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    Review of 'Marrying Medicine and Materials: Artemisinin (Qinghaosu) Particle is Soft Enough for Scratching Hard SiC Wafer in Water'

    Marrying Medicine and Materials: Artemisinin (Qinghaosu) Particle is Soft Enough for Scratching Hard SiC Wafer in WaterCrossref
    Average rating:
        Rated 5 of 5.
    Level of importance:
        Rated 5 of 5.
    Level of validity:
        Rated 5 of 5.
    Level of completeness:
        Rated 4 of 5.
    Level of comprehensibility:
        Rated 5 of 5.
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    Reviewed article

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    • Abstract: found
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    Marrying Medicine and Materials: Artemisinin (Qinghaosu) Particle is Soft Enough for Scratching Hard SiC Wafer in Water

    Silicon carbide (SiC) single crystals, along with sapphire and silicon, are one of most important substrates for high-brightness LED fabrications. Owing to extremely high hardness (Mohs’ scale of 9.5) and chemical inertness, the polishing rate of SiC with conventional chemical mechanical polishing (CMP) methods is not high, and surface scratches are also inevitable because of using slurry containing hard abrasives such as silica particles. Here artemisinin (Qinghaosu) crystals, very soft molecular solids, were found, for the first time to the best of our knowledge, to effectively polish SiC wafers even in pure water as demonstrated by proof-of-concept scratching experiments using atomic force microscopy (AFM). The underlying mechanism is attributed to activated oxidation of SiC by mechanically released reactive ·OH free radicals from the endoperoxide bridges. The preliminary results reported here have important implications for developing novel alternative green and scratch-free polishing methods for hard-brittle substrates including SiC and others.

      Review information

      This work has been published open access under Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Conditions, terms of use and publishing policy can be found at www.scienceopen.com.

      chemical mechanical polishing,Silicon carbide,oxidation,atomic force microscopy,artemisinin,hydroxyl free radical

      Review text

      In general, this is a well written and interesting article which needs to be published. In this work, the authors presented a novel method for polishing SiC wafers effectively even in pure water using artemisinin (Qinghaosu) crystals. AFM was employed to conduct scratching tests to demonstrate the polishing mechanism of this proposed method. However, there are a few minor issues to be addressed.

      1. In the section of “AFM scratching test using artemisinin-modified AFM probe in water”, “in water (with a quartz liquid cell)” (5th lines of this section) is better to be defined as “de-ionized water”.
      2. In the same section, the resolution of each scratching test (such as 256×256 or 512×512) should be given.
      3. In the first sentence of Page 3, the word “and” (NaOH and H2SO4) should be changed into “or”.
      4. In Fig. 2 (c), the horizontal axis of Line 2 should be “y (μm)”.
      5. In the section of “Mechanism discussion: decomposition of SiC mediated by mechanically activated OH free radicals in water”, I think more discussions of mechanical-chemical effects on the machining process could be considered.


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