7 September 1994 Diagnostics of nanosecond laser-induced phase transitions in silicon
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Proceedings Volume 2207, Laser Materials Processing: Industrial and Microelectronics Applications; (1994) https://doi.org/10.1117/12.184782
Event: Europto High Power Lasers and Laser Applications V, 1994, Vienna, Austria
Solid-liquid phase transitions initiated by nanosecond heating of Si surface with monopulse radiation of a ruby laser have been studied. Changes in the aggregative state of Si were diagnosed by optical probing of irradiated zone at 0.53 or 1.06 micrometers and by means of thermal radiation pyrometry at the effective wavelength of 525 nm. Dynamics of the probing radiation reflection and scattering were studied by directing the probe beam at the central region of the irradiated zone both directly and from the backside through the specimen volume. Numerical modelling has been conducted of the phase transitions and optical absorption at (lambda) equals 1.06 micrometers under the internal reflection of probing radiation from moving liquid-solid interface. It has been shown that the surface temperature of the melt is nearly constant at the epitaxial crystallization stage. At the onset of melting and at the end of solidification stage, the Si surface is optically nonuniform due to coexistence of crystal and liquid microscale areas. The typical size of heterogeneous surface irregularity has been estimated. Local fluctuations at the moving liquid-solid interface result in irregularity of the liquid-solid interface that causes scattering of the probe radiation. Possibility has been demonstrated of using optical diagnostics of phase transitions occurring under laser irradiation of a semiconductor immersed in translucent liquid (water), where traditional optical probing is not effective.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Gennadii D. Ivlev, Elena I. Gatskevich, "Diagnostics of nanosecond laser-induced phase transitions in silicon", Proc. SPIE 2207, Laser Materials Processing: Industrial and Microelectronics Applications, (7 September 1994); doi: 10.1117/12.184782; https://doi.org/10.1117/12.184782


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