| 摘要 |
PURPOSE:To reduce a section flowing through the surface of a base layer of collector currents, to prevent an effect of a surface recombination and to improve the characteristics of an integrated circuit by forming an emitter layer and a collector layer in a recessed section formed in a base region. CONSTITUTION:An n<+> region 2 is formed to one part of the surface of a p type silicon board 1 through diffusion, and an n layer 3 is formed on the region 2 through an epitaxial method. The recessed sections 7, 8 are formed to the n layer 3 through etching, and the p type emitter layer 4 and the p type collector layer 5 are formed from the bottoms of the recessed sections through diffusion. A p type isolation layer 6 is formed separately through diffusion, and an n<+> layer 9 for a base electrode is also formed through diffusion. Surface currents reduce largely because collector currents flow as shown in the arrow 10. Consequently, the surface recombination does not contribute to hFE-IC characteristics, hFE does not lower in a low-current region, and hFE is represented in flat characteristics extending over a wide range of the IC. Accordingly, an amplification of little strain can be executed by the transistor, and even minute currents can be treated. |
