Memory Device: MTJ Etching
MTJ etching is a critical process for MRAM fabrication. The MTJ consists of an complex series of nanoscale metal films and oxide dielectric layers. Applying the techniques of traditional reactive ion etching process will result in non-volatile byproducts. Such non-volatile byproducts will re-deposit on the MTJ sidewalls, making the device non-functional, and affecting device stability. Besides, if the MTJ is exposed in the ambient environment after etching, it will react with the water vapor in the surroundings, resulting in device degradation.