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*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


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
Early online date25 Sep 2018
Publication statusPublished - 31 Dec 2018
Externally publishedYes


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