Micro three-dimensional removal processing inside sapphire substrate

Kensuke Tokumi, Shigeki Matsuo, Satoshi Kiyama, Takuro Tomita, Shuichi Hashimoto

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Femtosecond laser-assisted etching is a promising technique as micro three-dimensional removal processing. This technique consists of two-steps: the first step is irradiation of focused femtosecond (fs) laser pulses along the pre-designed pattern, and next step is wet etching. Provided the modified region is etched faster than the un-modified host material, the modified region is selectively removed. However, when this technique was applied to volume etching of sapphire, there was a problem of incomplete removal (residues remain after etching). In the present report, we propose and demonstrate a new strategy of two-cycle process, i.e., repeating {irradiation-etching} cycle two-times. The region that should be removed was divided into two. Outer layer was etched at the first cycle and inner volume was etched at the second cycle. In this way, the etching capability was improved as well as suppressing undesirable side effects of cracks and surface pits.

Original languageEnglish
Pages (from-to)179-182
Number of pages4
JournalJournal of Laser Micro Nanoengineering
Issue number2
Publication statusPublished - 2010 Jun
Externally publishedYes


  • Femtosecond laser processing
  • Femtosecond laser-assisted etching
  • Sapphire
  • Two-cycle process

ASJC Scopus subject areas

  • Instrumentation
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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