Forming Fe nanocrystals by reduction of ferritin nanocores for metal nanocrystal memory
Forming Fe nanocrystals by reduction of ferritin nanocores for metal nanocrystal memory
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DOI：
10.1063/5.0092210
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发表时间：
2022-05
期刊：
影响因子：
1.6
通讯作者：
T. Matsumura;A. Miura;Takio Hikono;Y. Uraoka
中科院分区：
文献类型：
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作者：
T. Matsumura;A. Miura;Takio Hikono;Y. Uraoka
为了制备基于铁蛋白的金属纳米晶(NC)存储器，我们提出了一种在二氧化硅中嵌入铁蛋白核心并在氢气气氛中进行快速热退火(RTA)还原工艺的方法。利用铁蛋白生物合成的氧化铁芯制备了7.7×1011点/cm2的高密度存储节点阵列。在氢气气氛下，氧化铁核包埋在二氧化硅中，可在短时间内得到还原中间体和金属铁纳米碳化物。制备了金属-氧化物-半导体存储结构，进行了电容-电压(C-V)测量，观察到了NCS充放电的滞后现象(存储窗口)。此外，记忆窗口和电荷注入阈值往往随还原温度的不同而变化。由于这些值与点功函数(或电子亲和力)的大小成正比，因此假设还原的中间体NCS的形成取决于处理温度而具有不同的功函数，从而影响电学性质。结果表明，电荷保持节点的功函数可以通过还原金属氧化物来控制，这使得一种积极采用还原过程的存储器设计成为可能。
To fabricate metal nanocrystal (NC) memories based on iron ferritin proteins, we propose a method for embedding ferritin cores in SiO2 and performing a reduction process by rapid thermal annealing (RTA) in a hydrogen atmosphere. An iron oxide core biochemically synthesized by ferritin was used to fabricate a high-density memory node array of 7.7 × 1011 dots/cm2. Reduction intermediates and metallic iron NCs were obtained in a short time by using a hydrogen atmosphere RTA with the iron oxide core embedded in SiO2. Metal-oxide-semiconductor memory structures were fabricated, capacitance–voltage (C–V) measurements were performed, and hysteresis (memory window) suggesting charging and discharging of NCs was observed. Furthermore, the memory window and the charge injection threshold tended to vary depending on the reduction temperature. Since these values are proportional to the magnitude of the dot work function (or electron affinity), it is assumed that the formation of reduced intermediates NCs with varying work functions depending on the treatment temperature affects the electrical properties. The results suggest that the work function of the charge retention node can be controlled by reducing the metal oxide, enabling a new approach to memory design that actively employs the reduction process.