| With the development of 5G communication,driverless and other emerging technologies,higher requirements are put forward for the development and manufacturing of semiconductor materials.As a typical third-generation semiconductor material,single crystal SiC has wider band gap,higher breakdown electric field,electron mobility and thermal conductivity than traditional semiconductor materials（such as silicon,gallium arsenide,etc.）,which has broad application prospects in high temperature,high frequency and radiation resistant devices.However,because of its high hardness,high brittleness and very stable chemical properties,it is very difficult to finish the surface with high quality and high efficiency.This paper based on the principle of magnetic abrasive orientation and solid-state Fenton reaction a method of abrasive orientation solid-state reaction lapping is proposed in this paper.The magnetic particles Fe3O4 can not only orientate and hold the abrasive under the action of magnetic field,but also have solid-state Fenton reaction with SiC to prepare lapping and polishing plate,so as to improve the lapping and polishing efficiency and processing quality of single crystal SiC.A series of fixed abrasive plates with different ratios of abrasives were prepared by this method.The orientation law and control method of the formed abrasives were observed,and the corresponding relationship between the magnetic field intensity and the composition of the plate was studied.The lapping and polishing experiments were carried out to study the promoting effects of abrasive orientation,solid-state reaction and their synergism in the process of SiC lapping.The processing differences between the C surface and the Si surface were analyzed,and the material removal ratio of various factors in the process of abrasive orientation solid-state reaction lapping was also studied.The results show that the material removal rate of C and Si surfaces of single crystal SiC increases by 60.23%and 111.19%respectively,and the surface roughness Ra decreases by 15.68%and 85.24%respectively.The surface roughness Ra decreased by 73.98%and 16.51%,respectively.The synergistic effect of the two can increase the material removal rate by 100%and 144.55%respectively,and reduce the surface roughness Ra by 345.83%and 118.78%respectively.Under the combined action of abrasive orientation and solid state reaction,the material removal rate of C-face is 28.42%higher than that of Si-face,and the surface roughness is 206.94%lower.Mechanical removal is the main process in abrasive oriented solid state reaction machining,while solid state reaction is weak in lapping process.The influence of the composition parameters and the process parameters on the processing effect were systematically studied.The processing performance of the abrasive directional solid state reaction consolidation abrasive plate was investigated to obtain the better process parameters.The results show that the minimum surface roughness of C-face and Si-face are 0.76 nm and 0.90 nm,respectively,after 40 min of abrasion-oriented solid-state reaction lapping of single crystal SiC with initial roughness of about Ra100 nm.Abrasive oriented solid state reaction lapping is a process of interaction between chemical corrosion and mechanical removal.In the lapping process,chemical action can not only speed up the removal of abrasive materials,reduce the cutting force during mechanical removal,optimize the surface quality of SiC wafer,but also change the structure of the lapping plate and affect the wear of the lapping plate.By controlling the dynamic balance between chemical corrosion and mechanical removal in the lapping process,the SiC material removal process can be coupled with the wear of the lapping plate,which is helpful to improve the performance of the lapping plate and realize the high efficiency and low damage lapping of SiC materials. |
