Ablation threshold measurements and surface modifications of 193 nm laser irradiated 4H-SiC

A. F. Mohammed, Q. A. Al-Jarwany, A. J. Clarke, T. M. Amaral, J. Lawrence, N. T. Kemp, C. D. Walton

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

We report laser ablation experiments on polished 4H-SiC wafers using an 193 nm ArF laser over a fluence range of mJ cm−2–5000 mJ cm−2. An onset of material modification was measured at a laser fluence of 925 ± 80 mJ cm−2, and a concomitant etch rate of ∼200 pm per pulse. Laser ablation sites have been analysed using optical microscopy, scanning electron microscopy, Raman microscopy and white light interferometry. Finite element simulations using COMSOL™ Metaphysics, 5.3 have been used to calculate laser induced temperature rise of 4H-SiC as a function of laser fluence. The laser fluence required to reach the melting points of silicon, silicon carbide and carbon have been calculated and correspond to ∼970, 1950, 2600 mJ cm−2 respectively. Two different surface modifications are observed. At a laser fluence in the region of 1.0 J cm−2 the irradiated site removed material forming a uniform crater. At a higher laser fluence, in the region of 2700 mJ cm−2, nodule-like structures form on the base of the ablation crater. The dissociation of laser irradiated 4H-SiC is briefly discussed.

Original languageEnglish
Pages (from-to)194-202
Number of pages9
JournalChemical Physics Letters
Volume713
Early online date25 Sep 2018
DOIs
Publication statusPublished - 1 Dec 2018

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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