A method for fabricating a semiconductor device includes the steps of forming a metal-oxide semiconductor (MOS) transistor on a substrate, forming an interlayer dielectric (ILD) layer on the MOS transistor, forming a ferroelectric field effect transistor (FeFET) on the ILD layer, and forming a ferroelectric random access memory (FeRAM) on the ILD layer. The formation of the FeFET further includes first forming a semiconductor layer on the ILD layer, forming a gate structure on the semiconductor layer, and then forming a source/drain region adjacent to the gate structure.