a semiconductor substrate;

first and second local recess channel transistors, each comprising:

source/drain regions in the substrate;

a recess trench in the substrate between adjacent source/regions;

a gate in the recess trench and extending between a lower portion of the trench and an upper surface of the substrate; and

a local channel impurity doped region in the substrate below and surrounding lower side portions of the gate in the lower portion of the recess trench, wherein a common one of the source/drain regions extends between the gates of the first and second local recess channel transistors, the common one of the source/drain regions is doped with a different conductive type impurity than the local channel impurity doped regions, the local channel impurity doped region of the first local recess channel transistor is isolated from the local channel impurity doped region of the second local recess channel transistor, and the common one of the source/drain regions overlies a portion of the substrate that isolates the local channel impurity doped regions of the first and second local recess channel transistors.