LPCVD silicon nitride is one of the most versatile thin films in MEMS fabrication, serving as a structural layer, a passivation layer, an etch mask, and a reliable dielectric. At Rogue Valley Microdevices, we deposit high-quality LPCVD silicon nitride on your wafers using the same production furnaces that support our U.S.-based MEMS foundry, giving you fab-grade films with the stress control your design demands. Silicon nitride deposition is part of our complete wafer services offering, backed by engineers with decades of experience developing and optimizing LPCVD nitride films. Its tensile stress, mechanical strength, and excellent dielectric properties also make LPCVD nitride valuable for balancing film stress within multilayer thin-film stacks. We offer three qualified LPCVD nitride films, each deposited for consistent thin-film performance and excellent wafer-level uniformity. Films deposit on both sides of the wafer: - Stoichiometric nitride: ≥800 MPa tensile stress; refractive index 2.00 ± 0.05 at 632.8 nm; maximum thickness 4500Å; primary applications: dielectric isolation, chemical passivation, hard etch masking - Low-stress nitride: <250 MPa tensile stress; refractive index 2.20 ± 0.05 at 632.8 nm; maximum thickness 2µm; primary applications: stress-matched structural layers, microfluidics, thin-film membranes - Super-low-stress nitride: <100 MPa tensile stress; refractive index 2.30 ± 0.05 at 632.8 nm; maximum thickness 4µm; primary applications: sensitive MEMS membranes, cantilevers, low-loss photonics Not sure which film fits your device? Our engineers help you select the right combination of stress and thickness for membranes, cantilevers, hard masks, and multilayer stacks, and advise on how the nitride integrates with the rest of your process flow. Stress classes map to devices. Super-low-stress (<100 MPa) suits sensitive membranes, cantilevers, and low-loss photonics; low-stress (<250 MPa) suits stress-matched structural layers and microfluidics; stoichiometric (≥800 MPa tensile) delivers dielectric isolation and hard etch masking — up to 4500Å stoichiometric or 2µm for the low-stress classes. We deposit LPCVD silicon nitride on 50.8mm, 76.2mm, 100mm, 125mm, 150mm, and 200mm wafers, including: - Silicon - Silicon-on-insulator (SOI) - Quartz (super-low-stress nitride only, due to thermal expansion mismatch) - Sapphire (quoted individually) - Other specialty materials by request Because LPCVD is a high-temperature process, wafers that already carry metal films are better served by our PECVD films, which deposit nitride and oxide at lower temperatures. Why Engineers Choose Our LPCVD Silicon Nitride: - Foundry-Grade Uniformity: Films grown on the same qualified furnaces that run our full MEMS production programs - Low Pinhole Density: Reliable dielectric isolation and stable electrical insulation - High Mechanical Strength: Tensile films suited to MEMS structural layers and membranes - Etch Mask Durability: LPCVD nitride is the standard masking layer for KOH silicon etching, holding up through prolonged wet etch processing - Superior Conformal Coverage: Consistent film thickness over complex, high-aspect-ratio structures - Double-Sided Deposition: LPCVD coats both wafer sides in a single run, useful for backside masking and stress balancing These properties make LPCVD silicon nitride wafers ideal for applications that demand robust thin-film performance under demanding mechanical, electrical, and environmental conditions. Silicon nitride thin films play a critical role in many microfabricated devices and semiconductor technologies. Our LPCVD nitride deposition combines with other wafer services, such as thermal oxidation, to support applications including: - MEMS pressure sensors - Accelerometers and inertial sensors - Microfluidic devices - Optical MEMS components - Low-loss optical waveguides for silicon photonics - Device passivation layers - Dielectric isolation structures - Membrane and diaphragm structures Because LPCVD silicon nitride films provide high tensile strength and low permeability, they are widely used for MEMS membranes, structural layers, and protective coatings in advanced microdevices. As a U.S.-based, ITAR-registered MEMS foundry, we support companies developing next-generation sensors, MEMS devices, and semiconductor technologies. Your nitride films are deposited in-house on the same qualified equipment used for device production, never brokered to a third party. Start with LPCVD silicon nitride wafers for prototyping, add complementary films such as PVD metal and dielectric films, and scale into full device fabrication without changing vendors or re-qualifying your films.
