Lateral bipolar transistor having buried base contact
 A lateral bipolar transistor comprising a self-aligned polysilicon base contact, and polysilicon emitter and collector contacts is provided. The self-aligned base contact significantly reduces the base width and therefore the base resistance compared with conventional lateral bipolar transistors, thus improving f.sub.t and f.sub.max. The polysilicon emitter and collector contacts improve the emitter efficiency and current gain, and allows for more flexible contact placement. The process is compatible with conventional double-poly bipolar processes. 
Northern Telecom Limited
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inventional inventional inventional
Xiao-Ming Sorin P.
Li Voinigescu