| 摘要 |
<p>Semiconductor device comprising a vertical transistor, for example of the PNP type, having a P substrate (1) forming the collector, with, at its surface, a N epitaxial layer (3) in which a P emitter region (15,16) is formed, the part (9) of the epitaxial layer (3) between the emitter (15,16) and collector (1) forming the base. In this vertical transistor, the current gain is very greatly increased, when the emitter is formed by a said first, lightly P-doped, partial emitter region, extending under an insulating layer (6), and a said second, heavily P<++>-doped, partial emitter region (16), extending under the emitter contact area (26) delimited by an opening in the insulating layer (6). The respective dopings and the thicknesses of the first (15) and the second (16) emitter regions are provided so that the first region is transparent to the electrons and the second forms a screen for the electrons. Moreover, the ratio of the areas of the two partial regions (Sox/Sm) is greater than 2, the area (Sm) of the second region (16) being chosen to be small. The various regions of the transistor are formed by very thin layers. The transistor may also be NPN. <IMAGE></p> |
