Semiconductor devices

A semiconductor device includes a capacitor. The capacitor includes a bottom electrode, a dielectric layer, and a top electrode that are sequentially stacked in a first direction. The dielectric layer includes a first dielectric layer and a second dielectric layer that are interposed between the bottom electrode and the top electrode and are stacked in the first direction. The first dielectric layer is anti-ferroelectric, and the second dielectric layer is ferroelectric. A thermal expansion coefficient of the first dielectric layer is greater than a thermal expansion coefficient of the second dielectric layer.