Hwang Yeong-Hyeon, Hwang Inchan, Cho Won-Ju
J Nanosci Nanotechnol. 2014 Nov;14(11):8196-200. doi: 10.1166/jnn.2014.9892.
The influence of composition ratio on the bipolar resistive switching behavior of resistive switching memory devices based on amorphous indium-gallium-zinc-oxide (a-IGZO) using the spin-coating process was investigated. To study the stoichiometric effects of the a-IGZO films on device characteristics, four devices with In/Ga/Zn stoichiometries of 1:1:1, 3:1:1, 1:3:1, and 1:1:3 were fabricated and characterized. The 3:1:1 film showed an ohmic behavior and the 1:1:3 film showed a rectifying switching behavior. The current-voltage characteristics of the a-IGZO films with stoichiometries of 1:1:1 and 1:3:1, however, showed a bipolar resistive memory switching behavior. We found that the three-fold increase in the gallium content ratio reduces the reset voltage from -0.9 to - 0.4 V and enhances the current ratio of high to low resistive states from 0.7 x 10(1) to 3 x 10(1). Our results show that the increase in the Ga composition ratio in the a-IGZO-based ReRAM cells effectively improves the device performance and reliability by increasing the initial defect density in the a-IGZO films.
研究了通过旋涂工艺制备的基于非晶铟镓锌氧化物（a-IGZO）的电阻式开关存储器器件中，成分比例对其双极电阻开关行为的影响。为了研究a-IGZO薄膜的化学计量比效应，制备并表征了四种铟/镓/锌化学计量比分别为1:1:1、3:1:1、1:3:1和1:1:3的器件。3:1:1的薄膜表现出欧姆行为，1:1:3的薄膜表现出整流开关行为。然而，化学计量比为1:1:1和1:3:1的a-IGZO薄膜的电流-电压特性表现出双极电阻式存储器开关行为。我们发现，镓含量比例增加三倍会使复位电压从-0.9 V降低到-0.4 V，并将高阻态与低阻态的电流比从0.7×10¹提高到3×10¹。我们的结果表明，基于a-IGZO的阻变随机存取存储器（ReRAM）单元中Ga成分比例的增加，通过提高a-IGZO薄膜中的初始缺陷密度，有效地改善了器件性能和可靠性。
