽  
Author(s):  
Changlong Liu ◽  
R. Delamare ◽  
E. Ntsoenzok ◽  
G. Regula ◽  
B. Pichaud ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Dose Range ◽  
Nuclear Reaction Analysis ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Dose Dependent ◽  
Subsequent Thermal Annealing

Abstract(111) oriented silicon samples were implanted at room temperature with 1.55 MeV 3He ions in the dose range of 5×1015 to 5×1016/cm2. Cross-sectional transmission electron microscopy (XTEM) was used to study the evolution of bubbles and extended defects during subsequent thermal annealing at 800°C and 900°C for 30min. The He desorption from bubbles and bubble precursors was measured by means of nuclear reaction analysis (NRA). TEM observations show that no bubbles were observed in Si implanted at doses lower than 1×1016/cm2, while a well-defined cavity band was formed after implantation at 5×1016/cm2 and subsequent thermal annealing. At the intermediary dose of 2×1016/cm2, however, the evolution of bubbles and extended defects is quite different. The bubbles prefer to nucleate in large planar clusters surrounded by a high density of dislocation loops emerging from them. The clusters of bubbles act as the sources of the dislocation loops. NRA measurements indicate that the He desorption behavior is also dose-dependent. The He desorption is achieved much faster in low dose implanted Si. The results are qualitatively discussed.

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