Alpha 303 i H

Thermal and diffusion furnaces are batch-processing tools that expose wafers to precisely controlled high temperatures and reactive gases. Such furnaces perform critical thermal steps including oxidation, diffusion doping, and chemical vapor deposition.

The Alpha 303 i H is a vertical furnace, a common architecture for thermal batch processing. Wafers are loaded into a quartz boat and inserted into a vertical quartz tube surrounded by heating elements.

The furnace controls temperature ramps and gas flows to achieve uniform processing across all wafers in the batch. Process gases are introduced at the top of the tube and exhausted at the bottom, with the wafer boat rotating to enhance uniformity.

Thermal furnaces like the Alpha 303 i H are used after photolithography and etch steps to grow oxides, deposit thin films, or diffuse dopants into the silicon substrate. The batch nature makes them suitable for high-volume manufacturing of mature-node devices.

Downstream processes include gate oxidation, source/drain annealing, and dielectric film formation. Upstream processes typically involve wafer cleaning and lithographic patterning.

The Alpha 303 i H is applied in semiconductor fabrication for thermal oxidation of silicon wafers, diffusion of dopants such as boron and phosphorus, and low-pressure chemical vapor deposition of silicon dioxide and silicon nitride films.