International Business Machines Corporation
MRAM device formation with controlled ion beam etch of MTJ

Abstract:

Controlled IBE techniques for MRAM stack patterning are provided. In one aspect, a method of forming an MRAM device includes: patterning an MRAM stack disposed on a dielectric into individual memory cells using IBE landing on the dielectric while dynamically adjusting an etch time to compensate for variations in a thickness of the MRAM stack, wherein each of the memory cells includes a bottom electrode, an MTJ, and a top electrode; removing foot flares from the bottom electrode of the memory cells which are created during the patterning of the MRAM stack; removing residue from sidewalls of the memory cells which includes metal redeposited during the patterning of the MRAM stack and during the removing of the foot flares; and covering the memory cells in a dielectric encapsulant. An MRAM device is also provided.