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

这个小企业创新研究（SBIR）第一阶段项目旨在通过利用优化的基于等离子体的磁控溅射和射频等离子体氧化的创新工艺，证明制造高质量磁电阻（MR）值超过500%的基于氧化镁的磁隧道结（MTJ）器件的可行性。我们将使用许多新方法来制造高度对称的、近外延的（001）取向的mgo势垒，使用等离子溅射和氧化方法。使用这些方法，我们将能够实现更平滑的屏障，所得到的工艺将适合适应大规模生产，具有高收率和均匀性。我们的方法结合了三个创新。首先，我们将设计一种新的沉积工艺，在MgO势垒两侧制作对称界面，以增强高mr所需的相干隧道效应。其次，我们将通过选择具有高自旋极化和小晶格失配的铁磁层来改善MgO势垒的（001）织构。最后，我们将实现一种新的等离子体氧化方法，以最大限度地减少等离子体对屏障和MTJ界面的损伤。如果成功，由此产生的基于mgo的MTJ器件将超过所有其他现有的磁阻器件的性能。在商业上，这项技术将对非易失性存储器产生巨大的商业影响，特别是对MRAM（磁性随机存取存储器）和隧道磁阻（TMR）读/写磁头行业的磁盘驱动器。该项目的成功不仅将巩固MRAM和MTJ读头的市场地位，而且还将使其他细分市场的创新产品成为可能，例如半导体故障分析和广泛的新兴生物磁性应用。

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.