Semiconductor device and method of fabricating the same

A semiconductor device, comprising;

• a substrate comprising a shallow trench isolation and an active structure defined by the shallow trench isolation, the active structure comprising:
• a first active area comprising a plurality of active area units being parallel extended along a first direction;
• and
• a second active area disposed outside a periphery of the first active area, to surround all of the active area units;
• and
• a plurality of word lines, disposed in the substrate, extending in a second direction to intersect with the active area units and the shallow trench isolation, wherein the word lines comprises a plurality of first word lines and a plurality of second word lines, the first word lines are sequentially arranged along a third direction perpendicular to the second direction by a first pitch, the second word lines are sequentially arranged along the third direction by a second pitch, and the second pitch is greater than the first pitch.