Semiconductor memory devices including offset active regions

A semiconductor memory device comprising:

• a substrate including a plurality of active regions wherein each of the plurality of active regions has a length in a direction of a first axis and a width in a direction of a second axis, wherein the length is greater than the width, wherein the plurality of active regions are provided in a plurality of columns of active regions in the direction of the second axis, and wherein active regions of adjacent columns are offset in the direction of the second axis;
• a field isolation layer on the substrate surrounding the active regions of the substrate;
• a plurality of pairs of wordlines on the substrate wherein each pair of wordlines crosses active regions of a respective column of active regions, wherein each pair of wordlines defines first and second source portions of each active region of the respective column on opposite sides of the pair of wordlines and a drain portion of each active region of the column between the pair of wordlines;
• and
• a plurality of bit lines on the substrate, wherein each of the plurality of bitlines crosses the plurality of pairs of wordlines and wherein each bitline is coupled to a drain portion of a respective active region of each column of active regions;
• and
• a drain pad electrically coupled between one of the bitlines and a drain portion of a respective one of the active regions wherein a portion of the drain pad is between the bitline and the field isolation layer in a direction perpendicular to the substrate wherein the drain pad extends on the field isolation layer in a first direction perpendicular to the active region on a first side of the active region further than the drain pad extends in a second direction on a second side of the active region wherein the first and second directions are opposite directions.