Time-resolved reflectivity measurements of silicon and germanium pulsed excimer laser irradiation

Conference · Fri Nov 01 04:00:00 EST 1985

OSTI ID:6447211

Jellison, Jr, G E; Lowndes, D H; Mashburn, D N; Wood, R F

Time-resolved reflectivity measurements of silicon and germanium have been made during pulsed KrF excimer laser irradiation. The reflectivity was measured simultaneously at both 1152 and 632.8 nm wavelengths, and the energy density of each laser pulse was monitored. The melt duration and the time of the onset of melting were measured and compared with the results of melting model calculations. For energy densities just above the melting threshold, it was found that the melt duration was never less than 20 ns for Si and 25 ns for Ge, while the maximum reflectivity increased from the value of the hot solid to that of the liquid over a finite energy range. These results, along with a reinterpretation of earlier time-resolved ellipsometry measurements, indicates that, during the melt-in process, the near-surface region does not melt homogeneously, but rather consists of a mixture of solid and liquid phases. The reflectivity at the onset of melting and in the liquid phase have been measured at both 632.8 and 1152 nm, and are compared with the results found in the literature.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6447211
• Report Number(s): CONF-851217-22; ON: DE86004804
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
ELEMENTS
FLUORIDES
FLUORINE COMPOUNDS
GERMANIUM
HALIDES
HALOGEN COMPOUNDS
HEATING
IRRADIATION
KRYPTON COMPOUNDS
KRYPTON FLUORIDES
LASER-RADIATION HEATING
MELTING
METALS
OPTICAL PROPERTIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PLASMA HEATING
PULSED IRRADIATION
RARE GAS COMPOUNDS
REFLECTIVITY
SEMIMETALS
SILICON
SURFACE PROPERTIES