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 publication2017 IEEE 44th Photovoltaic Specialist Conference, PVSC 2017
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages3
ISBN (Electronic)9781509056057
StatePublished - May 25 2018
Event44th IEEE Photovoltaic Specialist Conference, PVSC 2017 - Washington, United States
Duration: Jun 25 2017Jun 30 2017


Other44th IEEE Photovoltaic Specialist Conference, PVSC 2017
CountryUnited States

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

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