A semiconductor device includes an integrated circuit (IC) and an interlayer dielectric layer on the substrate, a contact through the interlayer dielectric layer and electrically connected to the IC, a wiring layer on the interlayer dielectric layer with a wiring line electrically connected to the contact, a first passivation layer on the wiring layer, first and second pads on the first passivation layer, and a through electrode through the substrate, the interlayer dielectric layer, the wiring layer, and the first passivation layer to connect to the first pad. The first pad includes a first head part on the first passivation layer, and a protruding part that extends into the first passivation layer from the first head part, the protruding part surrounding a lateral surface of the through electrode in the first passivation layer, and the second pad is connected to the IC through the wiring line and the contact.