多層堆疊氧化鉿/氧化鋁電阻轉態層之透明電阻式記憶體特性研究

Abstract

我們首開先例的運用原子層沉積法沉積出九循環、十九循環以及三十八循環的氧化鉿及氧化鋁多層堆疊式電阻轉態層，並且運用在透明電阻式記憶體上。其中九循環元件展現出最佳的性能，最多的耐久度，最小的平均操作電壓以及最小的操作電壓標準差，相信是因為三十八循環元件內部過於散佈的氧化鋁導致不易生成穩定傳導絲的緣故。 儘管現今透明電阻式記憶體的性能表現尚無法和非透明電阻式記憶體相提並論，相較於近年透明電阻式記憶體的發展，我們的九循環元件在耐久度、平均操作電壓和操作電壓標準差上已經展現出極佳的性能。根據相關研究指出，氧空缺生成能可因加入鋁而降低，如此有助於生成較為穩定的傳導絲來強化電阻轉態的性能。就我們所知，我們首先應用此一原理於透明電阻式記憶體上來控制傳導絲的生成，不但呼應了前人的研究結果，也將透明電阻式記憶體的性能表現推向更高的水平。將此多層堆疊式電阻轉態層應用在透明電阻式記憶體上，使得透明電阻式記憶體有極大的潛力，來成為新世代未來時尚科技電子產品。

We first demonstrate the resistive switching characteristics of Transparent Resistive Random Access Memory Devices (TRRAM) with HfO2/Al2O3 multi-layer stacking via different ALD deposition cycles as resistive switching films for 9-cycle, 19-cycle and 38-cycle devices respectively. The-9-cycle device has the best performance of endurance times, average set operation voltage, standard deviation of set voltage distribution; average reset operation voltage, standard deviation of reset voltage distribution than the other two (19-cycle and 38-cycle) . For the reason that Al2O3 spread out more in resistive switching layers of the 38-cycle device, it is more difficult to form stable conducting filaments. In addition, our 9-cycle device with endurance times, set/reset operation voltage and standard deviation of reset voltage distribution is relatively excellent compare to recent published transparency memory devices. It was claimed that oxygen vacancy forming energy could be lower down by Al atoms which leads conducting filaments formed more stable in previous non-transparent RRAM. Even though, the performances of TRRAM in this thesis are still not comparable to non-transparent RRAM. To the best of our knowledge, we first apply this mechanism to control the conducting filament formation in TRRAM. Not only echo the previous study of the mechanism but also demonstrate TRRAM with the higher performance. The multi-layer stacking as the resistive switching films in TRRAM shows great potential in the future modern electronics.