A showerhead is configured to be mounted inside a processing chamber and provide a processing gas onto a semiconductor wafer inside the processing chamber. The showerhead includes a supply plenum, a faceplate, and an electrode plate assembly. The faceplate is disposed at a side of the supply plenum. The electrode plate assembly is disposed between a gas source and the supply plenum. The electrode plate assembly includes a first plate having a unitary construction and having a plurality of first gas holes, and a second plate having a unitary construction and having a plurality of second gas holes. The second plate is located between the first plate and the supply plenum and separated from the first plate. The plurality of second gas holes are partially overlapped but misaligned with the plurality of first gas holes. A semiconductor apparatus having the same and a semiconductor process are also provided.