Sub-surface laser damage in sapphire and silicon: A path towards laser wafering

Som Nath Dahal, James A. Lebeau, Stuart Bowden, Christiana Honsberg

Research output: Chapter in Book/Report/Conference proceedingConference contribution


A variable wavelength nanosecond pulsed laser is used to create and characterize the subsurface damage in Sapphire and Silicon. The high intensity laser light of wavelengths that are transparent to crystalline Sapphire and silicon is used. The depth and size of the damage spots are compared with a ray-optics model and electron plasma breakdown model. The effect of focusing optics, number of shots, numerical aperture (NA) of the focusing optic on the experimentally measured subsurface damage spot size is presented. A range of spot sizes were formed from 100-300 μm in the bulk of sapphire without damaging the surface. Preferential chemical etchants and or cleaving methods will be implemented to peel thin wafers from the thicker ones. These results and the understanding in the fields of bulk material modification and internal laser micromachining of semiconductors will be implemented towards the laser wafering.

Original languageEnglish (US)
Title of host publication2016 IEEE 43rd Photovoltaic Specialists Conference, PVSC 2016
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages3
ISBN (Electronic)9781509027248
StatePublished - Nov 18 2016
Event43rd IEEE Photovoltaic Specialists Conference, PVSC 2016 - Portland, United States
Duration: Jun 5 2016Jun 10 2016


Other43rd IEEE Photovoltaic Specialists Conference, PVSC 2016
Country/TerritoryUnited States

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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