Patent ID: 11881395
Assignee: GLOBALFOUNDRIES U.S. INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. A bipolar transistor structure comprising:
a triple well stack, including:
a deep well region,
a substrate portion over the deep well region, and
a doped semiconductor layer over the substrate portion and coupled to a base contact, wherein the deep well region has a same doping type as the doped semiconductor layer;

a first semiconductor fin on the doped semiconductor layer of the triple well stack, the first semiconductor fin including:
a lower portion on the doped semiconductor layer, the lower portion having a first dopant concentration, and
an upper portion on the lower portion, the upper portion having a second dopant concentration that is less than the first dopant concentration;

an emitter/collector (E/C) material on a sidewall of the upper portion of the first semiconductor fin, wherein a lateral width of the E/C material from an outside surface of the E/C material to the sidewall of the first semiconductor fin is greater than a lateral width of the first semiconductor fin;
an E/C contact on the E/C material;
a second semiconductor fin on the doped semiconductor layer of the triple well stack, wherein the second semiconductor fin has a same doping type as the doped semiconductor layer; and
a base contact on the second semiconductor fin, wherein the second semiconductor fin extends vertically continuously from the doped semiconductor layer of the triple well stack to the base contact, and an upper surface of the second semiconductor fin physically contacts a lower surface of the base contact.