Three-dimensional (3D) semiconductor devices and fabricating methods are provided. In some implementations, a 3D semiconductor device includes: an array of vertical transistors each comprising a semiconductor body extending in a vertical direction; a plurality of word lines each extending in a first lateral direction, wherein each word line is shared by a row of the vertical transistors arranged along the first lateral direction; and a plurality of bit lines each extending in a second lateral direction perpendicular to the first lateral direction; wherein the semiconductor bodies are further arranged along a third lateral direction different from the first lateral direction and the second lateral direction.