氧化鉿電阻式記憶體搭配可撓式氧化物選擇器

HfOx-based resistive random access memory with oxide-based flexible selector

洪誌廷(Zhi-Ting Hung)

指導教授 ： 曾俊元

國立交通大學/電機學院/電子工程系所/碩士(2018年)

摘要

電阻式隨機存取記憶被視為最有潛力的非揮發性記憶體，因為其具備低功耗、高操作速度和可做成三維結構……等優點。然而，當電阻式記憶體做成記憶體陣列後會面臨一個問題，蛇型漏電流。蛇型漏電流會導致記憶體陣列讀取錯誤和消耗額外功率等問題。選擇器被視為其中一個解決方法，選擇器和電阻式記憶體串聯後，可有效限制漏電流的產生。
在本文中，利用濺鍍系統沉積各種氧化物組成選擇器的中間層，並沉積氮化鉭做為電極。首先，一開始是以單層氧化鉭做為中間層，並調變厚度來改變電性。之後加入不同氧化層提高選擇比，同時改變氧化層厚度探討厚度和電性之間的關係。經過這些過程，得到10的4次方選擇比的選擇器。接著，製作氧化鉿為轉態層的電阻式記憶體。經過改良過程得到操作特性和已製備之選擇器匹配的電阻式記憶體。最終將這兩個元件進行搭配使用，得到一選擇器一電阻式記憶體之結構。透過模擬方程式確認選擇器可有效降低漏電流問題。若將讀取邊界設為10%，陣列大小可由N = 5大幅提升至N = 3408。

關鍵字

電阻式記憶體 ； 選擇器 ； 可撓式 ； 一電阻式記憶體一選擇器結構

並列摘要

Resistive random access memory (RRAM) is the most promising nonvolatile memory in the future, due to its serval advantages, low power consumption, high operation speed and 3D compatible architecture……etc. However, RRAM array suffers from sneak path current issue. It will cause memory array reading error and extra power consumption. Selector is one of the solutions. After RRAM connects with selector in series, selector can effectively reduce leakage current.
In this thesis, different oxides were deposited by sputtering as active layer of selector, and TaN was chosen as electrodes. First, TaO single layer was the only oxide and we adjusted different thickness to change electrical characteristics. Then, inserted different oxides to optimize its performance. In the same time we discussed the relationship between thickness combination and electrical characteristics. Therefore, we got 104 selectivity selector. Next we fabricated HfO-based RRAM. After optimization processes, the device operation current is match to the selector we had. Finally, these two devices are combined to form 1S1R structure. In the end, the ability of selector solving sneak path current issue and increasing the array size have been confirmed by simulation equation. If we set read margin at 10%, the array size increase to N = 3408 while single RRAM only has N = 5.

並列關鍵字

resistive random access memory ； selector ； flexible ； 1S1R

參考文獻

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