| 摘要 |
PURPOSE:To sufficiently reduce a base expansion resistance by forming an active base region and a base contacting region in one diffusing step, and shortening the distance from the end of an emitter region to the contacting region within 1mum or shorter. CONSTITUTION:A low impurity density N type epitaxial layer 2 is grown on a high impurity density N type silicon substrate 1 to become a collector region. Then, a silicon oxide film is formed on the surface, and only a base region is removed. Then, a polycrystalline silicon and a silicon nitride film are sequentially superposed and formed. Thereafter, phosphorus or arsenic is implanted, and diffused to form an emitter region 5. Then, the silicon nitride film and the polycrystalline silicon film are all removed, boron ions are implanted, and heat treated to form a base contacting region 3 having a high impurity density and an active base region 4 having low impurity density and shallow diffusing depth. Eventually, aluminum electrode 6 is formed.
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