Early phase laser induced plasma diagnostics and mass removal during single-pulse laser ablation of silicon

Date Published
11/1999
Publication Type
Journal Article
Authors
DOI
10.1016/S0584-8547(99)00092-0
LBL Report Number
LBNL-43861
Abstract

The electron number density and temperature during the early phase (<300 ns) of laser-induced plasmas from silicon using a 266-nm, 3-ns Nd:YAG laser were deduced via spectroscopic methods. These parameters were measured as a function of delay time vs. irradiance in the range of 2–80 GW/cm2, and compared with crater volume measurements. A dramatic change in plasma characteristics (electron number density, temperature, and degree of ionization) as well as a sharp increase of mass removal was observed when the irradiance was increased beyond a threshold of 20 GW/cm2. Possible mechanisms such as inverse bremsstrahlung and self-regulation were used to describe these data in the low irradiance region. Laser self-focusing and critical temperature are discussed to explain the dramatic changes after the irradiance reaches the threshold.

Journal
Spectrochimica Acta Part B: Atomic Spectroscopy
Volume
54
Year of Publication
1999
Issue
11
Pagination
1607-1624
Keywords
Organizations
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