Study of 3-MeV electron irradiation damage in amorphous silicon with TRMC

2004 ◽  
Vol 808 ◽  
Author(s):  
A. Klaver ◽  
J.M. Warman ◽  
M.P. de Haas ◽  
J.W. Metselaar ◽  
R.A.C.M.M. van Swaaij
Keyword(s):  
Simple Model ◽  
Amorphous Silicon ◽  
Electron Irradiation ◽  
Probe Beam ◽  
Electron Accelerator ◽  
Defect Density ◽  
Irradiation Damage ◽  
Microwave Conductivity ◽  
Time Resolved

ABSTRACTThe effects of 3-MeV electron irradiation on a-Si:H have been studied using Time-Resolved Microwave Conductivity (TRMC). A Van der Graaff electron accelerator is used to generate the probe-beam pulses for the TRMC experiment as well as for the in-situ irradiation of the samples for the degradation of the material. Using several probe-beam pulse doses, TRMC transients were obtained on samples that have been subjected to various radiation fluences. These transients were later analyzed using a simple model based on the Shockley-Read-Hall capture and emission processes. Using these simulations we deduce a relationship between the radiation fluence and the defect density in the material.

Cathodoluminescence Microanalysis of Electron Irradiation Damage in Wide Band Gap Materials

1998 ◽  
Vol 540 ◽  
Author(s):  
M.A. stevens Kalceff ◽  
M.R. Phillips ◽  
M. Toth ◽  
A.R. Moon ◽  
D.N. Jamieson ◽  
...  
Keyword(s):  
Band Gap ◽  
Electron Irradiation ◽  
Depth Resolution ◽  
Wide Band ◽  
In Situ Monitoring ◽  
Irradiation Damage ◽  
Wide Band Gap ◽  
Energetic Radiation ◽  
Defect Species

AbstractCathodoluminescence (CL) microanalysis (spectroscopy and microscopy) in an electron microscope enables both pre-existing and irradiation induced local variations in the bulk and surface defect structure of wide band gap materials to be characterized with high spatial (lateral and depth) resolution and sensitivity. CL microanalytical techniques allow the in situ monitoring of electron irradiation induced damage, the post irradiation assessment of damage induced by other energetic radiation, and the investigation of irradiation induced electromigration of mobile charged defect species. Electron irradiated silicon dioxide polymorphs and MeV H+ ion implanted Type Ila diamond have been investigated using CL microanalytical techniques.

HREM In-Situ Studies of Electron Irradiation Effects in Oxides

1988 ◽  
Vol 100 ◽  
Author(s):  
D. E. Luzzi ◽  
L. D. Marks ◽  
M. I. Buckett ◽  
J. W. Strane ◽  
B. W. Wessels ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Point Of View ◽  
Irradiation Damage ◽  
Original Material ◽  
Irradiation Effects ◽  
Resolution Electron ◽  
Wide Range ◽  
Electronic Irradiation ◽  
High Resolution Electron Microscope

ABSTRACTHigh resolution electron microscope (HREM) studies provide the ability to study desorption and sputtering from the perspective of the analysis of the resultant materials, their structure, composition and atomic registry (orientation with respect to the original,material and the irradiation). This is a neglected facet of surface irradiation effects research, yet it is the most important from the technological point of view. In the current study, surface electron irradiation processes in oxides were studied in-situ in a Hitachi H-9000 HREM operated at incident electron energies of 100–300 keV. It was found that a wide range of processes occur in the HREM which are dependent on the energy and flux of the incident electrons and on the material properties. Both ballistic and electronic irradiation damage was observed and the material responses included surface sputtering, amorphisation, chemical disordering, desorption of O and metal surface layer creation, surface roughening and bulk defect creation.

PL and FTIR Absorption Study on Porous Silicon in Situ During Etching, in Oxygen Ambient, and After Chemical Oxidation

1992 ◽  
Vol 283 ◽  
Author(s):  
G. Mauckner ◽  
T. Walter ◽  
T. Baier ◽  
K. Thonke ◽  
R. Sauer Abteilung
Keyword(s):  
Defect Density ◽  
Chemical Oxidation ◽  
Laser Exposure ◽  
Porous Si ◽  
Radiative Recombination Rate ◽  
Time Resolved ◽  
Radiative Defect ◽  
Recombination Lifetimes ◽  
Time Resolved Photoluminescence

ABSTRACTSteady state and time-resolved photoluminescence (PL) and Fourier-transform infrared (FTIR) spectroscopy have been performed in situ during etching, on “as prepared” porous Si in air under laser exposure and on chemically oxidized porous Si. We suppose that PLdegradation of “as prepared” porous Si is caused by creating non-radiative defect centers during photooxidation. Chemically oxidized porous Si shows increased PL intensity and longer recombination lifetimes as compared to non-oxidized samples. We conclude, that an oxide layer with low defect density on the inner surface of chemically oxidized porous Si reduces the non-radiative recombination rate.

In-Situ crystallization of nano-wires and dots by electron irradiation in a field-emission TEM/STEM

1995 ◽  
Vol 53 ◽  
pp. 242-243
Author(s):  
M. Libera
Keyword(s):  
Field Emission ◽  
Electron Irradiation ◽  
Atomic Displacement ◽  
High Energy ◽  
Ex Situ ◽  
Time Resolved ◽  
First Results ◽  
Carbon Coated ◽  
Power Radiation

Specimen damage and heating by high-energy electron irradiation can be exploited to affect local specimen composition/temperature to drive phase transformations. Field-emission (FEG) sources are especially prone to inducing damage/heating, because their high brightness provides focused ~1nm FWHM/1.0nA probes. The physics of beam heating and damage are reviewed by Reimer (1,2). Heating is related to energy-loss mechanisms broadly summarized by the Bethe formula for stopping power. Radiation damage can cause atomic displacement, ionization, and bond scission. Displacement increases the point-defect concentration. Composition changes occur when displacements eject atoms from the specimen. This paper outlines first results using focused-probe irradiation in a Philips CM20 FEG TEM/STEM to locally crystallize an amorphous 80nm Ge48Te52 film. Ex-situ annealing leads to spherulitic crystallites. The crystallization kinetics have been studied by time-resolved reflectivity (3) and in-situ hot-stage optical microscopy (4). In-situ TEM annealing was done with a single-tilt hot stage. Films were floated from carbon-coated mica onto Cu grids. In-situ annealing under a parallel (low dose) beam leads to crystallization much like the ex-situ studies except that the crystallite morphology is highly anisotropic due to non-uniform film heating (5).

In situ characterization of microcrystalline silicon by time resolved microwave conductivity

1998 ◽  
Vol 227-230 ◽  
pp. 1001-1005 ◽  
Author(s):  
R Brenot ◽  
P Bulkin ◽  
P Roca i Cabarrocas ◽  
B Drévillon ◽  
R Vanderhaghen
Keyword(s):  
Microcrystalline Silicon ◽  
In Situ Characterization ◽  
Microwave Conductivity ◽  
Time Resolved

Relaxation of Electron Beam-Induced Metastable Defects in a-Si:II

1993 ◽  
Vol 297 ◽  
Author(s):  
M. Grimbergen ◽  
R. Mcconville ◽  
D. Redfield ◽  
R.H. Bube
Keyword(s):  
Activation Energy ◽  
Electron Beam ◽  
Amorphous Silicon ◽  
Time Constant ◽  
Electron Irradiation ◽  
Defect Density ◽  
Initial Density ◽  
Induced Defects ◽  
Metastable Defect

Relaxation of the metastable defect density in undoped amorphous silicon is observed after keV electron irradiation. The time constant for relaxation has an activation energy close to 1 eV, similar to that for light-induced defects. Relaxation appears to follow two or more stages. A large initial density relaxes rapidly, followed by slower relaxation more characteristic of light-induced defects. Separation of these components allows for a better comparison of e-beam and light-induced saturation defect density.

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