Enhancing 4H-SiC Lapping Performance: Diamond and Boron Carbide Composite Abrasives Effects on Material Removal and Subsurface Damage

Silicon carbide (SiC) substrates have been widely adopted in high-performance applications such as power electronics, optoelectronics, and semiconductors. However, achieving high-quality processing remains a formidable challenge due to SiC’s inherent hardness and brittleness. This study investigates the effects of diamond and boron carbide (B4C) abrasives on material removal rate (MRR) and surface roughness during the lapping of SiC substrates. The results demonstrate that the mix ratio of diamond to B4C significantly affects the roughness of the lapped substrates. Increasing B4C proportions results in lower Sa values. Nonetheless, excessive B4C powder leads to insufficient abrasive lapping force. Furthermore, finer B4C powder contributes to higher surface roughness and higher SiC removal rate. Additionally, the influence of different diamond powder sizes on the depth of subsurface damage (SSD) of lapped SiC substrates was evaluated using an atmospheric inductively coupled plasma (ICP) etching method. As the diamond particle size increased from 3 μm to 4 μm, the SSD depth rose from 1.56 μm to 2.16 μm. Furthermore, this study elucidates the lapping removal process of silicon carbide substrate from the mechanism, which can provide actionable guidance for refining lapping techniques in 4H-SiC substrate manufacturing.