| 摘要 |
<p>A self-aligned bipolar transistor, which has a small base resistance and small emitter-base and collector-base capacitances and is operable at high speed, is characterised in that a low concentration collector region (8) made of single-crystal Si-Ge is formed by self-alignment between an intrinsic base (9) of single-crystal Si-Ge and a collector layer (3), and that an extrinsic base electrode (6) and the intrinsic base (9) are interconnected only through a doped external base (10). Due to the formation of the low concentration region (8) of single-crystal Si-Ge, no energy barrier is established at the collector-base interface, so that the transit time of the carriers charged front the emitter (15) is shortened. The connection between the intrinsic base (9) and the extrinsic base electrode (6) via the doped external base (10) results in a reduction of the base resistance. In addition, the self-aligned formation of the emitter-base-collector leads to a reduction in capacitance between the emitter and the base and also between the collector and the base. Accordingly, a high-speed bipolar transistor can be realised and thus, circuits using the transistor are operable at high speed. <IMAGE></p> |
