In this paper,a CMOS compatible integration strategy for film bulk acoustic wave resonator (FBAR) post-CMOS integration is proposed.By choosing amorphous silicon deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) method as the sacrificial layer and low temperature isotropic plasma dry etching as the releasing process,we could manufacture the FBAR device directly on the passivation layer of the CMOS integrated circuits (CMOS IC) chips.Compared with the reported strategies,this strategy features simple fabrication process and low thermal budget which ensures a minor influence on the fabricated CMOS IC.The manufactured FBAR exhibils well performed resonant characteristics at 2.4GHz.The co-design of the FBAR and the oscillator based on UMC 0.18tm CMOS process and the simulation results has been demonstrated.