1、 Is it technically feasible?

Lattice mismatch&thermal expansion difference

The lattice constants of SiC and Si differ by about 20%

The thermal expansion coefficient is also mismatched (SiC: 4.7 × 10 ⁻⁶/K vs Si: 2.6 × 10 ⁻⁶/K)

This means that during high-temperature epitaxial growth, problems such as cracks, stress concentration, and defect accumulation are prone to occur.

Buffer layer technology is key

GaN can achieve large-scale production on silicon substrates by relying on multi-layer buffer structures (such as AlN and GaN intermediate layers)

Similarly, 3C SiC epitaxial+Stip Graded buffer layer may become a new pathway to unlock SiC growth

Craft reference

GaN on Si has solved the problems of warping and cracking through process optimization, such as growth rate and temperature control

SiC epitaxy can also gradually break through technological bottlenecks by controlling thickness, interlayer transitions, and other means

2、 Is it economically cost-effective?

✅  Significant cost reduction

The price of Si wafers is much lower than that of SiC, and the equipment is also more versatile, with a lot of room for cost reduction

The successful experience similar to GaN on Si shows that low cost and compatibility with existing production lines are the key to achieving industrialization

✅  High device friendliness

Si substrate compatible with mainstream MOCVD equipment

Can use mature CMOS process platform to reduce the threshold for introducing new processes

3、 Is it useful in the application?

Suitable for low to medium power and high frequency scenarios

3C SiC has high electron mobility and is suitable for high-frequency and low-power scenarios such as radio frequency and fast charging

Compared to traditional Si devices, it has more advantages in thermal stability and frequency response

Assist SiC Si monolithic integration

Growing SiC on Si substrate helps integrate power switches and control circuits on a single wafer

Drawing on the chip integration solution of GaN, laying the foundation for SiC in "power+intelligence" integrated devices

4、 Current limitations and future prospects

Main challenges

Crystal defects: Currently, the growth quality is still inferior to that of native SiC substrates

Heat dissipation issue: The low thermal conductivity of Si limits high-power applications

Process maturity: still in the research and development/demonstration stage

Development prospects

By drawing on the successful path of GaN on Si and optimizing the buffer layer structure and growth process, it is expected to significantly improve the epitaxial quality

Packaging and system level design optimization will further compensate for heat dissipation and reliability issues

Si on SiC will gradually move towards commercialization for low to medium voltage, high frequency, and low-cost application scenarios

In summary:

Growing silicon carbide wafers on silicon substrates is a breakthrough path in the industry that presents significant technological challenges but has even greater potential.

Although there is still a certain distance from widespread application, it provides a new possibility to break down cost barriers and achieve the popularization of high-performance power devices. With the continuous evolution of materials, processes, and equipment, SiC epitaxy on silicon substrates may experience an explosion in the low to medium power market.