Electron-Phonon and Phonon-Phonon Interactions Under Laser Annealing Conditions

1984 ◽  
Vol 35 ◽  
Author(s):  
Alvin Compaan
Keyword(s):  
Laser Annealing ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Resonance Effects ◽  
Pulsed Laser Annealing ◽  
Annealing Conditions ◽  
Silent Phase ◽  
High Carrier ◽  
Anti Stokes ◽  
First Time

ABSTRACTSince the first time-resolved Raman studies of pulsed laser annealing (PLA) effects in Si, a number of cw Raman studies have been performed which provide a much improved basis for understanding the consequences on Raman spectra of temperature-dependent resonance effects, high carrier density effects, phonon anharmonicity, and strain effects. Here we briefly review these effects and then analyze the latest pulsed Raman studies of PLA including Stokes/anti-Stokes ratios, the shift and shape of the first order line, and time-resolved second-order spectra. The Raman data indicate the existence of a Raman-silent phase followed by a rapidly cooling solid which begins within 300 K of the normal melting temperature of Si. The Raman data also give evidence of carrier densities in the recrystallizing solid of ~1−2×l019/cm3 .

Pulsed–Raman Measurements of Temperature When Large Temperature Variations and Gradients are Present

1981 ◽  
Vol 4 ◽  
Author(s):  
R. F. Wood ◽  
M. Rasolt ◽  
G. E. Jellison
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Surface Region ◽  
Large Temperature ◽  
Temperature Dependent ◽  
Pulsed Laser Annealing ◽  
Highly Sensitive ◽  
Experimental Parameters ◽  
Anti Stokes ◽  
Straightforward Interpretation

ABSTRACTPulsed Raman temperature measurements by Lo and Compaan on Si samples have been interpreted as proving that the surface region does not melt during intense pulsed laser irradiation. In this paper, it is shown by detailed calculations with the melting model that the choice of experimental parameters in the Raman measurements can severely compromise a straightforward interpretation of the data. Moreover, it is demonstrated that temperatures extracted from Raman measurements are highly sensitive to the temperature-dependent optical properties of the material. Finally, it is pointed out that the very large temperature gradients present during pulsed laser annealing may entirely invalidate the Stokes/anti-Stokes ratio as an accurate temperature probe.

A Detailed Examination of Time-Resolved Pulsed Raman Temeperature Measurements of Laser Annealed Silicon

1983 ◽  
Vol 13 ◽  
Author(s):  
G. E. Jellison ◽  
D. H. Lowndes ◽  
R. F. Wood
Keyword(s):  
Optical Properties ◽  
Pulse Width ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Detailed Examination ◽  
Temperature Gradients ◽  
Probe Laser ◽  
Time Resolved ◽  
Pulsed Laser Annealing ◽  
Anti Stokes

ABSTRACTRaman temperature measurements during pulsed laser annealing of Si by Compaan and co-workers are critically examined. It has been shown previously that the Stokes to anti-Stokes ratio depends critically upon the optical properties of silicon as a function of temperature. These dependences, coupled with the large spatial and temporal temperature gradients normally found immediately after the high reflectivity phase, result in large variations in the calculated temperature depending upon the probe laser pulse width and the pulse-to-pulse and spatial variations in the annealing pulse energy density.

Calculations Pertaining to Raman Scattering During Laser Annealing of Ion-Implanted Silicon

1981 ◽  
Vol 4 ◽  
Author(s):  
R. F. Wood ◽  
D. H. Lowndes ◽  
G. E. Giles
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Rapid Onset ◽  
Simultaneous Occurrence ◽  
Raman Signal ◽  
Molten Silicon ◽  
Time Resolved ◽  
Pulsed Laser Annealing ◽  
Anti Stokes ◽  
Ion Implanted

ABSTRACTCompaan and co-workers have reported the results of time-resolved optical experiments on ion-implanted silicon which they claim prove the melting model of pulsed laser annealing cannot be correct. These results concern the rapid onset of a Raman signal after a heating laser pulse, the simultaneous occurrence of a Raman signal and the high reflectivity phase characteristic of molten silicon, and the lattice temperature measured by the Raman Stokes/anti-Stokes intensity ratio. In this paper, we show by detailed numerical calculations with the melting model that there is, in fact, excellent agreement between the results of the calculations and the experimental results reported by Compaan and co-workers.

Time-Resolved Raman Scattering and Transmission Measurements During Pulsed Laser Annealing

1980 ◽  
Vol 1 ◽  
Author(s):  
A. Compaan ◽  
H. W. LO ◽  
A. Aydinli ◽  
M. C. Lee
Keyword(s):  
Raman Scattering ◽  
Laser Annealing ◽  
Excitation Pulse ◽  
Dye Laser ◽  
Crystalline Lattice ◽  
Time Resolved ◽  
Pulsed Laser Annealing ◽  
Complete Recrystallization ◽  
Transmission Measurements ◽  
Anti Stokes

ABSTRACTRaman Scattering from a 7 nsec pulsed dye laser has been used to determine the onset of recrystallization following an 8 nsec dye laser excitation pulse in ion-implanted silicon. We find essentially complete recrystallization 59 nsec after the first excitation pulse and from Stokes-anti-Stokes ratios we find at 59 nsec a crystalline lattice temperature of 600 ± 200° C. Time-resolved transmission measurements at λ = 1.15 µm also demonstrate that no molten phase has occurred even though the usual reflectivity enhancement is observed.

Synchrotron X-Ray Study of the Structure of Silicon During Pulsed Laser Processing

1981 ◽  
Vol 4 ◽  
Author(s):  
B. C. Larson ◽  
C. W. White ◽  
T. S. Noggle ◽  
J. F. Barhorst ◽  
D. Mills
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Temperature Profiles ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Near Surface ◽  
X Ray ◽  
Pulsed Laser Annealing ◽  
Pulsed Laser Processing ◽  
Thermal Melting

ABSTRACTSynchrotron x-ray pulses have been used to make nanosecond resolution time-resolved x-ray diffraction measurements on silicon during pulsed laser annealing. Thermal expansion analysis of near-surface strains during annealing has provided depth dependent temperature profiles indicating >1100°C temperatures and diffraction from boron implanted silicon has shown evidence for near-surface melting. These results are in qualitative agreement with the thermal melting model of laser annealing.

Surface Temperatures and Dissociation Loss During the Pulsed Laser Annealing of GaAs

1983 ◽  
Vol 23 ◽  
Author(s):  
John T.A. Pollock ◽  
Alex Rose
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Pressure Data ◽  
Incident Laser ◽  
Time Resolved ◽  
Dissociation Pressure ◽  
Pulsed Laser Annealing ◽  
Modelling Studies ◽  
Maximum Temperatures ◽  
Good Agreement

ABSTRACTFrom reported equilibrium partial and total dissociation pressure data for GaAs and melt times derived from reported time resolved reflectivity experiments, estimates have been made of the anticipated rate of As loss. Good agreement was found with experimentally determined As loss. A similar approach using experimentally determined Ga loss data allowed estimates of the maximum temperatures reached during pulsed laser annealing. These temperatures are considerably higher than suggested in thermal modelling studies. The boiling point of Ga gould be exceeded at incident laser energies >0.8 J cm−2.

Time-resolved optical measurement of Si lattice temperature during nanosecond pulsed laser annealing

Physica B+C ◽  
1983 ◽  
Vol 117-118 ◽  
pp. 1024-1026 ◽  
Author(s):  
Kouichi Murakami ◽  
Hisayoshi Itoh ◽  
Kōki Takita ◽  
Kohzoh Masuda
Keyword(s):  
Laser Annealing ◽  
Optical Measurement ◽  
Pulsed Laser ◽  
Lattice Temperature ◽  
Time Resolved ◽  
Pulsed Laser Annealing ◽  
Nanosecond Pulsed Laser
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