SBIR Phase I: Enhanced Plasma deposition Process for MgO-Based Magnetic Tunnel Junctions with 500% Magnetoresistance

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This Small Business Innovation Research (SBIR) Phase I project aims to demonstrate thefeasibility of fabricating high quality MgO-based magnetic tunnel junction (MTJ) deviceswith magnetoresistance (MR) values of over 500%, via an innovative process whichutilizes optimized plasma-based magnetron sputtering and RF plasma oxidation. We willuse a number of novel methods to fabricate highly symmetrical, near epitaxial MgObarriers with (001)-orientation using plasma sputtering and oxidation methods. Usingthese methods, we will be able to realize a smoother barrier and the resulting process willbe suitable for adaptation to large-scale production with high yield and uniformity. Ourmethod combines three innovations. First, we will design a new deposition procedure tomake symmetrical interfaces on both sides of the MgO barrier to enhance the coherenttunneling effect required for high MR. Secondly, we will improve the (001) texture of theMgO barrier by choosing ferromagnetic layers with a composition tuned for both highspin polarization and small lattice mismatch. Finally, we will implement a new plasmaoxidation method to minimize both plasma damage to the barrier and MTJ interfaceroughness. If successful, the resulting MgO-based MTJ devices will surpass theperformance of all other existing magnetoresistive devices.Commercially, this technology will have a huge commercial impact on the non-volatile memory specifically, for MRAM (magnetic random access memory) and disk drive for tunnel magnetoresistance (TMR) read/write heads industries. The success of the project will not only bolster the market position of MRAM and MTJ read heads, but will also enable innovative new products in other market segments, such as semiconductor failureanalysis and a wide range of emerging bio-magnetic applications.