SEM, AFM and TEM studies for repeated irradiation effect of femtosecond laser on 4H-SiC surface morphology at near threshold fluence

Chengwu Wang, Syuhei Kurokawa, Toshiro Doi, Julong Yuan, Li Fan, Masatoshi Mitsuhara, Huizong Lu, Weifeng Yao, Yu Zhang, Kehua Zhang

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

In order to investigate the interaction of femtosecond (fs) laser and hard-to-process semiconductor material 4H-SiC at near-threshold fluence, fs laser was repeatedly irradiated to SiC surface at different scanning velocities and scan times. The evolutions of surface morphologies were observed and discussed according to Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM) and Transmission Electron Microscope (TEM). Discontinuous zones were ablated in SiC surface after laser irradiation at near-threshold fluence 1.1 J/cm2. High spatial frequency rippled structures substantially shorter than the wavelength of incident fs laser were fabricated. The width of the ablated zones increased with lower scanning velocities and more scan times. The mechanism was discussed. Incubation effect occurred in the subsurface of SiC triggered inhomogeneous energy deposition accumulation, which was responsible for the discontinuous ablated zones. Moreover, an amorphous layer with a thickness of about 30 nm was observed in 4H-SiC surface where no ablation was induced after repeated irradiation. This was discussed and explained from the aspects of molecular dynamics simulations of fs laser irradiation to semiconductor materials.

Original languageEnglish
Pages (from-to)P29-P34
JournalECS Journal of Solid State Science and Technology
Volume7
Issue number2
DOIs
Publication statusPublished - 2018

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials

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