Laser Induced Breakdown Spectroscopy for Microanalysis of Surfaces

• Author / Creator

  Banerjee, Shyama P

• The utilization of Laser Induced Breakdown Spectroscopy (LIBS) as a potential
  material characterization technique has been demonstrated through academic
  and industrial research in past. LIBS has been applied for lateral surface
  scanning of materials and in depth resolution analysis. The necessity of improving
  lateral and depth resolution has led to the the development of microLIBS,
  a regime using low energy microjoule laser pulses. Femtosecond lasers have
  advanced the technique by its ability to produce high finer micromachined features.
  The optimization of pulse energy, optics, detectors and experimental
  environments are required to obtain precise surface microanalysis using LIBS.
  This thesis has been focused on a number of essential aspects of LIBS microanalysis.
  Laser ablation characteristics of materials depend on laser parameters
  and material properties. The single shot ablation threshold of chromium
  has been determined using UV femtosecond laser pulses and compared with
  two temperature model (TTM) predictions. The spatio-temporal evolution of
  the femtosecond laser induced micro-plasma plumes were characterized in the
  nanojoule ablation regime. The plume splitting, angular distribution of the
  plumes, plume lengths and plume images at threshold energies were characterized.
  Analytical models were used to compare plasma plume expansion and propagation characteristics. A LIBS depth profiling technique has been studied
  together with deep blind hole drilling using femtosecond laser pulses. The
  material removal rates were measured and compared with analytical calculations.
  The depth sensitive region that contributes to the LIBS emission has
  been evaluated for a single shot depth profiling study. It has been demonstrated
  by experiment and TTM model calculations that the depth sensitive
  region is much smaller than the ablated crater depth. Thin chromium lines
  on silicon wafers were prepared and scanning microanalysis across these metal
  strips using UV femtosecond pulses were carried out. Lateral resolution of the
  order of a micron has been obtained using LIBS.

• Subjects / Keywords

  • Laser Ablation
  • Laser Induced Breakdown Spectroscopy
  • Laser Micromachining
  • Two Temperature Model

• Graduation date

  Fall 2014

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3X09N

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.