Static random access memory cell having pocket regions adjacent to sources of drive transistors

Claim 1

A static random access memory cell including two cross-coupled drive MOS transistors and two transfer MOS transistors connected to said drive MOS transistors, comprising: a semiconductor substrate of a first conductivity type; a plurality of gate electrodes of said drive MOS transistors and said transfer MOS transistors, formed over said semiconductor substrate; a plurality of first impurity diffusion regions of a second conductivity type opposite to said first conductivity type, formed within said semiconductor substrate, each of said first impurity regions forming one of drains and sources of said drive MOS transistors and said transfer MOS transistors; a plurality of pocket regions of said first conductivity type formed within said semiconductor substrate, each of said pocket regions being adjacent to substantially only the sides of the sources of said drive MOS transistors and immediately beneath the gate electrodes of said drive MOS transistors, and an impurity concentration of said pocket regions being larger than an impurity concentration of said semiconductor substrate.