Patent ID: 11876123
Assignee: GLOBALFOUNDRIES U.S. INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A method forming a transistor structure, comprising:
providing a substrate;
forming a collector in the substrate;
forming a base on the collector, the base comprising an extrinsic base and an intrinsic base;
forming an emitter on the base;
forming an isolation structure around the emitter, the base, and the collector, the isolation structure containing a dielectric;
forming a trench positioned laterally adjacent to the emitter and the base, wherein the trench extends from above the top of the emitter, through the base, and at least partially into the collector, and wherein the trench undercuts at least a portion of the intrinsic base; and
forming a core connected to the collector, wherein the core comprises a compressive material filing the trench.