TY - JOUR KW - Ablation KW - Laser KW - Laser ablation KW - Laser ablation KW - Spectroscopy KW - Phase KW - Explosion KW - Phase explosion KW - Phase-explosion KW - Inductively coupled plasma-mass spectroscopy AU - Jong-Hyun Yoo AU - Oleg V Borisov AU - Xianglei Mao AU - Richard E Russo AB -

A sudden increase in crater depth was observed during high irradiance (>1010 W/cm2) laser ablation of silicon, and it is attributed to the phenomenon of phase explosion. The threshold irradiance for phase explosion showed a dependence on two laser parameters:  laser beam spot size and wavelength. For a larger beam size and longer incident wavelength, a higher laser irradiance was required to generate phase explosion. The rapid increase of crater depth above the phase explosion threshold irradiance correlated with a significant increase in the ICPMS signal intensity. The ratio of crater volume to ICPMS intensity, which represents entrainment efficiency, remained the lowest at laser irradiances slightly above the phase explosion threshold. However, this ratio increased at irradiances well above the threshold (>1011 W/cm2). Chemical analysis using laser ablation at irradiance above 1011 W/cm2 provides increased sensitivity via improved entrainment and transport efficiency and increased ablation rate.

AN - 128 BT - Analytical Chemistry C2 - LBNL-47659 DA - 05/2001 DO - 10.1021/ac001333h IS - 10 LA - eng LB - Laser N1 -

LBNL-47659 IN FILE

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A sudden increase in crater depth was observed during high irradiance (>1010 W/cm2) laser ablation of silicon, and it is attributed to the phenomenon of phase explosion. The threshold irradiance for phase explosion showed a dependence on two laser parameters:  laser beam spot size and wavelength. For a larger beam size and longer incident wavelength, a higher laser irradiance was required to generate phase explosion. The rapid increase of crater depth above the phase explosion threshold irradiance correlated with a significant increase in the ICPMS signal intensity. The ratio of crater volume to ICPMS intensity, which represents entrainment efficiency, remained the lowest at laser irradiances slightly above the phase explosion threshold. However, this ratio increased at irradiances well above the threshold (>1011 W/cm2). Chemical analysis using laser ablation at irradiance above 1011 W/cm2 provides increased sensitivity via improved entrainment and transport efficiency and increased ablation rate.

PY - 2001 SP - 2288 EP - 2293 ST - Anal. Chem. T2 - Analytical Chemistry TI - Existence of phase explosion during laser ablation and its effects on inductively coupled plasma-mass spectroscopy VL - 73 ER -