Bipolar junction transistor incorporating integral field plate
AssigneeLegerity, Inc.
InventorsFrank L. Thiel, William E. Moore, Philip S. Shiota
Life of this patent
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Abstract
A semiconductor process is disclosed which forms a field plate structure that integrally contacts an emitter region of a bipolar junction transistor by construction, without intervening interconnect layers or contacts. In one embodiment, a single-layer polysilicon electrode forms a field plate electrode which integrally interconnects to a traditional diffused emitter region formed before the polysilicon layer is deposited. This allows for deeper emitter regions required by the deep base regions needed for high-voltage bipolar devices. Moreover, the polysilicon layer, including the polysilicon electrode forming the field plate electrode, may be used as a local interconnect layer.
Claims16
A bipolar junction transistor structure comprising:
- a collector region, a base region, and an emitter region formed within a semiconductor body, said collector and base regions defining therebetween a collector/base junction intersecting a top surface of the semiconductor body;
- a single-layer conductive electrode which contacts the emitter region and which is vertically aligned with and which lies directly above the collector/base junction at its intersection with the top surface, said conductive electrode extending at least a predetermined distance in a direction toward and disposed over the collector region and also extending at least a predetermined distance in a direction toward and disposed over the base region, thereby forming an integral field plate structure and emitter region contact;
- and
- an interconnect element contacted to the conductive electrode to provide an electrical connection to the emitter region and to the field plate structure.
A structure as in claim wherein:
- the single-layer conductive electrode comprises a polysilicon electrode.
A bipolar junction transistor structure comprising:
- a collector region formed within a semiconductor body having, where the collector region reaches a top surface of the semiconductor body, a first dielectric layer thereabove;
- a base region formed within the collector region having, where the base region reaches the top surface of the semiconductor body, a second dielectric layer thereabove, said collector and base regions defining therebetween a collector/base junction intersecting the top surface of the semiconductor body;
- an emitter region formed within the base region;
- a polysilicon electrode disposed above and contacting the emitter region, and further disposed directly above and vertically aligned with the intersection of the collector/base junction with the top surface of the semiconductor body, said conductive electrode extending at least a predetermined distance in a direction toward and disposed over the collector region and also extending at least a predetermined distance in a direction toward and disposed over the base region, whereby the conductive electrode forms an integral field plate structure and emitter region contact;
- and
- an interconnect element contacted to the conductive electrode for providing an electrical connection to the emitter region and for biasing the field plate structure with the emitter region voltage.
Dependencies are inferred from the claim text.