Silicon carbide (SiC), as a third-generation semiconductor material, plays a crucial role in power electronics and high-frequency applications due to its excellent physical and chemical properties. However, the extreme hardness, high thermal resistance, and chemical inertness of SiC make its processing highly challenging, especially in wafer cutting. Efficient and precise wafer cutting is essential to ensuring the performance of SiC devices. This article provides an in-depth introduction to several mainstream SiC wafer cutting processes, analyzing their advantages, disadvantages, and applicable scenarios.

1. Diamond Wire Saw Cutting

Diamond wire saw cutting is the most widely used process for cutting SiC wafers. This method utilizes a high-speed wire coated with diamond particles to cut the crystal through mechanical grinding.

Advantages:

Suitable for cutting large SiC crystals;

Fast cutting speed, improving processing efficiency;

High cutting precision with minimal material waste.

Disadvantages:

Generates significant heat during cutting, which can lead to thermal damage;

Thick damage layer is produced, requiring subsequent polishing or etching to restore surface quality.

Applications: This process is widely used for large-scale wafer cutting, especially in high-volume production where efficiency is a key factor.

2. Laser Cutting

Laser cutting relies on a high-energy laser beam focused on the surface of the SiC, melting or vaporizing the material locally to achieve cutting. Due to its non-contact, high-precision characteristics, laser cutting is suitable for wafers with complex geometries.

Advantages:

Fast cutting speed, significantly reducing processing time;

No physical contact, minimizing mechanical damage;

Suitable for high-precision and complex shape cutting.

Disadvantages:

The thermal stress generated during laser cutting can cause micro-cracks in the material;

High equipment cost and expensive maintenance.

Applications: Laser cutting is typically used for high-precision, low-volume manufacturing, or for cutting wafers with complex shapes.

3. Plasma Cutting

Plasma cutting utilizes the high temperature generated by plasma to locally melt the material and blow it away, completing the cutting process. This method works well in high-temperature environments and is suitable for large SiC wafers.

Advantages:

High cutting precision, especially for large wafers;

Relatively fast cutting speed.

Disadvantages:

Generates significant heat during cutting, leading to potential thermal stress in the material;

Complex and expensive equipment with high maintenance requirements.

Applications: Plasma cutting is commonly used for large-size wafers or applications requiring high cutting precision, particularly in the power electronics field.

4. Mechanical Saw Cutting

Mechanical saw cutting is a traditional cutting process that uses circular saw blades or wire saws to cut SiC wafers through physical contact. While mature and reliable, this method tends to cause more damage when applied to hard materials like SiC.

Advantages:

Mature process with relatively low cost;

Suitable for medium to low precision cutting tasks.

Disadvantages:

Greater cutting damage, causing micro-cracks in the material;

High dust generation during the process, which may affect the working environment.

Applications: Mechanical saw cutting is suitable for low-cost processing with less stringent precision requirements or as a supplementary method for other cutting processes.

5. Electrical Discharge Machining (EDM)

Electrical discharge machining (EDM) removes material through pulsed discharge, achieving high-precision cutting of SiC wafers. Since it does not rely on physical contact, it causes minimal mechanical damage to the material.

Advantages:

High precision cutting, suitable for wafers with complex shapes;

Non-contact processing, avoiding mechanical stress-induced damage.

Disadvantages:

Slow cutting speed, making it less suitable for high-volume production;

Higher processing costs, especially for large wafers.

Applications: EDM is ideal for high-precision, small-batch processing of complex structures, often seen in specific research projects or high-end electronics manufacturing.

Conclusion

The choice of SiC wafer cutting process directly impacts both the efficiency of subsequent processing and the final quality of the wafers. Diamond wire saw cutting is well-suited for high-volume production, while laser and plasma technologies shine in high-precision and complex-shape applications. EDM and mechanical saw cutting have their respective advantages: the former excels in high-precision applications, and the latter serves as a low-cost option. The choice of cutting process should be based on the specific application, processing requirements, and economic considerations.

As semiconductor manufacturing technology continues to advance, cutting techniques for SiC wafers are also evolving. In the future, we may see more innovative cutting methods that further enhance processing efficiency and quality.