Rogue Valley Microdevices delivers precision thermal oxidation services on silicon wafers, growing high-quality silicon dioxide layers for insulation, passivation, and process masking. Our thermal oxide wafers are produced in the same U.S.-based, ITAR-registered fab that builds MEMS devices for medical, industrial, and defense customers, so every oxide layer meets production standards from the first lot. During thermal oxidation, oxygen or steam reacts with the silicon surface at elevated furnace temperatures, converting the wafer surface into a dense silicon dioxide film. Because the oxide grows from the substrate itself rather than being deposited on top of it, thermal oxide delivers exceptional interface quality, uniform thickness, and excellent adhesion with low defect density. Thermal oxidation is part of our complete wafer services portfolio, supporting prototype development through volume production. Thermal Oxide Film Options and Wafer Sizes: We grow thermal oxide on 50.8mm, 76.2mm, 100mm, 125mm, 150mm, and 200mm silicon wafers. Grown, not deposited. Wafers sit in a high-temperature furnace with every face exposed — oxygen (dry) or steam (wet) converts the silicon surface itself into oxide, so the film grows both into and out of the original surface, coating both sides and edges from 500Å to 10µm. Dry Thermal Oxidation: Dry oxidation uses oxygen as the oxidizing species and produces dense, high-quality oxide films. Choose dry oxide when your device requires thin, high-precision dielectric layers. Thickness Range: 500Å to 5000Å. Common Applications: Thin, high-precision dielectric and electrical insulation layers. Dry Chlorinated Thermal Oxidation with a Forming Gas Anneal: Dry chlorinated thermal oxide helps eliminate mobile metal ions from the film, enabling your device to achieve its highest level of electrical performance. Adding a forming gas anneal (FGA) after oxidation passivates dangling bonds at the silicon interface. Dangling bonds can degrade the insulating properties of an oxide, so pairing the FGA with a chlorinated oxide delivers the maximum benefit of the process. Thickness Range: 500Å to 5000Å. Post-Processing Options: Forming gas anneal (FGA) to passivate dangling bonds. Common Applications: Devices requiring mobile metal ion neutralization for peak electrical performance. Wet Thermal Oxidation: Wet oxidation introduces water vapor to accelerate oxide growth, producing the thicker oxide layers required by many MEMS and optical applications. It grows oxide significantly faster than dry oxidation while maintaining excellent film uniformity. By tailoring oxidation conditions, including temperature and gas ratios, we precisely control oxide thickness and film properties for your application. Thickness Range: 1000Å to 10µm. Common Applications: Thick field oxides, DRIE etch masking, sacrificial release layers, waveguide cladding. Thick Thermal Oxide for MEMS and Optical Waveguide Fabrication: Many MEMS processes call for thick thermal oxide layers to support micromachining, device isolation, and advanced photonic structures. Using optimized wet oxidation, we grow oxide up to 10µm with strong wafer-level thickness uniformity and low defect density. In silicon photonics, thick thermal oxide commonly serves as the undercladding layer, optically isolating the waveguide core from the silicon substrate. After the waveguide material is deposited and patterned, additional oxide can be deposited or grown to form the overcladding, which protects the optical structure and stabilizes the refractive index environment surrounding the waveguide. Engineers commonly use thick thermal oxide for: - Deep silicon etch masking for DRIE and other micromachining processes - Electrical isolation and field oxide layers in sensors and integrated microdevices - Sacrificial layers used to release movable MEMS structures - Undercladding layers for LPCVD silicon nitride or doped oxide optical waveguides - Overcladding layers that encapsulate and protect integrated photonic structures - Protective layers during complex wafer processing steps Thermal Oxidation from a U.S.-Based, ITAR-Registered MEMS Foundry: Thermal oxidation is one part of our broader MEMS foundry and wafer processing capabilities. Our engineers integrate oxide growth with complementary thin-film deposition and micromachining steps, so your oxide arrives ready for whatever comes next in your flow. Why Choose Rogue Valley Microdevices for Thermal Oxidation: Foundry-Grade Film Integrity: Oxides grown on the same qualified furnaces that build medical, industrial, and defense microdevices, not a standalone film shop. Photonics Support: Thick wet oxides serving as undercladding and overcladding layers that isolate waveguide cores. Direct Engineering Collaboration: A direct line to the process engineers running your furnaces on thickness targets and film properties. Prototype Through Volume: Development lots to recurring production on the same qualified furnaces. What Thermal Oxide Wafers Are Used For: Engineers rely on thermally grown silicon dioxide to create reliable dielectric layers in MEMS devices and semiconductor technologies. Common uses include: - Electrical insulation layers - Surface passivation and environmental protection - Masking layers for silicon etch processes - Sacrificial layers used to release MEMS structures - Dielectric layers for sensors and integrated microelectronics Because oxidation transforms the silicon surface itself, the resulting layer forms a strong, stable interface with excellent adhesion, high dielectric strength, and lower defect density than many deposited dielectric films.
