| 摘要 |
A semiconductor device having an epitaxial layer (3) of one conductivity type formed on a semiconductor substrate (1) of the other conductivity type, a base region of the other conductivity type formed on the epitaxial layer to extend from a surface of the epitaxial layer to a predetermined depth, the base region including an intrinsic base region (8) and an external base region (7), an emitter region (12) of the one conductivity type formed in the intrinsic base region (8), and a pedestal collector region of the one conductivity type formed in a portion of the epitaxial layer which is immediately under the base region to correspond thereto, wherein the pedestal collector region comprises a plurality of layers of pedestal collector regions (102,103,104) which have an impurity concentration that changes in a direction of depth of the substrate and which are sequentially arranged in the direction of depth of the substrate. <IMAGE> |
