A semiconductor device and a method of manufacturing the same are provided. The semiconductor device includes a semiconductor substrate, a first dielectric layer, a second dielectric layer, a light modulator, a heater, and a first conductive contact. The first dielectric layer is disposed on the semiconductor substrate. The second dielectric layer is disposed on the first dielectric layer. The light modulator is disposed in the first dielectric layer. The heater is disposed in the second dielectric layer and above the light modulator. The first conductive contact is electrically connected to the light modulator. A top surface of the heater is coplanar with a top surface of the first conductive contact.