| 摘要 |
<p>A heterojunction bipolar transistor having a planar surface topology, reduced lateral dimensions and a base electrode (40) aligned to both the emitter (38) and collector (26,36) electrodes is fabricated by forming sub-collector (12), collector (14), base (16) and one or more emitter (18,20) layers on a substrate (10). An opening (24) extending to the sub-collector layer (12) is then formed and a first portion (26) of the collector electrode (26,36) is formed therein so that the sidewalls of the opening (24) are not contacted by the first portion (26). Dielectric material (30) is then formed between the sidewalls of the opening (24) and the first portion (26) of the collector electrode (26,36). A second portion (36) of the collector electrode (26,36) then formed on the first portion (26) of the collector electrode (26,36) along with an emitter electrode (38) so that the second portion (36) of the collector electrode (26,36) and the emitter electrode (38) are substantially planar. After then exposing the base layer (16), the self-aligned base electrode (40) is formed between the second portion (36) of the collector electrode (26,36) and the emitter electrode (38).</p> |
