## 1 Introduction  
Single-crystal silicon carbide (SiC) is widely used due to its excellent electrical, thermal, and mechanical properties resulting from a variety of features, which include a wide energy band gap, excellent thermal conductivity, high saturated electron drift velocity, and satisfactory chemical stability [1]. SiC is particularly suitable for high-performance devices such as high-power, high-temperature, and high-frequency electronic devices. However, a well-ordered SiC surface and a high removal rate are difficult to achieve due to the mechanical hardness and chemical inertness of SiC [2]. Chemical mechanical polishing (CMP) is the core technology used in semiconductor manufacturing, especially in ultra large scale integration (ULSI) manufacturing. CMP is regarded as the most effective technology to achieve ultra-smoothness without causing surface damage, during the ultra-precise machining of SiC crystal substrates [3; 4]. However, the material removal rate (MRR) in CMP is very low. Therefore, new methods must be developed in order to increase the MRR of SiC during polishing process. Several studies on the CMP of SiC have pursued in order to increase the MRR and verify the polishing mechanisms. [PERSON] _et al._[5] studied the effect of process parameter variations on the MRR of SiC by using commercial colloidal silica slurry and found the maximum MRR to be0.25 mm/h. In another work [6], the chemical and tribological conditions for tribochemical polishing of polycrystalline SiC were investigated in different oxidant solutions, and the surface properties were determined. The results showed that the material removal rate was 200-400 nm/h. [PERSON] and [PERSON] [7] augmented the MRR in CMP of SiC with an oxidizer-enriched colloidal silica slurry and a hybrid of specially treated sub-micron diamond and colloidal silica slurry (designated as CMP-D slurry). [PERSON] _et al._[8] used a mixture of a colloidal silica slurry and nanodiamond abrasive (designated as a mixed abrasive slurry (MAS)) to achieve superior MRR and a fine surface. Recent studies have reported that by using mixed abrasives in hybrid CMP, a superior MRR and high scratch reduction could be achieved. The MRR of SiC after CMP with MAS was approximately 550 nm/h. [PERSON] _et al._[9] proposed a novel abrasive polishing technique combined with the irradiation of atmospheric-pressure plasma, called plasma assisted polishing (PAP). This method afforded high-efficiency and high-integrity finishing on difficult-to-machine materials and resolved the low MRR of single-crystal SiC (\(<\)0.5 um/h). Some studies have examined the influence of polishing slurry characteristics, including pH, abrasive size and concentration, rotational velocity of the polishing platen and carrier, and polishing pressure on the MRR of the SiC crystal substrate based on the alumina abrasive in CMP. [PERSON] _et al._[10] proposed a surface planarization method for SiC substrates by using Fe abrasive particles and a hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)) solution. They found that the MRR of the 4H-SiC C-face surface was approximately 800 nm/h at a pressure of 0.06 MPa. [PERSON] _et al._[11] discussed the development of slurries based on silica abrasives that resulted in high amorphous SiC (a-SiC) removal rates (RRs). The ionic strength of the silica dispersion was found to play a significant role in enhancing material removal rate, while also providing very good post-polish surface-smoothness. This study proposes a novel fixed abrasive polishing pad composed of Fe and Al\({}_{2}\)O\({}_{3}\) particles impregnated in a polyurethane matrix. Four types of pads of various compositions, containing 1 wt % Fe particles, 1 wt % Al\({}_{2}\)O\({}_{3}\) particles, 1 wt % Fe/1 wt % Al\({}_{2}\)O\({}_{3}\) particles, and 1 wt % Fe/3 wt % Al\({}_{2}\)O\({}_{3}\) particles, were fabricated. A combination of loose and fixed polishing methods was explored to improve the polishing process.