Effect of Mn (II) Ion on Abrasive-Free Polishing of Hard Disk Substrate

With high requirement setting for hard disk substrate surface quality, abrasive-free polishing (AFP) has attracted more researchers’ attention. In this paper, the influence of Mn (Ⅱ) ion on AFP of hard disk substrate in the H2O2based slurry was investigated. The experiments results show that Mn (Ⅱ) ion can effectively increase the material remove rate (MRR) and improve the planarization of hard disk substrate. Furthermore, the acting mechanism of Mn (Ⅱ) ion in AFP of hard disk substrate was analyzed. The electron spin-resonance spectroscopy (EPR) analysis shows that Mn (Ⅱ) ion in the H2O2based slurry not only can increase the concentration of ·OH free radical, but also can make H2O2decompose to ·O2–free radical. These free radicals can accelerate the chemical etching and increase the MRR of hard disk substrate.

Effect of AIBA on Abrasive-Free Polishing of Hard Disk Substrate with Peroxyacetic Acid System Slurry

In the present study, the effect of 2, 2`-Azobis (2-methylpropionamidine) dihydrochloride (AIBA) on the abrasive-free polishing (AFP) of hard disk substrate was investigated. Polishing experiment results indicate that the material removal rate (MRR) of hard disk substrate polished in slurry containing AIBA and peroxyacetic acid (PAA) is obviously higher than that without AIBA. Furthermore, the acting mechanism of AIBA in AFP of hard disk substrate was analyzed. Auger electron spectrometer results demonstrate that the oxidation reaction occurred on the surface and formed a passivation layer. The potentiodynamic polarization tests show that AIBA can increase the corrosion rate of the hard disk substrate in PAA-based slurry, and accelerate the dissolution reaction of oxidation film, which lead to the improved MRR in AFP process.

Abrasive-Free Chemical Polishing of Hard Disk Substrate with Benzoyl Peroxide-H2O2 Slurry

The effect of benzoyl peroxide (BPO) as an initiator in H2O2slurry for abrasive-free chemical polishing of hard disk substrate was investigated. The results of abrasive-free polishing tests show that the introduction of BPO increases material removal rate (MRR) and decreases the value of Roughness (Ra). To further investigate the mechanism of abrasive-free polishing, electron spin-resonance spectroscopy (EPR) tests, auger electron spectrometer (AES) and electrochemical tests were conducted. Electron spin-resonance spectroscopy (EPR) tests show the concentration of radicals increase and promote the reaction on the surface of hard disk substrate. Auger electron spectrometer (AES) and electrochemical tests indicate chemical changes happen on the surface of hard disk substrate, and the formed oxide film may be sparse or porous. The results imply that the introduction of BPO can effectively improve the effect of abrasive-free polishing.