A memory cell array includes a semiconductor substrate, a first word line formed on the semiconductor substrate, a second word line formed on the semiconductor substrate and extending substantially parallel to the first word line, a first inter-pattern insulating layer interposed between the first and second word lines, first active pillars formed within the first word line and arranged along the first word line at a first interval, and second active pillars formed within the second word lines, and arranged along the second word line to face the first active pillars, respectively, with the first inter-pattern insulating layer interposed therebetween.