Patent ID: 11864368
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A static random access memory (SRAM) cell comprising:
a first semiconductor fin and a fourth semiconductor fin extending along a first direction over a first p-well;
a first gate structure extending along a second direction perpendicular to the first direction, the first gate structure forming a first write-port pull-down transistor with the first semiconductor fin and a read-port pull-down transistor with the fourth semiconductor fin,
wherein the first gate structure has a continuous work function metal spanning the first write-port pull-down transistor and the read-port pull-down transistor;
a third semiconductor fin extending along the first direction over a second p-well spaced from the first p-well;
a second gate structure extending along the second direction and forming a second write-port pull-down transistor with the third semiconductor fin, wherein a channel region of the second write-port pull-down transistor has a p-type doping concentration lower than a p-type doping concentration of a channel region of the first write-port pull-down transistor and higher than a p-type doping concentration of a channel region of the read-port pull-down transistor; and
a fourth gate structure forming a first write-port pass-gate transistor with the first semiconductor fin, wherein a channel region of the first write-port pass-gate transistor has a p-type doping concentration lower than the p-type doping concentration of the channel region of the first write-port pull-down transistor.