Process Control of Buried Layer Epitaxy by Barrel Type Furnace

Though the quality of epitaxial wafer prepared by barrel type epitaxial furnace is inferior to that by traditional single wafer furnace, it has a series of advantages such as high yield and low cost. The key issues and difficulties of the epitaxy process for buried layers IC wafers prepared by barrel type epitaxial furnace were discussed. By optimizing the epitaxy process parameters and tightly controlling the production procedure such as cleaning and inspecting, barrel type epitaxial furnace can meet the special requirement for buried layer epitaxial process. The characteristics of the epilayers prepared by barrel type epitaxial furnace were close or equivalent to that by single wafer furnace. The ways to suppress the auto doping in the double buried layer epitaxial process were introduced. The ideal transition width of the epilayers was obtained by the two-step epitaxy.