| 摘要 |
PURPOSE: A heterojunction bipolar transistor and a method for manufacturing the heterojunction bipolar transistor are provided to improve high speed characteristic of the device by removing parasitic effect between emitters and bases. CONSTITUTION: The heterojunction bipolar transistor manufacturing method includes following steps. At first, a cushion layer, an auxiliary collector layer, a base layer, an emitter layer and an emitter cap layer are sequentially grown to form an HBT(heterojunction bipolar transistor) epi-structure on a semiconductor substrate. Then, a 3-layer metallic layer(18) is vaporized on the portion of the HBT epi-structure to form an emitter ohmic contact. At third, overall emitter cap layer and a portion of the emitter layer is etched by using the 3-layer metallic layer as a mask and a thin emitter layer remains. Then, the emitter layer is removed by a base electrode pattern and a base electrode is formed. At fifth, the emitter layer, base layer and the collector layer are etched to form a collector electrode on the auxiliary collector layer to define a device isolation region. Then, each electrodes is wired to form the device.
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