SRAM memory cell with tri-level local interconnect
A CMOS SRAM cell includes "true" and "false" NMOS word-line access transistors, "true" and "false" NMOS pull-down transistors, and "true" and "false" PMOS pull-down transistors arranged in a classical six-transistor SRAM electrical configuration. "True" and "false" inter-level interconnects of silicidable material provide for respective five-way connections among the transistors. The "true" inter-level interconnect connects: the drain of the "true" pull-up transistor, a gate level polysilicon conductor defining and connecting the gates of the "false" pull-up transistor and the "false" pull-down transistor, and a diffusion region defining and connecting the source of the "true" access transistor and the drain of the "true" pull-down transistor. In a complementary fashion, the "false" inter-level interconnect connects: the drain of the "false" pull-up transistor, a gate level polysilicon conductor defining and connecting the gates of the "true" pull-up transistor and the "true" pull-down transistor, and a diffusion region defining and connecting the drain of the "false" access transistor and the drain of the "false" pull-down transistor. These two five-way connections provide all the necessary local interconnections for the memory cell. The reduced number of inter-level local interconnects required provides for denser memory cell layouts.
VLSI Technology, Inc.
H Y
H01L Y10S
inventional additional
Tiao-Yuan
Huang