Insights into Silicon Carbide: Properties, Production, and Prospects

Introduction

Silicon carbide (SiC) has emerged as a critical material in various high-tech industries due to its unique properties. This article delves into the specifics of SiC, covering its physical characteristics, global production capacity, and cost considerations.

Physical Properties

Silicon carbide boasts several remarkable physical properties that make it highly desirable for advanced applications:

1. High Refractive Index and Low Density: SiC has a refractive index exceeding 2.4, significantly higher than that of high-refractive glass, which typically has a refractive index of around 1.7 to 1.8. Despite this high refractive index, SiC maintains a relatively low density of approximately 3.2 g/cm³. In contrast, high-refractive glass requires the addition of heavy metals to achieve its refractive index, resulting in a much higher density—around 3.6 g/cm³ for a refractive index of 1.7-1.8, and over 4.5 g/cm³ for a refractive index of 2.0.

2. High Hardness: SiC is known for its exceptional hardness, making it suitable for applications requiring durable and scratch-resistant materials.

Global Production Capacity

The global production capacity for semi-insulating SiC is currently limited to fewer than 100,000 wafers annually. However, the production capacity for conductive SiC exceeds 800,000 wafers per year. While semi-insulating SiC is suitable for photonic waveguides, conductive SiC is not. Nevertheless, the production capacity for conductive SiC can be rapidly converted to produce semi-insulating SiC if needed.

Wafer Size and Yield

The size of SiC wafers directly impacts the yield of photonic waveguides:

• A 4-inch wafer can produce 1 photonic waveguide.

• A 6-inch wafer can yield 4 photonic waveguides.

• A 12-inch wafer can produce between 15 to 25 photonic waveguides.

Larger wafers offer improved economies of scale and higher yields, which is crucial for meeting the growing demand for SiC-based devices.

Cost Considerations

The cost of SiC wafers varies significantly based on their size:

• A 6-inch SiC wafer currently costs around 2,000 yuan.

• An 8-inch wafer costs approximately 5,000 to 6,000 yuan.

• A 12-inch wafer is estimated to cost around 10,000 yuan if produced.

These costs reflect the increasing complexity and resource requirements associated with larger wafer sizes.

Applications and Future Prospects

Silicon carbide's unique properties make it highly sought after for applications in optoelectronics, power electronics, and telecommunications. As technology advances and production processes become more refined, the demand for SiC is expected to grow, driving further innovations and cost reductions.

Conclusion

Silicon carbide represents a significant advancement in material science, offering a unique combination of high refractive index, low density, and high hardness. Despite current production limitations, the potential for SiC in various high-tech applications is immense, and ongoing research and development efforts are likely to unlock even more of its capabilities in the future.