| 摘要 |
PURPOSE:To reduce the area occupied by collector connection and separation distance between elements and also reduce collector resistance by providing a groove reaching the bottom surface of N<+> buried layer on a Si substrate, forming an element separating insulation film to the bottom part of groove and connecting the side surface of N<+> type buried layer to the collector region with external collector electrode provided on the insulation film. CONSTITUTION:Si is selectively diffused to a P type Si substrate 1 by thermal diffusing method to form the N<+> type buried layers 21 and 22, the epitaxial layer 4, SiO2 film 33, Si3N4 film 34 are sequentially formed thereon and the Si substrate 1 is etched in the depth of 2 mum with the stacked insulating films 33 to 35 used as the mask. The SiO2 film 35, Si3N4 film 34, SiO2 film 33 formed on the surface of projecting region of Si substrate are removed by the wet etching to form the emitter regions 71 and 72. Thereby, the electrodes and wirings including base electrode 91, emitter electrodes 81, 82 and collector electrode 102 can be formed.
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