Pushing the Limits of MEMS Performance: Why Low-Stress Silicon Nitride Films Are the Key Choice?

In the rapidly evolving field of MEMS (Micro-Electro-Mechanical Systems), the performance and reliability of devices—from pressure sensors and microphones to optical mirrors—are directly determined by their core materials. Among various thin-film materials, low-stress silicon nitride films are increasingly becoming the preferred choice for high-end MEMS designs. This article explores the reasons behind this trend and the new demands it places on MEMS silicon nitride film foundry services.

1. Exceptional Mechanical and Barrier Properties Silicon nitride films are renowned for their extreme hardness, excellent chemical inertness, and superior insulating properties. In MEMS, they are commonly used as structural layers, passivation layers, or sacrificial layers. Compared to other materials, they offer better long-term stability and environmental resistance, ensuring device reliability under harsh conditions.

2. Stress Control: The Decisive Factor for Performance Film “intrinsic stress” is a critical challenge in MEMS fabrication. Excessive compressive or tensile stress can cause film warping, delamination, or even micro-structure fracture. Hence, the value of low-stress silicon nitride films becomes paramount. Through precise control of parameters in advanced deposition processes (such as LPCVD or PECVD), films with extremely low stress and excellent uniformity can be achieved, enabling the fabrication of flatter, more sensitive, and longer-lasting MEMS devices.

3. Core Requirements for Foundry Services For clients seeking silicon nitride film foundry services, process capability is key. An excellent foundry partner must be able to:

• Provide customized stress control:  Precisely tune the process according to the client’s specific device      design (e.g., film thickness, pattern dimensions) to deliver target stress      values (as low as tens of MPa or near zero).

• Guarantee superior uniformity and consistency: Ensure highly consistent film properties across the entire      wafer and from wafer to wafer, which is crucial for production yield.

• Ensure compatibility with complex process integration: The deposition and etching of silicon nitride films must be      perfectly compatible with preceding and subsequent steps without affecting  other components.

Conclusion: Choosing a foundry partner specializing in low-stress silicon nitride film processes is a vital step toward high-performance, high-reliability MEMS products. Our company has deep expertise in this field, offering comprehensive MEMS silicon nitride film foundry solutions from process development to volume production, committed to helping global clients realize their most advanced device designs.