A high quality and ultraviolet-light transparent (UV-transparent) plasma enhanced chemical vapor deposition (PECVD) silicon nitride (SiNx) film is developed to form passivation layer for non-volatile memory devices. Comparing to the conventional PECVD SiNx film known to have tensile stress and opacity to ultraviolet-light (UV-light), the proposed SiNx film with very low compressive stress (<1 x 109 dyn/cm2) and excellent UV-transmit-tance (>70% for 1.6 μm-thick film) can be achieved. The film stress is strongly related to RF input power during deposition process. The UV-transmittance is influenced by pressure and S1H4/NH3 flow ratio. It is also shown that the UV-transmittance is closely correlated to refractive index (RI), film density as well as N/Si ratio inside the film. This SiNx film has been successfully applied to erasable programming read-only memory (EPROM’s) devices, and very good UV-erasability and reliability performances are demonstrated.