Pulsed Laser Annealing of Aluminum

1980 ◽  
Vol 1 ◽  
Author(s):  
W. R. Wampler ◽  
D. M. Follstaedt ◽  
P. S. Peercy
Keyword(s):  
Single Crystal ◽  
Laser Irradiation ◽  
Reasonable Agreement ◽  
Ruby Laser ◽  
Laser Annealing ◽  
Ion Beam ◽  
Pulsed Laser ◽  
Nucleation Time ◽  
Pulsed Laser Annealing ◽  
Beam Analysis

ABSTRACTPulsed ruby laser irradiation of unimplanted single crystal and implanted polycrystalline Al has been studied with ion beam analysis and TEM. The results show that Al is melted to a depth of ∼ 0.9 μm with a 4.2 J/cm2 , 15 nsec pulse, and that vacancies are quenched into Al during resolidification. Diffusion of Zn in liquid Al is observed, and a melt time of ∼ 65 nsec is estimated for a 3.8 J/cm2, 30 nsec pulse. The observations are in reasonable agreement with calculations of sample temperature and melt times. We observe no precipitation of AlSb in liquid Al for Sbimplanted Al, and conclude that the nucleation time satisfies 50 nsec ≲ tnuc ≲ 200 nsec. We find no evidence for amorphous Al after irradiation of single crystal Al with energies ≳ 1.5 J/cm2.

Raman Vibrational Study of Pulsed Laser Annealing of Implanted GaAs

1983 ◽  
Vol 23 ◽  
Author(s):  
J. Sapriel ◽  
Y.I. Nissim
Keyword(s):  
Laser Irradiation ◽  
Raman Spectra ◽  
Ruby Laser ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Spatially Resolved ◽  
Pulsed Laser Annealing ◽  
Vibrational Study ◽  
Annealing Cycle ◽  
Pulsed Laser Irradiation

ABSTRACTThe lattice reconstruction produced by a pulsed laser irradiation in heavily damaged GaAs layers is studied. Spatially resolved Raman measurements are used to characterize the crystalline quality after the annealing cycle produced by a O-switched Ruby laser or by a picosecond pulsed Nd-YAG laser. The continuous evolution in the Raman spectra is usèd to follow the crystal recovery as a function of the irradiation parameters.

Pulsed Laser Annealing of R.F.Sputtered Amorphous Si : H.Films, Doped with Arsenic

1981 ◽  
Vol 4 ◽  
Author(s):  
E. Fogarassy ◽  
R. Stuck ◽  
M. Toulemonde ◽  
P. Siffert ◽  
J.F. Morhange ◽  
...  
Keyword(s):  
Ruby Laser ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Amorphous Layer ◽  
High Concentration ◽  
Topographic Analysis ◽  
Pulsed Laser Annealing ◽  
Residual Hydrogen ◽  
Silicon Target ◽  
Amorphous Si

Arsenic doped amorphous silicon layers have been deposited on silicon single crystals by R.F.cathodic sputtering of a silicon target in a reactive argon-hydrogen mixture, and annealed with a Q-switched Ruby laser. Topographic analysis of the irradiated layers has shown the formation of a crater, due to an evaporation effect of material which could be related to the presence of a high concentration of Ar in the amorphous layer. RBS and Raman Spectroscopy showed that the remaining layer is not recrystallised probably due to inhibition by the residual hydrogen. However, it was found that arsenic diffuses into the monocrystalline substrate by laser induced diffusion of dopant from the surface solid source, leading to the formation of good quality P-N junctions.

Transient Conductance Measurements During Pulsed Laser Annealing

1981 ◽  
Vol 4 ◽  
Author(s):  
M. O. Thompson ◽  
G. J. Galvin ◽  
J. W. Mayer ◽  
R. B. Hammond ◽  
N. Paulter ◽  
...  
Keyword(s):  
Single Crystal ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Interface Velocity ◽  
Laser Pulses ◽  
Molten Layer ◽  
Pulsed Laser Annealing ◽  
Complete Melting ◽  
Solid Liquid Interface ◽  
Solid Liquid

ABSTRACTMeasurements were made of the conductance of single crystal Au-doped Si and silicon-on-sapphire (SOS) during irradiation with 30 nsec ruby laser pulses. After the decay of the photoconductive response, the sample conductance is determined primarily by the thickness and conductivity of the molten layer. For the single crystal Au-doped Si, the solid-liquid interface velocity during recrystallization was determined from the current transient to be 2.5 m/sec for energy densities between 1.9 and 2.6 J/cm2, in close agreement with numerical simulations based on a thermal model of heat flow. SOS samples showed a strongly reduced photoconductive response, allowing the melt front to be observed also. For complete melting of a 0.4 μm Si layer, the regrowth velocity was 2.4 m/sec.

Oxidation Effects During the Formation of Buried Sb Dopant Profiles in Silicon Using Pulsed Laser Epitaxy

1991 ◽  
Vol 235 ◽  
Author(s):  
Randall J. Carolissen ◽  
R. Pretorius
Keyword(s):  
Single Crystal ◽  
Laser Irradiation ◽  
Oxidation Kinetics ◽  
Ruby Laser ◽  
Pulsed Laser ◽  
Single Crystal Silicon ◽  
Heating Time ◽  
No Oxidation ◽  
Crystal Silicon ◽  
Oxygen Concentrations

ABSTRACTSevere oxidation inhibited epitaxy when buried Sb profiles in single crystal silicon were formed from evaporated layers irradiated in atmosphere with a pulsed Q-switched ruby laser. Oxygen concentrations as high as 5×1017atoms/cm2 (equivalent to 105nm SiO2) were measured. However, structures prepared without the Sb layer and irradiated under identical conditions, showed no oxidation. Oxidation of Sb as a source of the measured oxygen was ruled out, while the total heating time during laser irradiation is so short (nano- to milliseconds) that normal oxidation kinetics cannot account for the amount of SiO2 measured. Irradiations in vacuum and in a helium ambient showed that the oxygen responsible for these effects is supplied from the ambient in which irradiations are carried out. Also no oxidation was observed when structures, prepared on a substrate heated to 350°C, were irradiated in atmosphere. A model to account for these oxidation effects is proposed.

Impurity Activation in N+ Ion-Implanted 6H-SiC with Pulsed Laser Annealing Method

2000 ◽  
Vol 640 ◽  
Author(s):  
O. Eryu ◽  
K. Aoyama ◽  
K. Abe ◽  
K. Nakashima
Keyword(s):  
Contact Resistance ◽  
Laser Irradiation ◽  
Carrier Density ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Surface Region ◽  
Near Surface ◽  
Pulsed Laser Annealing ◽  
Annealing Method ◽  
Ion Implanted

ABSTRACTWe have succeeded in pulsed laser annealing of N+ ion-implanted n-type 6H-SiC for increasing the carrier density near surface in order to decrease contact resistance, which induces little redistribution of implanted impurities after laser irradiation. By repeated laser irradiation at low energy density, the ion–implanted impurities were electrically activated without melting the surface region. SiC substrates with impurity concentration of 2×1018 /cm3 were implanted with 30 keV N+ ions with dose of 4.7×1013/cm2. After pulsed laser annealing, a contact resistance was measured to be 5.7×10−5 Ωcm2 using Al electrode on the N+ -implanted layer.

Pulsed Laser Annealing of Zirconia Capped, Native Oxides Free GaAs Surfaces

1983 ◽  
Vol 23 ◽  
Author(s):  
D. Pribat ◽  
L.M. Mercandalli ◽  
M. Croset ◽  
J. Siejka
Keyword(s):  
Laser Irradiation ◽  
Laser Annealing ◽  
Defect Density ◽  
Pulsed Laser ◽  
Native Oxide ◽  
Thermally Activated ◽  
Native Oxides ◽  
Pulsed Laser Annealing ◽  
Gaas Substrates ◽  
Pulsed Laser Irradiation

ABSTRACTWe have studied the effects of pulsed laser irradiation on silicon implanted, thermally activated , Calcia Stabilized Zirconia (CSZ) capped GaAs substrates. Reference substrates have also been irradiated in air for comparison. CSZ as a solid electrolyte has been used to chemically reduce the GaAs surface native oxides prior to irradiation while maintaining the surface stoechiometry. Our results indicate a spectacular decrease in defect density after laser irradiation of the CSZ capped-native oxide free samples, as compared to the samples irradiated in air.

Amorphous Phase Trapping as a Result of Pulsed Laser Irradiation of Silicon

1983 ◽  
Vol 13 ◽  
Author(s):  
R. F. Wood
Keyword(s):  
Phase Transition ◽  
Laser Irradiation ◽  
Amorphous Phase ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Rate Model ◽  
Kinetic Rate ◽  
Pulsed Laser Annealing ◽  
Thermodynamic Effect ◽  
Pulsed Laser Irradiation

ABSTRACTIt is concluded that large interface undercoolings of ˜ 300 deg are not likely to occur during pulsed laser annealing and that the observed liquid to amorphous phase transition is not a purely thermodynamic effect. It is then shown that the formation of the amorphous phase can be understood on the basis of a kinetic rate model which makes large undercoolings of the interface unnecessary.

Stress Effects on Raman Measurements of Pulsed Laser Annealed Silicon

1983 ◽  
Vol 23 ◽  
Author(s):  
G. E. Jellison ◽  
R. F. Wood
Keyword(s):  
Raman Scattering ◽  
Laser Irradiation ◽  
Laser Annealing ◽  
Phonon Frequency ◽  
Pulsed Laser ◽  
Front Surface ◽  
Surface Region ◽  
Pulsed Laser Annealing ◽  
Anti Stokes ◽  
Pulsed Laser Irradiation

ABSTRACTIt has recently been shown that the front surface region of the silicon lattice is severely strained during pulsed laser irradiation. This uniaxial strain reduces the symmetry of the front surface region, resulting in additional shifts and splittings of the phonon frequency and changes in the Raman scattering tensor. It is shown that, for the case of pulsed laser irradiation, the phonon frequency is increased, and the 3-fold degenerate optical phonon is split into a singlet and a doublet. The changes in the Raman scattering tensor make it non-symmetric, and generally invalidate the technique used by Compaan et al. to determine the cross section experimentally. The complications introduced by the presence of stress during pulsed laser annealing, coupled with the temperature dependence of the optical and Raman tensors, make a simple interpretation of the Stokes to anti-Stokes ratio in terms of lattice temperature extremely unreliable.

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