Surface Structure and Morphology Modification of Silicon Layers Induced by Nanosecond Pulsed Laser Irradiation

1996 ◽  
Vol 441 ◽  
Author(s):  
A. Demchuk
Keyword(s):  
Surface Structure ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Silicon Substrates ◽  
Surface Phenomena ◽  
Time Resolved ◽  
Nanosecond Pulsed Laser ◽  
Morphology Modification ◽  
Nonmonotonic Behavior ◽  
Pulsed Laser Irradiation

AbstractThe results of laser induced surface structure modifications utilizing time-resolved reflectivity measurements are presented for the pulsed laser irradiation (λ. = 1.06 μm and 0.53 μm) of thin polysilicon (poly-Si) layers of 0.1 μm, 0.45 μm and 1.0 μm in thickness on silicon substrates. It was shown that when the poly-Si layer of 0.1-0.45 thickness is totally molten, during a solidification, a large-grained structure having grain sizes exceeding the thickness of the molten Si layer is formed. At the same time, the time-resolved reflectivity changes its value nonmonotonically. This nonmonotonic behavior is due to the outcropping of growing grains onto the surface before the formation of a solid crystalline front as well as to the influence of the surface phenomena on the crystallization process.

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.

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 Magnetic Properties on FeAl Stripes and Dots Induced by Nanosecond Pulsed Laser Irradiation

2014 ◽  
Vol 38 (4) ◽  
pp. 157-161 ◽  
Author(s):  
H. Kaiju ◽  
Y. Yoshida ◽  
S. Watanabe ◽  
K. Kondo ◽  
A. Ishibashi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Nanosecond Pulsed Laser ◽  
Pulsed Laser Irradiation

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.

Nanosecond pulsed laser irradiation of titanium: Oxide growth and effects on underlying metal

2014 ◽  
Vol 248 ◽  
pp. 38-45 ◽  
Author(s):  
D.P. Adams ◽  
R.D. Murphy ◽  
D.J. Saiz ◽  
D.A. Hirschfeld ◽  
M.A. Rodriguez ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Titanium Oxide ◽  
Pulsed Laser ◽  
Oxide Growth ◽  
Nanosecond Pulsed Laser ◽  
Pulsed Laser Irradiation
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