Eight-transistor static random access memory, layout thereof, and method for manufacturing the same

A Static Random Access Memory (SRAM) cell includes a write port including a first inverter including a first pull-up transistor and a first pull-down transistor, and a second inverter including a second pull-up transistor and a second pull-down transistor and cross-coupled with the first inverter; and a read port including a read pass-gate transistor and a read pull-down transistor serially connected to each. A first doped concentration of impurities doped in channel regions of the second pull-down transistor and the read pull-down transistor is greater than a second doped concentration of the impurities doped in a channel region of the first pull-down transistor, or the impurities are doped in the channel regions of the second pull-down transistor and the read pull-down transistor and are not doped in the channel region of the first pull-down transistor.