摘要 |
<p>A bipolar junction transistor comprises a substrate (10), a lightly doped base region (12) on the substrate, a heavily doped base contact region (14) around the lightly doped base region, and an emitter (16) positioned above the lightly doped base region. By etching away the peripheral portion of the emitter (16), and desirably also a portion of the periphery of the lightly doped base region (12), one creates a planar junction (25) between emitter and base. This gives increased resistance to breakdown as compared with a curved junction and gives other benefits due to the increased separation (X' + Y) between the emitter (16) and the heavily doped base contact region (14).</p> |