A semiconductor device including a substrate that has a first region and a second region, a plurality of lower conductive patterns on the substrate, the plurality of lower conductive patterns including a first conductive pattern in the first region of the substrate and a second conductive pattern in the second region of the substrate, a magnetic tunnel junction on the first conductive pattern, a contact between the magnetic tunnel junction and the first conductive pattern, a through electrode on the second conductive pattern, and a plurality of upper conductive patterns on the magnetic tunnel junction and the through electrode. The contact includes a first contact on the lower conductive patterns, a second contact on the first contact, and a first barrier layer that covers a bottom surface and a lateral surface of the second contact.