Kinetic and thermodynamic studies of pulsed laser irradiation

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5727315

Peercy, P S; Thompson, M O

Simultaneous measurements of the transient conductance, to determine the molten layer thickness versus time, and the time-dependent surface reflectance, to determine the melt duration at the surface during pulsed laser irradiation, are reviewed. These real-time measurements have been applied in a variety of studies of Si and Si-based alloys. In crystalline Si, melt initiates at the surface and propagates to some depth, whereupon the motion of the liquid/solid interface reverses and the material solidifies. In amorphous Si, these measurements were used to determine the melting temperature of the amorphous phase and the mechanism by which explosive crystallization occurs. In Si implanted with impurities, combined transient conductance and reflectance measurements reveal the occurrence of such novel melt and solidification scenarios as internal nucleation of melt and surface nucleation of solid on molten Si. Internal melts, which were previously unexpected, appear to be quite common and explain unusual microstructures observed by TEM.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA); Cornell Univ., Ithaca, NY (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5727315
• Report Number(s): SAND-85-2830C; CONF-860620-8; ON: DE86012175
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
AMORPHOUS STATE
ARSENIC
ELEMENTS
HEATING
IMPURITIES
INDIUM
IRRADIATION
LASER-RADIATION HEATING
LAYERS
MELTING
METALS
OPTICAL PROPERTIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PLASMA HEATING
PULSED IRRADIATION
REFLECTIVITY
SEMIMETALS
SILICON
SURFACE PROPERTIES