Raman Studies of Carrier Activation in Laser Annealed GaAs Capped with Silicon Nitride

1986 ◽  
Vol 74 ◽  
Author(s):  
A. Compaan ◽  
S. C. Abbi ◽  
H. D. Yao ◽  
A. Bhat ◽  
F. Hashmi
Keyword(s):  
Silicon Nitride ◽  
Laser Pulse ◽  
Raman Scattering ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Dye Laser ◽  
Pulsed Laser Annealing ◽  
Wide Range ◽  
Xecl Excimer Laser

AbstractCarrier concentrations exceeding 1019/cm3 in GaAs implanted with Si (2 × 1014/cm2 @ 140 keV) have been obtained by pulsed laser annealing with either a dye laser (λ = 728 nm) or a XeCl excimer laser (λ = 308 nm). Carrier concentrations were measured by plasmon Raman scattering over a wide range of anneal energy densities. Compared with capless laser annealing, much higher carrier activations were achieved when the annealing laser pulse was incident through a Si3N4 cap.

Pulsed Excimer Laser Processing of AlN/GaN Thin Films

1996 ◽  
Vol 449 ◽  
Author(s):  
W. S. Wong ◽  
L. F. Schloss ◽  
G.S. Sudhir ◽  
B. P. Linder ◽  
K-M. Yu ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Density ◽  
Excimer Laser ◽  
Laser Processing ◽  
Laser Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Pulsed Laser ◽  
Emission Peak ◽  
Dopant Activation ◽  
Pulsed Laser Annealing

ABSTRACTA KrF (248 nm) excimer laser with a 38 ns pulse width was used to study pulsed laser annealing of AIN/GaN bi-layers and dopant activation of Mg-implanted GaN thin films. For the AIN/GaN bi-layers, cathodoluminescence (CL) showed an increase in the intensity of the GaN band-edge peak at 3.47 eV after pulsed laser annealing at an energy density of 2000 mJ/cm2. Rutherford backscattering spectrometry of a Mg-implanted A1N (75 nm thick)/GaN (1.0 μm thick) thin-film heterostructure showed a 20% reduction of the 4He+ backscattering yield after laser annealing at an energy density of 400 mJ/cm2. CL measurements revealed a 410 nm emission peak indicating the incorporation of Mg after laser processing.

Raman and Optical Properties of the Pulsed Laser Annealing Phase of SI

1981 ◽  
Vol 4 ◽  
Author(s):  
A. Compaan ◽  
A. Aydinli ◽  
M. C. Lee ◽  
H. W. LO
Keyword(s):  
Optical Properties ◽  
Laser Pulse ◽  
Absorption Coefficient ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Experimental Tests ◽  
Small Temperature ◽  
Pulsed Laser Annealing ◽  
Near Ir ◽  
Transmission Measurements

ABSTRACTRaman measurements of temperature reported earlier have been repeated using a doubled Nd: YAG pulse for excitation and an electronically delayed dye laser pulse. These results, together with a variety of experimental tests of the Raman method, confirm the validity of the small temperature rise during pulsed laser annealing. Transmission measurements spanning the visible and near IR show that there exists a thin (∼ 70 nm) layer at the surface in which the induced absorption coefficient is ∼ 7 × 105 cm−1.

Melting and Laser Annealing in Semiconductors using 0.485 μm and 0.193 μm Pulsed Lasers

1980 ◽  
Vol 2 ◽  
Author(s):  
J. Narayan ◽  
J. Fletcher ◽  
R. E. Eby
Keyword(s):  
Laser Irradiation ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Convincing Evidence ◽  
Dye Laser ◽  
Pulsed Lasers ◽  
Displacement Damage ◽  
Melting Phenomenon ◽  
Pulsed Laser Irradiation

ABSTRACTAnnealing of displacement damage, the dissolution of boron precipitates, the formation of constitution supercooling cells, and the broadening of dopant profiles have been studied in laser annealed silicon. These samples were irradiated with a dye laser (λ = 0.485 µm, τ = 9 ns, E = 0.7–1.2 J cm−2) and an Excimer laser (λ = 0.193 µm, τ= 9 ns, E = 0.5–0.7 J cm−2) pulses. These results can be consistently interpreted by invoking melting during pulsed laser irradiation. Thus these results provide convincing evidence for the melting phenomenon.

Electrical Properties of β -FeSi2/Si Hetero-Diode Improved by Pulsed Laser Annealing

2003 ◽  
Vol 799 ◽  
Author(s):  
Keiichi Tsuchiya ◽  
Noboru Miura ◽  
Hironaga Matsumoto ◽  
Ryotaro Nakano ◽  
Shin-ichiro Uekusa
Keyword(s):  
Electrical Properties ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Excimer Laser Annealing ◽  
Iron Disilicide ◽  
Β Phase ◽  
Pulsed Laser Annealing ◽  
Phase Crystal ◽  
Graded Junction

ABSTRACTβ-phase iron disilicide (β-FeSi2) was obtained on n-type silicon (111) substrate by using excimer laser annealing (ELA). β-phase crystal which have good electrical properties was grown within a narrow annealing condition such as energy density. All samples were annealed by excimer laser show n-type characteristic. Graded junction was formed in FeSi2/Si hetero diode.

A Laser Triggered Self-Sustaining Metals-Compound Semiconductor Transition for AlSb

1981 ◽  
Vol 4 ◽  
Author(s):  
R. Andrew ◽  
L. Baufay ◽  
A. Pigeolet ◽  
L.D. Laude
Keyword(s):  
Laser Pulse ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Pulsed Laser Annealing ◽  
Short Laser Pulses ◽  
Thermally Triggered ◽  
Heat Of Transformation ◽  
Complete Transformation

ABSTRACTThe preparation of AlSb thin films by pulsed laser annealing of Al/Sb sandwiches is studied in order to resolve some past controversy about the temperature rise induced by the laser pulse. Using 1000 Ȧ thick two layer films supported by TEM grids, we investigate the energy threshold for complete transformation as a function of pulse duration from 15 nsec to 100 msec, and of ambient temperature from −100°C to 250°C.We thence calculate the temperature effect directly induced by the laser to be about 930°C, or approximately the melting point of the metals, whereas inert gas furnace anneals of comparable films show transformation at this temperature occuring only in about 100 sec. We discuss the isoenergetic nature of the system for short laser pulses and the role of the heat of transformation, and thus conclude that the reaction is thermally triggered by the laser pulse but is to some extent self-sustaining via the heat of transformation locally distributed. This model is also shown to have equal validity for the systems CdTe, CdSe and AlAs.

First and Second Order Raman Studies of Composition and Structural Ordering in Hg1−xCdxTe

1989 ◽  
Vol 161 ◽  
Author(s):  
A. Compaan ◽  
R. C. Bowman
Keyword(s):  
Laser Annealing ◽  
Cluster Formation ◽  
Pulsed Laser ◽  
Second Order ◽  
Bulk Growth ◽  
Resonance Behavior ◽  
Pulsed Laser Annealing ◽  
Wide Range ◽  
Laser Anneal ◽  
Defect Densities

ABSTRACTThe effects of alloy fluctuations, defect densities, and short-range clustering on the resonance behavior of first and second order LO and TO Raman scattering are studied in Hg1−xCdxTe (MCT). X-values between 0.20 and 0.32 and photon energies from 2.35 to 2.7 eV were used with samples prepared by a wide range of techniques--LPE, MOCVD, MBE, bulk growth, and pulsed laser annealing. We examine the resonance behavior of the HgTe-like TO mode at ∼120 cm−1 and the mode at 133 cm−1, which has been identified as originating from the preferential clustering of 3 Hg and 1 Cd about the Te. We find that the intensity of this peak for various bulk and epitaxially grown samples is unusually large only near the E, resonance. Pulsed laser annealing with a Nd:YAG-pumped dye laser strongly suppresses this mode in all samples suggesting that extremely rapid epitaxial regrowth may inhibit the 3:1 cluster formation. In addition, the resonance-enhanced LO overtones are suppressed by the pulsed laser anneal.

Faster Quenching by Silicon Pulsed Laser Annealing Under Water

1986 ◽  
Vol 74 ◽  
Author(s):  
A. Polman ◽  
S. Roorda ◽  
S. B. Ogale ◽  
F. W. Saris
Keyword(s):  
Laser Pulse ◽  
Laser Annealing ◽  
Crystalline Silicon ◽  
Diffusion Theory ◽  
Pulsed Laser ◽  
Silicon Layer ◽  
Water Layer ◽  
Amorphous Layer ◽  
Pulsed Laser Annealing ◽  
Novel Method

AbstractA novel method of pulsed laser processing of ion-implanted silicon is presented, in which samples are irradiated in water ambient. The water layer in contact with the silicon during irradiationh as a considerable influence on melting and solidificationd ynamics. Still, perfect epitaxy of a thin amorphous layer can be obtained using this method.For epitaxy to occur on a sample irradiated under water, 40 % more absorbed energy is necessary than for a sample irradiated in air. This indicates the occurrence of a considerable heat-flow from the silicon into the water layer during the laser pulse. From impurity redistribution after irradiation it is found that by processing a sample under water liquid-phase diffusion is reduced. Diffusion theory arguments indicate that this can be due to a reduction in total melt duration by about afactor 2–3. This can be due to faster cooling of the liquid silicon layer after the laser pulse whereas the melt-in time might be influenced as well. As a consequence, shallower impurity profiles can be obtained in crystalline silicon. No oxygen incorporation is detected and the surface morphology is not disturbed using this new process.

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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