Fabrication of SiN_x Thin Film of Micro Dielectric Barrier Discharge Reactor for Maskless Nanoscale Etching

The prevention of glow-to-arc transition exhibited by micro dielectric barrier discharge (MDBD), as well as its long lifetime, has generated much excitement across a variety of applications. Silicon nitride (SiN_x) is often used as a dielectric barrier layer in DBD due to its excellent chemical inertness and high electrical permittivity. However, during fabrication of the MDBD devices with multilayer films for maskless nano etching, the residual stress-induced deformation may bring cracks or wrinkles of the devices after depositing SiN_x by plasma enhanced chemical vapor deposition (PECVD). Considering that the residual stress of SiN_x can be tailored from compressive stress to tensile stress under different PECVD deposition parameters, in order to minimize the stress-induced deformation and avoid cracks or wrinkles of the MDBD device, we experimentally measured stress in each thin film of a MDBD device, then used numerical simulation to analyze and obtain the minimum deformation of multilayer films when the intrinsic stress of SiN_x is -200 MPa compressive stress. The stress of SiN_x can be tailored to the desired value by tuning the deposition parameters of the SiN_x film, such as the silane (SiH₄)⁻ammonia (NH₃) flow ratio, radio frequency (RF) power, chamber pressure, and deposition temperature. Finally, we used the optimum PECVD process parameters to successfully fabricate a MDBD device with good quality.