SEMICONDUCTOR MEMORY DEVICE AND METHOD OF FABRICATING THE SAME

A semiconductor memory device includes a static random access memory (SRAM) cell that is provided on a substrate and includes a pass-gate transistor, a pull-down transistor, and a pull-up transistor. Each of the pass-gate transistor, the pull-down transistor, and the pull-up transistor includes an active fin protruding above a device isolation layer, a gate electrode on the active fin, and a gate insulating layer between the active fin and the gate electrode. The gate insulating layer of the pull-down transistor includes a first dipole element. The highest concentration of the first dipole element of the gate insulating layer of the pull-down transistor is higher than the highest concentration of the first dipole element of the gate insulating layer of the pass-gate transistor.