Provided are a deposition method, a semiconductor device and a method of fabricating the same. The semiconductor device includes a substrate and a dielectric structure. The substrate includes at least one fin thereon. The dielectric structure covers the at least one fin. A thickness of the dielectric structure located on a top surface of the at least one fin is greater than a thickness of the dielectric structure located on a sidewall of the at least one fin. The dielectric structure includes a first dielectric layer and a second dielectric layer. The first dielectric layer is conformally disposed on the at least one fin. The second dielectric layer is disposed on the first dielectric layer over the top surface of the at least one fin. A thickness of the second dielectric layer is greater than a thickness of the first dielectric layer.