| 摘要 |
PURPOSE:To form with high reproducibily a base electrode possessing an excellent ohmic contact, by interrupting the growth of a base layer halfway, forming selectively a mask, and forming, after the growth is ended, a base electrode on the base layer surface covered by the mask. CONSTITUTION:A base layer 4 is groven while doping is performed. While interrupting the growth, a mask of SiO2 film is selectively formed on the surface. As to the surface of an exposed base layer, the growth of a base layer 5 is ended by the same procedure. After that, a base electrode 10 is formed on the surface which is formed at the time of interrupting the growth. Thereby a base electrode 10 can be formed with high reproducibily. This electrode exhibits an excellent ohmic contact with a very thin base layer of low sheet resistance, without destructing a collector layer 3. Consequently, the bipolar semiconductor device of this invention is available for high speed operation, because the base resistance can be suppressed low.
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