A method for fabricating semiconductor device includes the steps of: providing a substrate having a logic region and a magnetoresistive random access memory (MRAM) region, forming a magnetic tunneling junction (MTJ) on the MRAM region, forming a metal interconnection on the MTJ, forming a dielectric layer on the metal interconnection, patterning the dielectric layer to form openings, and forming the blocking layer on the patterned dielectric layer and the metal interconnection and into the openings.