Discussion on the lapping and polishing process of 4H-SiC wafer

In order to achieve a high quality silicon carbide (SiC) film, the lapping and polishing process scheme was introduced in this paper. The ductile iron was utilized as lapping disc material, which can quickly thin the SiC wafer to the film of uniform thickness. After three-step lapping process, the thickness of the SiC wafer was reduced to 35 ± 4μm. In the process of polishing, a rough polishing and a fine polishing were studied by selecting suitable polishing liquid, polishing pad and parameters. The results show that the lapping and polishing procedure can realize large area and high quality SiC films: the film thickness, 30 ± 2μm and the surface roughness RMS, 0.69 nm.