Evidence for phase-explosion and generation of large particles during high power nanosecond laser ablation of silicon

Journal Article · Mon Feb 07 00:00:00 EST 2000 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.125894· OSTI ID:20215272

Yoo, J H ^[1]; Jeong, S H ^[1]; Mao, X L ^[1]; Greif, R ^[1]; Russo, R E ^[1]

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1. Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

The craters resulting from high-irradiance (1x10{sup 9}-1x10{sup 11} W/cm{sup 2}) single-pulse laser ablation of single-crystal silicon show a dramatic increase in volume at a threshold irradiance of 2.2x10{sup 10} W/CM{sup 2}. Time-resolved shadowgraph images show ejection of large particulates from the sample above this threshold irradiance, with a time delay {approx}300 ns. A numerical model was used to estimate the thickness of a superheated layer near the critical state. Considering the transformation of liquid metal into liquid dielectric near the critical state (i.e., induced transparency), the calculated thickness of the superheated layer at a delay time of 200-300 ns agreed with the measured crater depths. This agreement suggests that induced transparency promotes the formation of a deep superheated layer, and explosive boiling within this layer leads to particulate ejection from the sample. (c) 2000 American Institute of Physics.

• OSTI ID: 20215272
• Journal Information: Applied Physics Letters, Vol. 76, Issue 6; Other Information: PBD: 7 Feb 2000; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILICON
ABLATION
LASER RADIATION
PARTICULATES
RADIATION EFFECTS
CRATERS
EXPERIMENTAL DATA