The Effects of Strong Oxidizing Slurry and Processing Atmosphere on Double-Sided CMP of SiC Wafer

Abstract

In order to achieve high removal rate and high-quality processing on SiC wafer, we carried out the CMP processing experiment with the new type CMP machine (Bell-jar) by using the slurry with the addition of strong oxidant (KMnO4). It was found that the high speed CMP processing was achieved by controlling the concentration of KMnO4 in the slurry, the pH of slurry and the processing atmosphere. By using the slurry with the addition of KMnO4 of 0.1mol/L, the removal rate was the fastest up to 1019nm/h in the fixed pH of 6. By use of the slurry of pH 3, the removal rate of C-face of SiC wafer was 1695nm/h On the other hand, the fastest removal rate of Si-face of SiC wafer was only 51nm/h by using the slurry whose pH is 7. In the open air atmosphere, the removal rate was 915nm/h, which was higher than that at the higher and lower atmospheric pressure.