A magnetic tunneling junction device and fabrication method is disclosed. In a particular embodiment, a non-transitory computer-readable medium includes processor executable instructions. The instructions, when executed by a processor, cause the processor to initiate deposition of a capping material on a free layer of a magnetic tunneling junction structure to form a capping layer. The instructions, when executed by the processor, cause the processor to initiate oxidization of a first layer of the capping material to form a first oxidized layer of oxidized material.