Provided is a semiconductor device. The semiconductor device includes a passivation layer defining a metal pattern on a first surface of a substrate, an inter-layer insulating layer disposed on a second surface of the substrate, and a piezoelectric pattern formed between the metal pattern and the passivation layer on the first surface of the substrate. A through-silicon-via and/or a pad can be directly bonded to another through-silicon-via and/or another pad by applying pressure only, and without performing a heat process.