According to an embodiment of the present invention, the MTJ structure 20b is a dummy MTJ structure. The high-density MRAM device 1 further includes a local interconnect structure 50 disposed on the dummy MTJ structure 20b. The local interconnect structure 50 includes a metal layer 501 located on the dummy MTJ structure 20b and a via layer 502 electrically connecting the metal layer 501 to the metal pad 110b. The dummy MTJ structure 20b includes an upper electrode 201b and a lower electrode 202b. The upper electrode 201b is in direct contact with the metal layer 501, and the lower electrode 202b is not directly connected with the metal pad 110b.

According to an embodiment of the present invention, the high-density MRAM device 1 further includes an interconnection structure 70 electrically connected to the metal pad 110c. The interconnection structure 70 penetrates through the ILD layer L4, the ILD layer L2 and the capping layer CL. According to an embodiment of the present invention, the metal pad 110c is a word line strap.

According to an embodiment of the present invention, the ILD layer L1 and the ILD layer L4 are ultra-low dielectric constant (ULK) layers. According to an embodiment of the present invention, the ILD layer L2 and the ILD layer L3 are silicon oxide layers.