摘要 |
A lateral bipolar transistor includes trench emitter and trench collector regions to form ultra-narrow emitter regions, thereby improving emitter efficiency. The same trench process is used to form the emitter/collector trenches as well as the trench isolation structures so that no additional processing steps are needed to form the trench emitter and collector. In embodiments of the present invention, the trench emitter and trench collector regions may be formed using ion implantation into trenches formed in a semiconductor layer. In other embodiments, the trench emitter and trench collector regions may be formed by out-diffusion of dopants from heavily doped polysilicon filled trenches.
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