Thermodynamic and Kinetic Studies of Pulsed-Laser Annealing from Transient Conductivity Measurements

1984 ◽  
Vol 35 ◽  
Author(s):  
P.S. Peercy ◽  
Michael O. Thompson
Keyword(s):  
Melting Temperature ◽  
Silicon Germanium ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Kinetic Studies ◽  
Alloy System ◽  
Velocity Versus ◽  
Solidification Velocity ◽  
Molten Layer ◽  
Amorphous Si

ABSTRACTSimultaneous measurements of the transient conductance and time-dependent surface reflectance of the melt and solidification dynamics produced by pulsed laser irradiation of Si are reviewed. These measurements demonstrate that the melting temperature of amorphous Si is reduced 200 ± 50 K from that of crystalline Si and that explosive crystallization in amorphous Si is mediated by a thin (≤ 20 nm) molten layer that propagates at ~ 15 m/sec. Studies with 3.5 nsec pulses permit an estimate of the dependence of the solidification velocity on undercooling. Measurements of the effect of As impurities on the solidification velocity demonstrate that high As concentrations decrease the melting temperature of Si (~ 150 K for 7 at.%), which can result in surface nucleation to produce buried melts. Finally, the silicon-germanium alloy system is shown to be an ideal model system for the study of superheating and undercooling. The Si50Ge50 alloy closely models amorphous Si, and measurements of layered Si-Ge alloy structures indicate superheating up to 120 K without nucleation of internal melts. The change in melt velocity with superheating yields a velocity versus superheating of 17 ± 3 k/m/sec.

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.

The Melting of Amorphous Si

1985 ◽  
Vol 57 ◽  
Author(s):  
J. M. Poate ◽  
P. S. Peercy ◽  
M. O. Thompson
Keyword(s):  
Melting Temperature ◽  
Pulsed Laser ◽  
Laser Melting ◽  
First Order ◽  
Explosive Crystallization ◽  
Liquid Transition ◽  
Melting Transitions ◽  
Amorphous Si

AbstractThe prediction by Turnbull and his colleagues that amorphous Si and Ge undergo first order melting transitions at temperatures Taℓ substantially beneath the crystalline melting temperature Tcℓ has stimulated much work. Structural, calorimet:ic and transient conductance measurements show that, for Si, Tcℓ – Taℓ lies in the range 225–250°K. Studies of the pulsed laser melting of the Si amorphous-liquid transition have resulted in the following findings, an estimate of the undercooling rate of 15°K/m/sec, an understanding of the mechanism mediating explosive crystallization, the formation of internal melts and segregation of dopants at the liquid-amorphous interface.

Multiple Layer Sputter Deposition and Laser Annealing of Silicon Films

1983 ◽  
Vol 23 ◽  
Author(s):  
W. W. Anderson ◽  
H. F. Mac Millan ◽  
J. S. Katzeff ◽  
M. Lopez
Keyword(s):  
Ion Implantation ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Sputter Deposition ◽  
Silicon Substrates ◽  
Chemical Cleaning ◽  
Pulsed Laser Annealing ◽  
Magnetron Sputter Deposition ◽  
Magnetron Sputter ◽  
Amorphous Si

ABSTRACTThe formation of single crystal multiple layers on silicon substrates with thicknesses in excess of 1 μm has been demonstrated to be a viable process. Film build-up is via repetitions of the steps (1) pre-deposition chemical cleaning of wafer, (2) magnetron sputter deposition of 0.3 pm thick amorphous Si, (3) interfacial mixing via 190 keV implantation of Si, and (4) film epitaxial crystallization via pulsed laser annealing. Doping has been demonstrated by both (1) P ion implantation and (2) P incorporation from PH3; included in the sputter gas ambient.

Effects of As impurities on the solidification velocity of Si during pulsed laser annealing

1985 ◽  
Vol 47 (3) ◽  
pp. 244-246 ◽  
Author(s):  
P. S. Peercy ◽  
Michael O. Thompson ◽  
J. Y. Tsao
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Solidification Velocity ◽  
Pulsed Laser Annealing

Pulsed laser annealing of rf sputtered amorphous Si‐H films doped with arsenic

1982 ◽  
Vol 53 (4) ◽  
pp. 3261-3266 ◽  
Author(s):  
E. Fogarassy ◽  
R. Stuck ◽  
M. Toulemonde ◽  
J. C. Bruyere ◽  
P. Siffert
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Pulsed Laser Annealing ◽  
Amorphous Si

Pulsed Laser Annealing of Silicon-Germanium Films

2002 ◽  
Vol 741 ◽  
Author(s):  
Sherif Sedky ◽  
Jeremy Schroeder ◽  
Timothy Sands ◽  
Roger Howe ◽  
Tsu-Jae King
Keyword(s):  
Surface Roughness ◽  
Silicon Germanium ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Chemical Vapor ◽  
Laser Pulses ◽  
Pulsed Laser Annealing ◽  
Pressure Chemical ◽  
Noticeable Reduction ◽  
Columnar Grain

ABSTRACTIn this work, we investigate the possibility of using pulsed laser annealing to locally tailor the physical properties of Si1-xGex (18% < × < 90%) prepared by low pressure chemical vapor deposition (LPCVD) at 400°C. Films which were amorphous as deposited showed, after laser annealing, strong {111} texture and a columnar grain microstructure and an average resistivity of 0.7 mΩ.cm. AFM showed that the first few laser pulses result in a noticeable reduction in surface roughness, which is proportional to the pulse energy. However, a large number of successive pulses dramatically increases the surface roughness.

Pulsed laser annealing of zinc implanted GaAs

1978 ◽  
Vol 14 (4) ◽  
pp. 85 ◽  
Author(s):  
S.S. Kular ◽  
B.J. Sealy ◽  
K.G. Stephens ◽  
D.R. Chick ◽  
Q.V. Davis ◽  
...  
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Pulsed Laser Annealing
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