Patent ID: 7778059

Claim:
A phase change memory device comprising: a semiconductor substrate having a plurality of active regions, each of which extending in one direction, and the plurality of active regions being arranged in another direction; a plurality of word lines formed on the active regions to extend in another direction; a plurality of bit lines arranged to extend in one direction that is perpendicular to the word lines; and sense amplifiers connected with the bit lines, wherein the sense amplifiers include a first sense amplifier and a second sense amplifier placed adjacent a first end of the active regions and a second end of the active regions opposite the first end, respectively, wherein the bit lines include first bit lines which are connected with the first sense amplifier and second bit lines which are connected with the second sense amplifier, wherein the first and second bit lines are alternately arranged with each other, and wherein each of the active regions include a first active region and a second active region, the first active region has a first area having a first width, a second area having a second width greater than the first width, and a third area having a third width greater than the second width, which are sequentially arranged in a direction extending toward the first sense amplifier, and the second active region has a first area having a first width, a second area having a second width greater than the first width, and a third area having a third width greater than the second width, which are sequentially arranged in a direction extending toward the second sense amplifier.