First, a device wafer having a substrate layer and a device layer is provided. Then, a first mask pattern is utilized to remove the device layer uncovered by the first mask pattern. Subsequently, a medium layer is formed on the surface of the device wafer, and the medium layer is then bonded to a carrier wafer. Thereafter, a second mask pattern is utilized to remove the substrate layer uncovered by the second mask pattern. Finally, the medium layer is separated from the carrier wafer, the substrate layer is bonded to an extendable film, and the medium layer is then removed.