Abstract: A magnetoresistive random access memory (MRAM) device includes a first array region and a second array region on a substrate, a first magnetic tunneling junction (MTJ) on the first array region, a first top electrode on the first MTJ, a second MTJ on the second array region, and a second top electrode on the second MTJ. Preferably, the first top electrode and the second top electrode include different nitrogen to titanium (N/Ti) ratios.

Abstract: A magnetoresistive random access memory (MRAM) structure, including a substrate and multiple MRAM cells on the substrate, wherein the MRAM cells are arranged in a memory region adjacent to a logic region. An ultra low-k (ULK) layer covers the MRAM cells, wherein the surface portion of ultra low-k layer is doped with fluorine, and dents are formed on the surface of ultra low-k layer at the boundaries between the memory region and the logic region.

Abstract: A block assembly includes at least two blocks detachably connected with each other. Each of the blocks includes a main body having a bottom provided with a receiving space, at least one connecting knob formed on a top of the main body, a plurality of positioning rails formed on a peripheral wall of the receiving space, and at least one positioning piece located in the receiving space. The positioning piece has a periphery provided with at least four arcuate positioning faces. Thus, when the connecting knob of the first one of the blocks is inserted between the positioning piece and the positioning rails of the second one of the blocks, one of the positioning faces of the positioning piece covers and presses the periphery of the connecting knob of the first one of the blocks.

Abstract: A block assembly includes at least two blocks detachably connected with each other. Each of the blocks includes a main body having a bottom provided with a receiving space, at least one connecting knob formed on a top of the main body, a plurality of positioning rails formed on a peripheral wall of the receiving space, and at least one positioning piece located in the receiving space. The positioning piece has a periphery provided with at least four arcuate positioning faces. Thus, when the connecting knob of the first one of the blocks is inserted between the positioning piece and the positioning rails of the second one of the blocks, one of the positioning faces of the positioning piece covers and presses the periphery of the connecting knob of the first one of the blocks.