A new fabrication method of low stress PECVD SiNx layers for biomedical applications

A new fabrication method to produce low residual stress PECVD SiNx layers at high deposition rates was developed and their biomedical applications were reported in this paper. This new method employed up to 600 W high power to fabricate low stress SiNx layers in high frequency (13.56 MHz). By adjusting the composition of reactant gases, the residual stress can be lowered to 4 MPa and high deposition rate up to 320 nm/min can be achieved. In addition, this paper also investigated the influence of other important parameter, such as pressure, power and gases flow rates. Moreover, by using this optimized process, an 11 μm thick low stress SiNx layer was produced, which will be used to fabricate large window area for cell culture. Finally, a successful cell culture test involving cultivating mouse stem cells onto the porous membrane made of these low stress PECVD SiNx layers indicated that these layers are biocompatible and are suitable for biomedical applications.