摘要
This article reveals that microwave annealing (MWA) is a rapid annealing process, which enhances the compatibility of magnetoresistive random access memory (MRAM) with CMOS in backend processing. It discovers that the magnetic tunnel junction (MTJ) structure is successfully magnetized with hybrid microwave annealing (HMA), confirmed by the tunneling magnetoresistance (TMR) and hysteresis loop. HMA can induce crystallization of CoFeB and promote the formation of Fe-O bonds at the CoFeB/MgO interface. The annealing time is significantly reduced from the original 120 min to just 1 min, allowing for a rapid annealing process of the MTJ structure. The transmission electron microscope (TEM) results are used to determine the change in the lattice structure of CoFeB from amorphous to a single crystal, and the electron energy loss spectrometer (EELS) result indicates the diffusion distribution of atoms in the MTJ structure. This hybrid annealing process can save a significant amount of fabrication time and is an energy-efficient alternative to the furnace annealing process of MRAM.