Recently, Nanjing University has successfully developed large-scale silicon carbide (SiC) laser slicing equipment and technology, marking a significant advancement in the field of third-generation semiconductor material processing equipment in China. This technology not only resolves the high material loss issue in traditional cutting techniques but also significantly enhances production efficiency, making a significant contribution to the development of silicon carbide device manufacturing technology.
Silicon carbide (SiC), as a key strategic material, is crucial for national defense security, the global automotive industry, and the energy industry. The new technology developed by Nanjing University has made significant improvements in the slicing performance during the silicon carbide single crystal processing process. It can effectively control the surface crack damage of the wafer, thereby improving the subsequent thinning and polishing processing level.
"Traditional multi-wire cutting technology has high material loss and long processing cycles when processing silicon carbide, which not only increases production costs but also limits capacity," the project leader explained. The material utilization rate of the traditional method in the cutting link is only 50%, and the material loss after polishing and grinding is as high as 75%.
To overcome these challenges, the technical team at Nanjing University adopted laser slicing equipment, significantly reducing material loss and improving production efficiency. For example, a 20mm SiC ingot can produce more than 50 wafers using laser slicing technology, compared to 30 wafers of 350 microns produced by traditional wire saw technology. After optimizing wafer geometric characteristics, the thickness of a single wafer can be reduced to 200 microns, allowing a single ingot to produce more than 80 wafers.
In addition, the laser slicing equipment developed by Nanjing University also has a significant advantage in cutting time. The single slice cutting time of a 6-inch semi-insulating/conductive silicon carbide ingot does not exceed 15 minutes, and the annual output of a single device can reach more than 30,000 pieces. The loss per piece is effectively controlled, with the loss of a semi-insulating silicon carbide ingot controlled within 30 microns and conductive type within 60 microns, increasing the yield rate by more than 50%.
In terms of market application prospects, large-scale silicon carbide laser slicing equipment will become the core equipment for slicing 8-inch silicon carbide ingots in the future. At present, only Japan can provide such equipment, which is expensive and embargoed against China. The domestic demand exceeds 1,000 units, and the equipment developed by Nanjing University can not only be used for silicon carbide ingot cutting and wafer thinning but also for laser processing of materials such as gallium nitride, gallium oxide, and diamond, showing broad market application prospects.
