| 摘要 |
PURPOSE:To obtain the powder transistor of high ASO (area of safety operation) resistivity by a method wherein a density difference in lateral direction is given to the impurity density region of the base surface on the emitter circumference in such a manner that the distribution of current applied to the base from an emitter may be made uniform. CONSTITUTION:A low density p-diffusion layer 3 is provided between an emitter n<+> layer 7 and a contact p<+> layer 5 leaving a sufficient interval. After the SiO2 film on the surface has been photoetched by contact, solder is formed by performing the method such as electroplating and the like through the intermediary of the contact metal film of Ni or the like, a base B and an emitter E solder electrode 8 are formed, and an npn transistor is completed. The contact p<+> layer 5 is not present in the vicinity of the emitterdiffused n<+> layer 7, and the structure in which a p<+> layer is provided only on the contact part with the base electrode is obtained. Accordingly, the current applied to the base from the emitter is made uniform in lateral and longitudinal directions by suppressing the concentration of surface current by the low density p<-> layer 3, which functions as a resistor, located between the p<+> layer 5 and the n<+> layer 7, and the resistivity of ASO can be improved.
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