Semiconductor device and method for forming the same

A semiconductor device, comprising:

• a substrate having a logic region and a memory region;
• a first interlayer dielectric layer disposed on the substrate;
• a second interlayer dielectric layer disposed on the first interlayer dielectric layer and directly contacts a top surface of the first interlayer dielectric layer, wherein a portion of the top surface of the first interlayer dielectric layer on the memory region is lower than another portion of the top surface of the first interlayer dielectric layer on the logic region;
• a memory stack structure disposed in the first interlayer dielectric layer on the memory region;
• a passivation layer covering a top surface and sidewalls of the memory stack structure, wherein the second interlayer dielectric layer directly contacts the passivation layer;
• and
• an upper contact structure through the second interlayer dielectric layer and the passivation layer on the top surface of the memory stack structure and directly contacting the memory stack structure.