In Situ Study of the Temperature Dependence of Irradiation-Induced Amorphization in A-Sic

1995 ◽  
Vol 398 ◽  
Author(s):  
W. J. Weber ◽  
L. M. Wang ◽  
N. Yu ◽  
N. J. Hess
Keyword(s):  
Damage Accumulation ◽  
Ion Beam ◽  
Amorphous State ◽  
Damage Level ◽  
Ion Channeling ◽  
In Situ Study ◽  
Recovery Processes ◽  
Dual Beam ◽  
Two Stages

ABSTRACTIon-beam-induced amorphization in single crystal α-SiC has been studied as a function of temperature. Specimens have been irradiated with 1.5 MeV Xe+ ions over the temperature range from 20 to 475 K using the HVEM-Tandem Facility (ANL), and the evolution of the amorphous state has been followed in situ in the HVEM. Specimens also have been irradiated at 170, 300, and 370 K with 360 keV Ar+ ions, and the damage accumulation process followed in situ by Rutherford backscattering spectroscopy/channeling using the dual beam facilities at the Ion Beam Materials Laboratory (LANL). At 20 K, the displacement dose for complete amorphization is 0.25 dpa and increases with temperature in two stages. The activation energy associated with the simultaneous recovery processes above 100 K is 0.12 ± 0.02 eV. The critical temperature above which amorphization does not occur is 485 K under the 1.5 MeV Xe+ irradiation conditions. Ion channeling results suggest that the rate of simultaneous recovery increases with temperature only above a critical damage level. Raman spectroscopy indicates that rapid chemical disordering occurs during irradiation.

To Eliminate Curtain Effect of FIB TEM Samples by a Combination of Sample Dicing and Backside Milling

2014 ◽  
Author(s):  
Jian-Shing Luo ◽  
Hsiu Ting Lee
Keyword(s):  
Sample Preparation ◽  
Focused Ion Beam ◽  
Preparation Method ◽  
Low Cost ◽  
Ion Beam ◽  
Sample Preparation Method ◽  
Site Specific ◽  
Dual Beam ◽  
Transmission Electron

Abstract Several methods are used to invert samples 180 deg in a dual beam focused ion beam (FIB) system for backside milling by a specific in-situ lift out system or stages. However, most of those methods occupied too much time on FIB systems or requires a specific in-situ lift out system. This paper provides a novel transmission electron microscopy (TEM) sample preparation method to eliminate the curtain effect completely by a combination of backside milling and sample dicing with low cost and less FIB time. The procedures of the TEM pre-thinned sample preparation method using a combination of sample dicing and backside milling are described step by step. From the analysis results, the method has applied successfully to eliminate the curtain effect of dual beam FIB TEM samples for both random and site specific addresses.

In-Situ Dual Beam (FIBSEM) Techniques for Probe Pad Deposition and Dielectric Integrity Inspection in 0.2 μm Technology DRAM Single Cells

1999 ◽  
Author(s):  
Gunnar Zimmermann ◽  
Richard Chapman
Keyword(s):  
Electron Beam ◽  
Single Cell ◽  
Single Cells ◽  
Ion Beam ◽  
Gate Oxide ◽  
Ion Milling ◽  
Dual Beam ◽  
Sem Imaging ◽  
Innovative Techniques

Abstract Dual beam FIBSEM systems invite the use of innovative techniques to localize IC fails both electrically and physically. For electrical localization, we present a quick and reliable in-situ FIBSEM technique to deposit probe pads with very low parasitic leakage (Ipara < 4E-11A at 3V). The probe pads were Pt, deposited with ion beam assistance, on top of highly insulating SiOx, deposited with electron beam assistance. The buried plate (n-Band), p-well, wordline and bitline of a failing and a good 0.2 μm technology DRAM single cell were contacted. Both cells shared the same wordline for direct comparison of cell characteristics. Through this technique we electrically isolated the fail to a single cell by detecting leakage between the polysilicon wordline gate and the cell diffusion. For physical localization, we present a completely in-situ FIBSEM technique that combines ion milling, XeF2 staining and SEM imaging. With this technique, the electrically isolated fail was found to be a hole in the gate oxide at the bad cell.

The Complementary Nature of Electron Microscopy and ION Channeling for the Assessment of Radiation Damage Evolution in Ceramics

1998 ◽  
Vol 4 (S2) ◽  
pp. 558-559
Author(s):  
K. E. Sickafus
Keyword(s):  
Damage Evolution ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Quantitative Measure ◽  
Heavy Ion ◽  
Damage Parameter ◽  
Irradiation Damage ◽  
Damage Level ◽  
Ion Channeling ◽  
Typical Experiment

In ion irradiation damage studies on ceramics, damage evolution is often assessed using Rutherford backscattering spectroscopy and ion channeling (RBS/C) techniques. In a typical experiment, a single crystal ceramic sample is irradiated with heavy ions and then the crystal is exposed to He ions along a low-index crystallographic orientation. Simultaneously, the backscattered He ion yield is measured as a function of ion energy loss. For He ions scattered from the heavy ion irradiated volume, the He ion yield increases in proportion to the heavy ion dose. The RBS/C yield rises because the He ion beam is dechanneled by, for instance, interstitial point defects and clusters and their associated strain fields. A quantitative measure of dechanneling is denoted by χmin, defined as the ratio of the He ion yield along a low-index crystal orientation, to the yield obtained in a random (non-channeling) orientation. The damage parameter xmin varies from 0 to 1, where 1 represents the maximum damage level that can be measured by RBS/C.

scholarly journals Origin of the Difference in the Resistivity of As-Grown Focused-Ion- and Focused-Electron-Beam-Induced Pt Nanodeposits

2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
J. M. De Teresa ◽  
R. Córdoba ◽  
A. Fernández-Pacheco ◽  
O. Montero ◽  
P. Strichovanec ◽  
...  
Keyword(s):  
Voltage Dependence ◽  
Ion Beam ◽  
Carbon Matrix ◽  
Ex Situ ◽  
Semiconducting Materials ◽  
Dual Beam ◽  
Transmission Electron ◽  
The Difference ◽  
Main Component

We study the origin of the strong difference in the resistivity of focused-electron- and focused-Ga-ion-beam-induced deposition (FEBID and FIBID, resp.) of Pt performed in a dual beam equipment using(CH3)3Pt(CpCH3)as the precursor gas. We have performed in-situ and ex-situ resistance measurements in both types of nanodeposits, finding that the resistivity of Pt by FEBID is typically four orders of magnitude higher than Pt by FIBID. In the case of Pt by FEBID, the current-versus-voltage dependence is nonlinear and the resistance-versus-temperature behavior is strongly semiconducting, whereas Pt by FIBID shows linear current-versus-voltage dependence and only slight temperature dependence. The microstructure, as investigated by high-resolution transmission electron microscopy, consists in all cases of Pt single crystals with size about 3 nm embedded in an amorphous carbonaceous matrix. Due to the semiconducting character of the carbon matrix, which is the main component of the deposit, we propose that the transport results can be mapped onto those obtained in semiconducting materials with different degrees of doping. The different transport properties of Pt by FEBID and FIBID are attributed to the higher doping level in the case of FIBID, as given by composition measurements obtained with energy-dispersive X-ray microanalysis.

Ion Beam Study of Early Stages of Growth of GaN films on Sapphire

2002 ◽  
Vol 743 ◽  
Author(s):  
Eugen M. Trifan ◽  
David C. Ingram
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Ex Situ ◽  
Crystallographic Axis ◽  
In Situ Characterization ◽  
X Ray ◽  
Ion Channeling ◽  
Stages Of Growth ◽  
Early Stages

ABSTRACTAn innovative approach for in-situ characterization has been used in this work to investigate the composition, growth mode, morphology and crystalline ordering of the early stages of growth of GaN films grown on sapphire by MOCVD for substrate temperatures in the range of 450°C to 1050°C. We have performed in-situ characterization by Rutherford Backscattering Spectroscopy (RBS), Ion Channeling, X-ray Photoelectron Spectroscopy (XPS), and Low Energy Electron Diffraction. Ex-situ the films have been characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and thickness profilometry. The films have been grown in an in-house designed and build MOCVD reactor that is attached by UHV lines to the analysis facilities. RBS analysis indicated that the films have the correct stoichiometry, have variable thickness and for low substrate temperature completely cover the substrate while for temperatures 850°C and higher islands are formed that may cover as few as 5 percent of the substrate. From Ion Channeling and LEED we have determined the crystallographic phase to be wurtzite. The crystalline quality increases with higher deposition temperature and with thickness. The films are epitaxialy grown with the <0001> crystallographic axis and planes of the GaN films aligned with the sapphire within 0.2 degrees.

Amortization And Dynamic Recovery Of A2BO4 Structure Types During 1.5 MeV Krypton Ion-Beam Irradiation

1993 ◽  
Vol 321 ◽  
Author(s):  
L. M. Wang ◽  
W. L. Gong ◽  
R. C. Ewing
Keyword(s):  
Dynamic Recovery ◽  
Ion Beam ◽  
Recovery Process ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Materials Properties ◽  
Recovery Processes ◽  
Rate Of Increase ◽  
A Site

ABSTRACTThe temperature dependence of the critical amorphization dose, Dc, of four A2BO4 compositions, forsterite (Mg2SiO4), fayalite (Fe2SiO4), synthetic Mg2GeO4, and phenakite (Be2SiO4) was investigated by in situ TEM during 1.5 MeV Kr+ion beam irradiation at temperatures between 15 to 700 K. For the Mg- and Fe-compositions, the A-site is in octahedral coordination, and the structure is a derivative hep (Pbnm); for the Be-composition, the A- and B-sites are in tetrahedral coordination, forming corner-sharing hexagonal rings (R3). Although the Dc's were quite close at 15 K for all the four compositions (0.2–0.5 dpa), Dc increased with increasing irradiation temperature at different rates. The Dc-temperature curve is the result of competition between amorphization and dynamic recovery processes. The Dc rate of increase (highest to lowest) is: Be2SiO4, Mg2SiO4, Mg2GeO4, Fe2SiO4. At room temperature, Be2SiO4 amorphized at 1.55 dpa; Fe2SiO4, at only 0.22 dpa. Based on the Dc-temperature curves, the activation energy, Ea, of the dynamic recovery process and the critical temperature, Tc, above which complete amorphization does not occur are: 0.029, 0.047, 0.055 and 0.079 eV and 390, 550, 650 and 995 K for Be2SiO4, Mg2SiO4, Mg2GeO4 and Fe2SiO4, respectively. These results are explained in terms of the materials properties (e.g., bonding and thermodynamic stability) and cascade size which is a function of the density of the phases. Finally, we note the importance of increased amorphization cross-section, as a function of temperature (e.g., the low rate of increase of Dc with temperature for Fe2SiO4).

Defect Accumulation and Recovery in Ion-Implanted 6H-SiC

2002 ◽  
Vol 719 ◽  
Author(s):  
W. Jiang ◽  
W. J. Weber ◽  
C. M. Wangxya
Keyword(s):  
Single Crystal ◽  
Ion Beam ◽  
Irradiation Temperature ◽  
Recovery Processes ◽  
Defect Accumulation ◽  
Different Temperatures ◽  
Induced Defects ◽  
Ion Species ◽  
Irradiation Induced Defects

AbstractSingle crystal wafers of <0001>-oriented 6H-SiC were irradiated at different temperatures using a variety of ion species. The disorder on both the Si and C sublattices has been studied in situ using a combination of ion beam analyses in multiaxial channeling geometry. The fraction of the irradiation-induced defects surviving simultaneous recovery processes decreases with decreasing ion mass and with increasing irradiation temperature. Some of the Si and C defects are well aligned with the <0001> axis and the rate of C disordering is higher than that of Si disordering. Three recovery stages in Au2+-irradiated 6H-SiC have been identified.

Applications of In-situ Sample Preparation and Modeling of SEM-STEM Imaging

2008 ◽  
Author(s):  
R.J. Young ◽  
A. Buxbaum ◽  
B. Peterson ◽  
R. Schampers
Keyword(s):  
Sample Preparation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Dual Beam ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Preparation Techniques

Abstract Scanning transmission electron microscopy with scanning electron microscopes (SEM-STEM) has become increasing used in both SEM and dual-beam focused ion beam (FIB)-SEM systems. This paper describes modeling undertaken to simulate the contrast seen in such images. Such modeling provides the ability to help understand and optimize imaging conditions and also support improved sample preparation techniques.

scholarly journals Stability of Uranium Silicides During High Energy Ion Irradiation

1991 ◽  
Vol 235 ◽  
Author(s):  
R. C. Birtcher ◽  
L. M. Wang
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Amorphous State ◽  
Temperature Limit ◽  
High Energy ◽  
Grain Structure ◽  
Twin Structure ◽  
Fine Grain ◽  
Transmission Electron

ABSTRACTChanges induced by 1.5 MeV Kr ion irradiation of both U3Si and U3Si2 have been followed by in situ transmission electron microcopy. When irradiated at sufficiently low temperatures, both alloys transform from the crystalline to the amorphous state. When irradiated at temperatures above the temperature limit for ion-beam amorphization, both compounds disorder, with the Martensite twin structure in U3Si disappearing from view in TEM. Prolonged irradiation of the disordered crystalline phases results in nucleation of small crystallites within the initially large crystal grains. The new crystallites increase in number during continued irradiation until a fine grain structure is formed. Electron diffraction yields a powder-like diffraction pattern that indicates a random alignment of the small crystallites. During a second irradiation at lower temperatures, the small crystallizes retard amorphization. After 2 dpa at high temperatures, the amorphization dose is increased by over twenty times compared to that of initially unirradiated material.

In situ study of ion beam induced Si crystallization from a silicide interface

1993 ◽  
Vol 73 ◽  
pp. 264-267 ◽  
Author(s):  
F. Fortuna ◽  
M.-O. Ruault ◽  
H. Bernas ◽  
H. Gu ◽  
C. Colliex
Keyword(s):  
Ion Beam ◽  
In Situ Study
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