Accelerated C-face polishing of silicon carbide by alkaline polishing slurries with Fe3O4 catalysts. Issue 6 (December 2021)

• Record Type: Journal Article
• Authors: Wang, Xuehan; Chen, Jiapeng; Bu, Zhengzheng; Wang, Hanqiang; Wang, Wenjun; Li, Weimin; Sun, Tao
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 6(2021)
• Publication Date: 2021-12
• Subjects: Silicon carbide (SiC) -- Chemical mechanical polishing (CMP) -- Catalyst -- ·OH radicals -- Zeta potential -- pH; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.106863
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: As a third-generation semiconductor material, Silicon carbide (SiC) excels in extraordinary physical and chemical properties, which makes, in turn, it hard to process. The strong oxidizing species·OH produced by the Fenton reaction has been effectively applied in the chemical mechanical polishing (CMP) of single-crystal SiC. In order to expand the applicable pH range of Fenton reaction, magnetic recoverable Fe3 O4 nanocatalysts were prepared in this paper, and the Fenton system was successfully applied to SiC polishing in alkaline silica slurry, which significantly improved the material removal rate (MRR). UV–vis spectroscopy curves prove that in a H2 O2 containing slurry, more·OH radicals were produced at pH 2.5 than that at pH 9.0 during Fe3 O4 catalyst-assisted polishing, which is consistent with conventional wisdom about Fenton Reaction. Surprisingly, MRR of SiC wafer up to 632 nm/h was achieved at pH 9.0 instead of 2.5 using the same slurry. A detailed hypothesis is presented to elucidate the material removal mechanism of the Fenton reaction system on SiC polishing. Graphical Abstract: ga1 Highlights: Material removal mechanisms under different slurry pH are hypothesized. Hydroxyl radicals does not directly correlate to MRR in C-face polishing of SiC in alkaline polishing slurries. The CMP mechanisms for SiC are explored by XPS and UV–vis measurements of polished SiC surface.