Melting of Ion Implanted and Relaxed Amorphous Silicon

1989 ◽  
Vol 157 ◽  
Author(s):  
M.G. Grimaldi ◽  
P. Baeri ◽  
G. Baratta
Keyword(s):  
Amorphous Silicon ◽  
Threshold Energy ◽  
Pulsed Laser ◽  
Amorphous Layer ◽  
Surface Melting ◽  
Time Resolved ◽  
The Difference ◽  
Pulsed Laser Irradiation ◽  
Ion Implanted

ABSTRACTThe difference in the melting temperature of ion implanted and relaxed amorphous silicon has been measured. Pulsed laser irradiation (λ=347 nm, τ=30 ns) has been used to induce surface melting in the amorphous layer and time resolved reflectivity to detect the melting onset. The threshold energy density for surface melting in the relaxed amorphous was found 15.9±.3% higher than that in the unrelaxed one. The estimate of the variation of the thermal parameters in amorphous silicon upon relaxation allowed a determination of ΔTM=45±10 K between relaxed and unrelaxed amorphous silicon.

scholarly journals Overheating In Silicon During Pulsed-Laser Irradiation?

1985 ◽  
Vol 51 ◽  
Author(s):  
B. C. Larson ◽  
J. Z. Tischler ◽  
D. M. Mills
Keyword(s):  
Laser Irradiation ◽  
Thermal Strain ◽  
Pulsed Laser ◽  
Interface Velocity ◽  
High Energy ◽  
Time Resolved ◽  
Synchrotron Source ◽  
Zero Velocity ◽  
The Difference ◽  
Pulsed Laser Irradiation

ABSTRACTNanosecond resolution time-resolved x-ray diffraction measurements of thermal strain have been used to measure the interface temperatures in silicon during pulsed-laser irradiation. The pulsed-time-structure of the Cornell High Energy Synchrotron Source (CHESS) was used to measure the temperature of the liquid-solid interface of <111> silicon during melting with an interface velocity of 11 m/s, at a time of near zero velocity, and at a regrowth velocity of 6 m/s. The results of these measurements indicate 110 K difference between the temperature of the interface during melting and regrowth, and the measurement at zero velocity shows that most of the difference is associated with undercooling during the regrowth phase.

scholarly journals Qualification of Operational Amplifier used in Satellite Subsystem using Picosecond Pulsed Laser System

2020 ◽  
Vol 9 (2) ◽  
pp. 523-527
Keyword(s):  
Cross Section ◽  
Operational Amplifier ◽  
Second Harmonic ◽  
Laser System ◽  
Threshold Energy ◽  
Pulsed Laser ◽  
Spot Size ◽  
Single Event ◽  
532 Nm ◽  
Pulsed Laser Irradiation

Picosecond Pulsed Laser System (PPLS) was used to simulate the single event effects (SEE) on satellite electronic components. Single event transients effect induced in an operational amplifier (LM324) to determine how transient amplitude and charge collection varied with pulsed laser energies. The wavelength and the focused spot size are the primary factors generating the resultant charge density profile. The degradation performance of LM324 induced by pulsed laser irradiation with two wavelength (1064nm, 532nm) is determined as a function of laser cross section. The transient voltage changed due to pulsed laser hitting specific transistors. This research shows the sensitivity mapping of LM324 under the effect of fundamental and second harmonic wavelengths. Determine the threshold energy of the SET in both wavelength, and compare the laser cross section of 1064 nm beam and 532 nm beam.

Time-Resolved X-Ray Studies During Pulsed-Laser Irradiation of Ge

1984 ◽  
Vol 35 ◽  
Author(s):  
J.Z. Tischler ◽  
B.C. Larson ◽  
D.M. Mills
Keyword(s):  
Melting Point ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
High Energy ◽  
Measured Temperature ◽  
Time Resolved ◽  
Synchrotron Source ◽  
X Ray ◽  
Pulsed Laser Irradiation

ABSTRACTSynchrotron x-ray pulses from the Cornell High Energy Synchrotron Source (CHESS) have been used to carry out nanosecond resolution measurements of the temperature distrubutions in Ge during UV pulsed-laser irradiation. KrF (249 nm) laser pulses of 25 ns FWHM with an energy density of 0.6 J/cm2 were used. The temperatures were determined from x-ray Bragg profile measurements of thermal expansion induced strain on <111> oriented Ge. The data indicate the presence of a liquid-solid interface near the melting point, and large (1500-4500°C/pm) temperature gradients in the solid; these Ge results are analagous to previous ones for Si. The measured temperature distributions are compared with those obtained from heat flow calculations, and the overheating and undercooling of the interface relative to the equilibrium melting point are discussed.

Time-Resolved X-Ray Absorption of An Amorphous Si Foil During Pulsed Laser Irradiation

1985 ◽  
Vol 51 ◽  
Author(s):  
Kouichi Murakami ◽  
Hans C. Gerritsen ◽  
Hedser Van Brug ◽  
Fred Bijkerk ◽  
Frans W. Saris ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Direct Evidence ◽  
Pulsed Laser ◽  
Time Resolved ◽  
Edge Structure ◽  
X Ray ◽  
Nanosecond Pulsed Laser ◽  
Amorphous Si ◽  
X Ray Absorption ◽  
Pulsed Laser Irradiation

ABSTRACTWe report time-resolved X-ray absorption and extended X-ray absorption fine structure (EXAFS) measurements on amorphous silicon under nanosecond pulsed-laser irradiation. Each measurement was performed with one laser shot in the X-ray energy range from 90 to 300 eV. An X-ray absorption spectrum for induced liquid Si (liq*Si) was first observed above an energy density of 0.17 J/cm2. It differs significantly from the spectrum for amorphous Si and characteristically shows the disappearance of the Si-L(II,III) edge structure at around 100 eV. This phenomenon is interpreted in terms of a significant reduction in the 3s-like character of the unfilled part of the conduction band of liq*Si compared to that of amorphous Si. This is the first direct evidence that liq*Si has a metallic-like electronic structure. Timeresolved EXAFS results are also discussed briefly.

Time‐resolved temperature measurements during pulsed laser irradiation using thin film metal thermometers

1993 ◽  
Vol 64 (9) ◽  
pp. 2615-2623 ◽  
Author(s):  
D. P. Brunco ◽  
J. A. Kittl ◽  
C. E. Otis ◽  
P. M. Goodwin ◽  
Michael O. Thompson ◽  
...  
Keyword(s):  
Thin Film ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Temperature Measurements ◽  
Time Resolved ◽  
Pulsed Laser Irradiation

Melting Phenomena and Impurity Redistribution During Pulsed Laser Irradiation of Amorphous Silicon Layers

1983 ◽  
Vol 23 ◽  
Author(s):  
J. Narayan ◽  
C. W. White ◽  
O. W. Holland
Keyword(s):  
Electron Microscopy ◽  
Amorphous Silicon ◽  
Cross Section ◽  
Pulsed Laser ◽  
Nucleation And Growth ◽  
Bulk Nucleation ◽  
Section Electron ◽  
Section Electron Microscopy ◽  
Pulsed Laser Irradiation ◽  
Impurity Redistribution

ABSTRACTwe have investigated microstructural changes and phase transformations in 30Si+, 75As+, 63Cu+, and 115In+ implanted amorphous silicon layers as a function of pulse energy density. Cross-section electron microscopy studies have revealed the formation of two distinct regions, large and fine polycrystalline regions below the threshold for “defect-free” annealing. The fine polycrystalline region is formed primarily by explosive recrystallization, and occasionally by bulk nucleation and growth. The impurity redistribution in the large and fine polycrystalline regions were determined by Rutherford backscatterinq measurements. Large redistributions of impurities in the large poly region are consistent with velocity of solidifications of 3–5 ms−1. The nature of impurity redistributions in the fine poly region as a function of distribution coefficient provides information on the details of liquid phase crystallization phenomena.

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