A semiconductor device includes a substrate having an array region defined thereon, a ring of magnetic tunneling junction (MTJ) region surrounding the array region, a gap between the array region and the ring of MTJ region, and metal interconnect patterns overlapping part of the ring of MTJ region. Preferably, the ring of MTJ region comprises an octagon and the ring of MTJ region includes a first MTJ region and a second MTJ region extending along a first direction, a third MTJ region and a fourth MTJ region extending along a second direction, a fifth MTJ region and a sixth MTJ region extending along a third direction, and a seventh MTJ region and an eighth MTJ region extending along a fourth direction.