US Patent 8680605 Stacked memory devices and method of manufacturing the same

A stacked memory device may include at least one memory unit and at least one peripheral circuit unit arranged either above or below the at least one memory unit. The at least one memory unit may include a memory string array, a plurality of bit lines, and a plurality of string selection pads. The memory string may include a plurality of memory strings arranged in a matrix and each of the memory strings may include a plurality of memory cells and a string selection device arranged perpendicular to a substrate. The plurality of bit lines may extend in a first direction and may be connected to ends of the plurality of memory strings. The plurality of string selection pads may be arrayed in a single line along the first direction and may be connected to the string selection devices included in the plurality of memory strings.