Semiconductor device and manufacturing method thereof

The invention discloses a semiconductor device and a manufacturing method thereof, and the method comprises the steps: providing a semiconductor substrate, the semiconductor substrate comprises a first region and a second region which are adjacent, the first region and the second region are respectively provided with a first filling structure and a second filling structure, the semiconductor substrate of the first region is etched, and the semiconductor substrate of the second region is etched; sequentially filling the first groove with a first material and silicon; etching the first filling structure and the second filling structure; respectively forming a first fin structure and a second fin structure; oxidizing the first material; according to the invention, the fin structures of the fin field effect transistor are simultaneously formed in the first region and the second region of the semiconductor substrate with relatively low cost, so that the manufacturing cost is reduced on the basis of simultaneously