Plasma Enhanced Chemical Vapor Deposition (PECVD) nitride is a low-temperature deposition process performed inside an RF plasma reactor. Silane (SiH₄) together with ammonia (NH₃) or nitrogen (N₂) is introduced into the chamber, where radio-frequency power generates a plasma that dissociates the precursor gases into highly reactive species. These species react at the wafer surface to deposit a silicon nitride film at approximately 200 to 400 °C. Because the plasma supplies the activation energy, deposition occurs well below the temperature limits of aluminum interconnects, temperature-sensitive materials, and completed device structures. The deposited film is a silicon-rich, hydrogenated nitride (SiNₓ:H) that contains significant bonded hydrogen and is slightly less dense than LPCVD nitride. In exchange, its film stress can be tuned from compressive to tensile through deposition parameters, and its refractive index can be adjusted for optical applications. Because the wafer rests on a temperature-controlled chuck or electrode that shields the backside from the plasma, PECVD nitride is typically a front-side process. Rogue Valley Microdevices deposits PECVD silicon nitride in thicknesses up to 2µm at low temperature, with a customized refractive index or film stress, and also offers PECVD silicon oxynitride (SiON) up to 4µm for optical and dielectric applications. PECVD silicon nitride: Up to 2µm, low temperature, customized refractive index or film stress. PECVD silicon oxynitride (SiON): Up to 4µm, targeted refractive index or film stress, low-temperature option below 350 °C. Typical Applications: Final passivation; Device encapsulation; Moisture and scratch protection; Interlayer dielectric (ILD); Anti-reflective and optical coatings; Low-temperature insulation over metal. Thickness at RVM: 300Å to 2µm.
