The present disclosure provides a semiconductor device, including a substrate structure, a photonic unit, an optical fiber and a chip unit. The substrate structure includes a coupling member. The photonic unit is disposed in a first recess of the coupling member. The optical fiber is disposed in a second recess of the coupling member and optically coupled to the photonic unit. The chip unit is disposed on the substrate structure and electrically connected to the photonic unit through the coupling member. A depth of the second recess is greater than or equal to half a diameter of the optical fiber.