Lateral bipolar transistor
AssigneeMotorola, Inc.
InventorLalgudi M. G. Sundaram
Life of this patent
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Abstract
A lateral bipolar transistor structure (10) formed in a laterally isolated semiconductor device tub (22) of a first conductivity type is provided. First and second trenches are etched in the device tub and filled with doped polysilicon of a second conductivity type to form an emitter (30) and a collector (32). The portion of the tub (22) between the emitter (30) and collector (32) regions forms a base region. This configuration provides high emitter area and minimal device surface area, as well as emitter (30) and collector (32) regions which are interchangeable, greatly easing layout of integrated circuits using the transistor structure (10).
Claims10
A lateral bipolar transistor structure comprising:
- a laterally isolated semiconductor tub of a first conductivity type;
- a first trench etched in the device tub, wherein the first trench is filled with polysilicon of a second conductivity type to form an emitter region;
- a second trench etched in the device tub, wherein the second trench is filled with polysilicon of the second conductivity type to form a collector region;
- and
- a base region of the first conductivity type comprising the tub between the emitter and collector regions.
A lateral bipolar transistor structure comprising:
- a laterally isolated semiconductor device tub of a first conductivity type;
- an emitter formed by etching a first trench into the device tub and filling the first trench with polycrystalline semiconductor doped in a second conductivity type;
- a collector formed by etching a second trench into the device tub and filling the second trench with polycrystalline semiconductor doped in a second conductivity type;
- a base region of the first conductivity type between the emitter and collector;
- a polycrystalline semiconductor plug doped in the first conductivity type disposed above the device tub between the first and second trenches;
- an emitter electrode coupled to the emitter;
- a collector electrode coupled to the collector;
- and
- a base electrode coupled to the polycrystalline semiconductor plug.
Dependencies are inferred from the claim text.