Domain wall-magnetic tunnel junction spin-orbit torque devices and circuits for in-memory computing
Domain wall-magnetic tunnel junction spin-orbit torque devices and circuits for in-memory computing
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DOI：
10.1063/5.0038521
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发表时间：
2021-03-15
影响因子：
4
通讯作者：
Incorvia, Jean Anne C.
中科院分区：
文献类型：
--
作者：
Alamdar, Mahshid;Leonard, Thomas;Incorvia, Jean Anne C.
传统计算存在紧迫的问题，特别是在完成数据密集型和实时任务方面，这促使内存计算设备的发展来存储信息和执行计算。磁性隧道结存储元件可通过操纵畴壁（磁畴之间的过渡区域）来进行计算，但此类器件的实验研究受到高电流密度和低隧道磁阻的限制。在这里，我们研究了三端畴壁磁隧道结内存计算器件的原型，该器件可以解决数据处理瓶颈，并通过使用垂直磁各向异性、自旋轨道扭矩切换和优化光刻工艺来解决这些挑战，产生平均器件隧道磁阻TMR = 171％和平均电阻面积乘积RA = 29Omegamu m2，接近未图案化薄膜的RA。通过控制畴壁初始位置，开关电压的器件初始化变化被减少到 7%-10%，我们表明这对应于畴壁-磁隧道结全加器模拟中的 90%-96% 精度。显示了写入和重置设备的可重复性。电路显示了两个器件之间的逆变器操作，表明与变化噪声相比，电压窗口足够大，可以重复操作畴壁磁隧道结电路。这些结果在将磁隧道结和磁畴壁用于内存和神经形态计算应用方面取得了长足的进步。
There are pressing problems with traditional computing, especially for accomplishing data-intensive and real-time tasks, that motivate the development of in-memory computing devices to both store information and perform computation. Magnetic tunnel junction memory elements can be used for computation by manipulating a domain wall, a transition region between magnetic domains, but the experimental study of such devices has been limited by high current densities and low tunnel magnetoresistance. Here, we study prototypes of three-terminal domain wall-magnetic tunnel junction in-memory computing devices that can address data processing bottlenecks and resolve these challenges by using perpendicular magnetic anisotropy, spin-orbit torque switching, and an optimized lithography process to produce average device tunnel magnetoresistance TMR=171% and average resistance-area product RA=29Omegamu m2, close to the RA of the unpatterned film. Device initialization variation in switching voltage is shown to be curtailed to 7%-10% by controlling the domain wall initial position, which we show corresponds to 90%-96% accuracy in a domain wall-magnetic tunnel junction full adder simulation. Repeatability of writing and resetting the device is shown. A circuit shows an inverter operation between two devices, showing that a voltage window is large enough, compared to the variation noise, to repeatably operate a domain wall-magnetic tunnel junction circuit. These results make strides in using magnetic tunnel junctions and domain walls for in-memory and neuromorphic computing applications.