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Silicon carbide (SiC) is not only a strategic material critical to national defense, but also a cornerstone technology for the global automotive and energy industries. The very first step in SiC wafer manufacturing is slicing bulk-grown SiC ingots into thin wafers. The quality of this slicing process directly determines the efficiency and yield of subsequent thinning and polishing steps. However, conventional slicing methods often introduce cracks on the wafer surface and subsurface, which increases wafer breakage rates and drives up production costs. Therefore, minimizing surface damage during slicing is vital for advancing SiC device manufacturing technologies.

At present, SiC wafer slicing faces two major challenges:

1. High material loss with traditional multi-wire sawing.
   Due to the extreme hardness and brittleness of SiC, sawing and polishing are technically demanding, often leading to severe wafer warpage, cracks, and excessive material waste. According to Infineon’s data, traditional reciprocating diamond wire sawing methods achieve only ~50% material utilization at the slicing stage. After grinding and polishing, the effective yield can drop by as much as 75% (with a per-wafer total loss of ~250 μm), leaving a relatively low proportion of usable wafers.

2. Lengthy processing cycles and low throughput.
   International production statistics show that under continuous 24-hour operation, manufacturing 10,000 wafers requires approximately 273 days. Meeting market demand with wire saw technology therefore requires a massive number of machines and consumables. Moreover, the method results in poor surface roughness, significant contamination, and heavy environmental burdens (dust, wastewater, etc.).

To address these challenges, the research team led by Professor Xiu Xiangqian at Nanjing University has developed large-diameter SiC laser slicing equipment. By applying advanced laser slicing techniques, the system significantly reduces material loss while dramatically improving throughput. For instance, when processing a 20 mm SiC ingot, the number of wafers produced with laser slicing is more than double that achieved by conventional wire sawing. In addition, laser-sliced wafers exhibit superior geometric properties, and the wafer thickness can be reduced to as little as 200 μm, further increasing yield per ingot.

The competitive advantage of this project lies in its technological maturity. A prototype of the large-scale laser slicing equipment has already been developed and successfully demonstrated in:

• Slicing and thinning of 4–6 inch semi-insulating SiC wafers

• Slicing of 6-inch conductive SiC ingots

• Ongoing validation for 8-inch SiC ingot slicing

This system offers shorter slicing cycles, higher annual wafer output, and lower per-wafer material loss, achieving over 50% improvement in yield compared to conventional methods.

From a market perspective, large-diameter SiC laser slicing equipment is poised to become the core technology for 8-inch SiC wafer production. Currently, such equipment is almost exclusively imported from Japan, with high costs and potential export restrictions. Domestic demand for laser slicing/thinning equipment is projected to exceed 1,000 units, yet no mature domestic supplier exists today. The Nanjing University-developed system therefore holds substantial market potential and enormous economic value.

Beyond SiC, this laser slicing platform can also be extended to other advanced semiconductor and optical materials, including gallium nitride (GaN), gallium oxide (Ga₂O₃), and synthetic diamond, further broadening its industrial application.