A semiconductor electronic device structure includes an active area array disposed in a substrate, an isolation structure, a plurality of recessed gate structures, a plurality of word lines, and a plurality of bit lines. The active area array a plurality of active area columns and a plurality of active area rows, defining an array of active areas. The substrate has two recesses formed at the central region thereof. Each recessed gate structure is respectively disposed in the recess. A protruding structure is formed on the substrate in each recess. A STI structure of the isolation structure is arranged between each pair of adjacent active area rows. Word lines are disposed in the substrate, each electrically connecting the gate structures there-under. Bit lines are disposed above the active areas, forming a crossing pattern with the word lines.