Chemical mechanical polishing of silicon carbide (SiC) based on coupling effect of ultrasonic vibration and catalysis

Abstract

Polishing SiC is a difficult task due to its exceptional chemical stability and high hardness. While the strong catalytic performance resulting from the coupling effect of ultrasonic vibration and catalysis is well-known, there have been limited studies on its effectiveness for SiC chemical mechanical polishing. To address this gap, we present a novel approach that utilizes the coupling of ultrasonic vibration and catalysis for SiC polishing. The hydroxyl free radical (*OH) generated by coupling effect is analyzed using ultraviolet-visible spectrophotometry (UV–VIS) to screen for a catalyst that matches ultrasonic vibration and establish a high-performance catalytic coupling system. The use of ultrasonic vibration in SiC polishing results in a significant increase in catalytic efficiency, with a doubling effect observed. Additionally, the catalyst itself increases ultrasonic efficiency by 43.1 %, leading to a substantial improvement in material removal rate (MRR). We study the impact of the placement of the ultrasonic vibration device on MRR and evaluate the performance of the coupling system used for polishing. Also, we delved into the removal mechanism of SiC by utilizing XPS and nyquist plots. Our findings reveal a maximum MRR of 214.6 nm/h, which improves the efficiency of commercial slurry by 80.0 %. Furthermore, the proposed strategy increases the MRR of commercial slurry by more than 70 % in the time range of 0–1 h, 1–2 h, and 0–2 h. The surface roughness (Ra) measured by AFM using a scanning area of 1 × 1 µm2 at sub-angstrom scale (Ra=0.0627 nm) is achieved. This study significantly improves the polishing efficiency of commercial slurry and has great application prospects.