US Patent 7869262 Memory device with an asymmetric layout structure

An SRAM device includes a first inverter; a second inverter cross-coupled with the first inverter; a first pass gate transistor connecting the first inverter to a bit line; and a second pass gate transistor connecting the second inverter to a complementary bit line, wherein the first or second pass gate transistor has a layout structure where a first distance between its gate conductive layer and its source contact is purposefully designed to be substantially different from a second distance between its gate conductive layer and its drain contact for reducing leakage current induced by misalignment of the gate conductive layer with respect to the source contact.