Defect Evolution During Laser Annealing

2006 ◽  
Vol 912 ◽  
Author(s):  
Susan B. Felch ◽  
Abhilash Mayur ◽  
Vijay Parihar ◽  
Faran Nouri ◽  
Kevin S. Jones ◽  
...  
Keyword(s):  
Laser Annealing ◽  
Annealing Temperature ◽  
Defect Density ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Plan View ◽  
Residual Defect ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Boron Dopant

AbstractImplementation of millisecond annealing requires the identification of the operating conditions for that technique which minimize the residual defects. In addition, possible combinations of low temperature annealing with millisecond annealing could result in minimal residual defects. The samples studied here were implanted with Ge+ pre-amorphization and boron dopant ions and were activated with a scanning laser annealing technique with maximum temperature dwell times of about one millisecond. The laser anneal conditions were varied, along with combinations of spike anneals. The annealed samples were analyzed by plan-view transmission electron microscopy (TEM) to measure the residual defect density and size. The effects of spike temperature, laser annealing temperature, and scan rate will be discussed.

LOW-Temperature Epitaxial Growth of GaAs on Si Substrates by MBE

1992 ◽  
Vol 263 ◽  
Author(s):  
Ting-Yen Chiang ◽  
En-Huery Liu ◽  
Der-Hwa Yiin ◽  
Tri-Rung Yew
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Epitaxial Growth ◽  
Defect Density ◽  
Solution Treatment ◽  
Plan View ◽  
Si Substrates ◽  
Gaas On Si ◽  
Transmission Electron

ABSTRACTThis paper presents results of the low—temperature epitaxial growth of GaAs on Si substrates with orientation 1°—4° off (100) by molecular beam epitaxy (MBE). The epitaxial growth ·is carried out on Si wafers subjected to HF solution treatment by “spin-etch” technique before the wafer is transferred to the entry chamber of MBE system. Methods used for reducing defect density in the epitaxial layers are proposed. The characterization techniques include cross-sectional transmission electron microscopy (XTEM), plan-view transmission electron microscopy, scanning electron microscopy (S EM), and double crystal X-ray diffraction (DCXRD). Epitaxial films with a full width at half—maximum (FWHM) of about 310 arcsec measured by DCXRD are obtained without annealing.-

Direct Formation of C54 Phase on the Basis of C40 TiSi2 and Its Applications in Deep Sub-Micron Technology

2001 ◽  
Vol 670 ◽  
Author(s):  
S. Y. Chen ◽  
Z. X. Shen ◽  
S. Y. Xu ◽  
A. K. See ◽  
L. H. Chan ◽  
...  
Keyword(s):  
Laser Annealing ◽  
Annealing Temperature ◽  
Pulsed Laser ◽  
Phase Growth ◽  
Patterned Wafers ◽  
Pulsed Laser Annealing ◽  
Transmission Electron ◽  
Annealing Step ◽  
Direct Formation ◽  
New Phase

ABSTRACTA simple and novel salicidation process applying pulsed laser annealing as the first annealing step was used to induce TiSi2 formation. Both Raman spectroscopy and transmission electron microscope results confirm the formation of a new phase of Ti disilicide, the pure C40 TiSi2 after laser irradiation. Direct C54 phase growth on the basis of C40 template bypassing the C49 phase is accomplished at the second annealing temperature as low as 600°C. Line width independent formation of the C54 phase was observed on patterned wafers using this salicidation process and “fine line effect” is thus eliminated.

Analysis of Defects in Laser Annealed GaAs

1980 ◽  
Vol 2 ◽  
Author(s):  
John Fletcher ◽  
J. Narayan ◽  
D. H. Lowndes
Keyword(s):  
Laser Annealing ◽  
Laser Energy ◽  
Threshold Energy ◽  
High Dose ◽  
Surface Degradation ◽  
Plan View ◽  
Implantation Damage ◽  
Transmission Electron ◽  
Residual Damage ◽  
Good Agreement

ABSTRACTThe nature and depth distributions of residual damage in ion implanted and pulsed ruby laser annealed GaAs have been studied using both plan-view and cross-section transmission electron microscopy (TEM) specimens for high dose (1.0 × 1015 cm−2) Zn+, Se+ and Mg+ implants. It was found that laser energy densities above 0.36 J/cm2 were required to remove the implantation damage, this threshold energy density giving good agreement with that indicated by electrical activation measurements. Laser induced surface degradation of the GaAs was present even for energy densities as low as 0.25 J/cm2, and more severe damage, with the introduction of dislocations near the surface, was present for energy densities above 0.8 J/cm2. The use of thin SiO2 layers for encapsulation during laser annealing was found to substantially reduce this surface degradation.

Effect of Substrate Misorientation on the Structual Strain and Defect Distribution of Mocvd Grown GaAs on Si

1988 ◽  
Vol 116 ◽  
Author(s):  
K.C. Hsieh ◽  
M.S. Feng ◽  
G.E. Stillman ◽  
C.R. Ito ◽  
D.G. McIntyre ◽  
...  
Keyword(s):  
Defect Density ◽  
Chemical Vapor ◽  
Asymmetric Distribution ◽  
Furnace Annealing ◽  
Double Crystal ◽  
Strain Anisotropy ◽  
Plan View ◽  
Defect Distribution ◽  
Si Substrates ◽  
Transmission Electron

Astract:A systematic study of the structural properties and defect distribution of GaAs layers grown by metalorganic chemical vapor deposition on Si substrates misoriented 1°, 1.5°, 2°, 4°, and 6° from [100] toward [011] is reported. Double crystal x-ray rocking curves, cross-section and plan-view Transmission Electron Microscopy (TEM) are used to characterize the structural strain and defect distribution of as-grown and annealed GaAs layers. Both strain and defect density in the GaAs layers are found to be dependent of the degree of substrate misorientation as well as the direction in which measurements are made. Plan-view TEM shows an asymmetric distribution of microtwins in two perpendicular directions. There exists a correlation between the directionality of the strain and of the defect density. Furnace annealing at 850°C for 30 minutes in an arsine overpressure can reduce significantly the defects, the strain and the strain anisotropy. It is found that microtwins are of the highest density when the substrate is misoriented about 4 degrees for the as-grown samples. Though a reduction of defects after annealing occurs for all samples, the least misoriented one shows the most improvement.

Effect of the Ge preamorphisation dose on the thermal evolution of End of Range defects

2001 ◽  
Vol 669 ◽  
Author(s):  
B. Colombeau ◽  
F. Cristiano ◽  
J-C. Marrot ◽  
G. Ben Assayag ◽  
A. Claverie
Keyword(s):  
Ostwald Ripening ◽  
Defect Density ◽  
Thermal Evolution ◽  
Plan View ◽  
Transmission Electron ◽  
The Matrix ◽  
Mean Size ◽  
Defect Size Distribution ◽  
Increasing Function ◽  
Imaging Conditions

ABSTRACTIn this paper, we study the effect of the Ge+ preamorphisation dose on the thermal evolution of End of Range (EOR) defects upon annealing. Amorphisations were carried out by implanting Ge+ at 150 keV to doses ranging from 1×1015 ions/cm2 to 8×1015ions/cm2. Rapid Thermal Annealing (RTA) was performed for various time/temperature combinations in nitrogen ambient. Plan view transmission electron microscopy under specific imaging conditions was used to measure the size distributions and densities of the EOR defects. We found that for a fixed thermal budget, the increase in the Ge ion dose results in an increase in the defect density but has no effect on the defect size distribution. This invariance of the mean size of defects with respect to the initial supersaturation introduced in the matrix is an expected characteristic of a conservative Ostwald ripening mechanism. Moreover, the total number (Nb) of Si interstitial atoms bound to the EOR defects is a monotonically increasing function of the Ge ion dose. Furthermore, we found that Nb is directly proportional to the number of Si atoms in excess of the vacancies found below the a/c interface as calculated by MonteCarlo simulations. This is consistent with the “excess interstitial” model which explains the origin of the EOR defects.

Defect investigation of GaN thin films etched by photo-electrochemical and hot wet etching by atomic force and transmission electron microscopy

2001 ◽  
Vol 680 ◽  
Author(s):  
P. Visconti ◽  
K. M. Jones ◽  
M. A. Reshchikov ◽  
R. Cingolani ◽  
H. Morkoç ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Density ◽  
Wet Etching ◽  
Hydride Vapor Phase Epitaxy ◽  
Structural Defects ◽  
Accurate Estimation ◽  
Plan View ◽  
Atomic Force ◽  
Transmission Electron

ABSTRACTThe availability of reliable and quick methods to investigate defects in GaN films is of great interest. Photo-electrochemical (PEC), and hot wet etching using both H3PO4 acid and molten KOH have been used to study structural defects in GaN layers grown by hydride vapor phase epitaxy and molecular beam epitaxy. The purpose of this work is to determine whether, and under what conditions, these different methods of investigation are consistent and to get to a more accurate estimation of the defect density. As-grown and etched surfaces were investigated by atomic force microscopy (AFM), and plan-view and cross-sectional transmission electron microscopy (TEM). Free-standing whisker-like features and hexagonal etch pits were formed on the etched sample surfaces by PEC and wet etching, respectively. Using plan-view AFM, we found the density of whiskers (8x108-1×109 cm−2) to be similar to the etch pit densities when etched in both H3PO4 and molten KOH under precise etching conditions. During the wet etching process, a careful balance must be struck to ensure that every defect is delineated, but not overetched to cause merging which would lead to an underestimation of the defect density. Additionally, TEM observations confirmed the dislocation densities obtained by etching, which increased our confidence in the consistency of the methods used.

Interaction Between Co and SiO2 During Ion-Beam Mixing and Rapid Thermal Annealing

1992 ◽  
Vol 260 ◽  
Author(s):  
C. Dehm ◽  
I. Kasko ◽  
E. P. Burte ◽  
H. Ryssel
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Temperature ◽  
Ion Beam ◽  
Ion Beam Mixing ◽  
Plan View ◽  
Implantation Energy ◽  
Transmission Electron ◽  
Co Concentration ◽  
Secondary Ion

ABSTRACTFor the application in self-aligned processes, it was supposed that CoSi2 could be superior to TiSi2, since, unlike Ti, a reaction between Co and SiO2 was not observed up to now. We studied the reaction of Co and SiO2 during ion-beam mixing and rapid thermal annealing (RTA). The influences of As and Ge implantation energy and dose were investigated in the range of 50 to 200 keV and 1–1014 to 5–1015 cm2. The annealing temperature was varied between 700° C and 1100°C.It could be demonstrated that the Co concentration in SiO2 rises with increasing Ge and As energy and dose up to values of 5·1015 cm2 compared to 2·1012 cm2 in unim-planted, annealed samples. The Co profiles in SiO2 were also studied by secondary ion mass spectroscopy (SIMS) and compared with Monte-Carlo simulations indicating pure ballistic mixing. Plan-view and cross-section transmission electron microscopy (TEM) were used to examine the SiO2 surface as well as the Co-SiO2 interface. These investigations revealed that ion-beam mixing with doses at or above 5·1014 cm2 and subsequent annealing does not damage the SiO2 unlike to unimplanted, annealed samples which show a rather severe structural change of the SiO2 surface increasing with rising annealing temperatures.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

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