Improvement of Current Induced Magnetization Switching Devices for Ultra-High Density Magnetoresistive Random Access Memory

Abstract

The current induced magnetization switching effect at room temperature in various type of structure has been systematically investigated. We report that the effect can be enhanced by an insertion of a copper layer between the free cobalt and the gold capping layer, by the deposition of a ruthenium layer onto a substrate as a buffer layer, by the use of an exchange biased spin valve structure, and by a formation of a nano oxide layer in the middle of a thick cobalt pinned layer. The critical switching current of the nano-sized junction device measures as small as 7.5x10(6) A/cm(2) and the magnetoresistance as large as 2.5% even in an exchange biased spin valve structure.