Bipolar transistor structures with cavity below extrinsic base and methods to form same
AssigneeGlobalFoundries U.S. Inc.
InventorsUppili S. Raghunathan, Alexander M. Derrickson, Sarah A. McTaggart, Judson Robert Holt, Vibhor Jain
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Abstract
The disclosure provides bipolar transistor structures with a cavity below an extrinsic base, and methods to form the same. A structure of the disclosure provides a bipolar transistor structure including an extrinsic base protruding from an intrinsic base of a bipolar transistor. The extrinsic base extends over a cavity. An insulator is horizontally adjacent the cavity and below a portion of the extrinsic base. A collector extension region of the bipolar transistor structure extends laterally below the insulator and the cavity.
Claims20
A structure comprising:
- a bipolar transistor structure including an extrinsic base protruding from an intrinsic base of the bipolar transistor structure, wherein an upper surface of the extrinsic base includes a notch;
- an insulator below a portion of the extrinsic base, wherein a collector extension region of the bipolar transistor structure extends laterally below the insulator;
- and
- a cavity encapsulated within the insulator, wherein the cavity is vertically between the collector extension region and the portion of the extrinsic base, and horizontally offset from the notch.
A structure comprising:
- a vertical bipolar transistor structure including:
- a collector on a substrate,
- an intrinsic base on the collector,
- an extrinsic base protruding from the intrinsic base,
- wherein an upper surface of the extrinsic base includes a notch, and
- an emitter on a portion of the intrinsic base;
- an insulator below a portion of the extrinsic base, wherein a collector extension region of the bipolar transistor structure extends laterally below the insulator;
- and
- a cavity encapsulated within the insulator, wherein the cavity is vertically between the collector extension region and the portion of the extrinsic base, and horizontally offset from the notch.
A method comprising:
- forming a bipolar transistor structure including an extrinsic base protruding from an intrinsic base of the bipolar transistor structure, wherein an upper surface of the extrinsic base includes a notch;
- forming an insulator and below a portion of the extrinsic base, wherein a collector extension region of the bipolar transistor structure extends laterally below the insulator;
- and
- forming a cavity encapsulated within the insulator, wherein the cavity is vertically between the collector extension region and the portion of the extrinsic base, and horizontally offset from the notch.
Dependencies are inferred from the claim text.